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Two part numbers, one package, one pinout, one peripheral set, and a factor of two between their flash arrays. The relationship is common enough in this family that images get moved between the members informally: a build is compiled for the larger part because the larger part is what the developer had, and a production run is fitted with the smaller one because that is what purchasing could get.

Sometimes that works. Sometimes it produces a unit that boots and misbehaves in a way nobody can attribute to anything, because the code that was moved is not the code that was tested. The difference is rarely the total size of the file. It is three specific addresses.

The three addresses

what	why it decides the port	how to find it
highest code address used	if it exceeds the smaller array, the code does not fit at all	the largest target of any branch or call in the disassembly
end of the constant tables	tables placed above the smaller array’s ceiling are simply absent	the highest address loaded through the program-memory pointer
the stack pointer initial value	a 256-byte stack frame in a 128-byte part overflows silently	the immediate loaded into the stack pointer at reset

The first is obvious and the second is often missed. A build can have compact code and a large table — a font, a lookup curve, a protocol string set — and the linker places that table after the code. On the larger part the table sits above the smaller part’s ceiling even though the code itself would fit. The result is a program that runs correctly until it first needs the table, then reads whatever the program-memory access returns outside the array, which on this hardware is not a fault but a value.

The third is the one that produces the least explicable symptoms. A stack that overflows its SRAM does not stop the processor. It corrupts whatever the stack pointer walks into, which is usually the region allocated to variables, and the corruption depends on call depth and interrupt timing. A unit that fails only under load, or only when a particular interrupt coincides with a particular function call, is a stack that is too deep for the part.

Why the jump instruction does not save you

A reasonable assumption is that the assembler would refuse to emit a relative jump that cannot reach its target. On a 4 KB array that assumption is true in a way that is unhelpful: a relative jump encodes a signed offset of twelve bits, which spans two thousand and forty-eight words, and 4 KB is exactly two thousand and forty-eight words. Every address in the array is reachable from every other.

So the toolchain has no reason to complain, the image links cleanly, and the fact that the code is destined for a 2 KB part changes nothing at build time. The constraint only appears when the image is executed on the smaller device, where the addresses above the ceiling do not exist.

This is also why the reverse direction is safe. An image built for the 2 KB part runs on the 4 KB part unchanged, because every address it uses is present in both. Downgrading is the risky direction; upgrading is not.

Reading the image to answer the question

The question «will this image run on the smaller part» is answerable from a disassembly in a short time, without recompiling anything:

1. Decode the vector table at address zero. Its length is set by the peripheral set and is identical on both parts.
2. Walk every branch and call target, and record the maximum. If it exceeds the smaller array’s word count, the answer is no.
3. Walk every program-memory load, note the base addresses handed to the pointer pair, and record the highest one. If any table base is above the ceiling, the answer is no even when the code fits.
4. Read the stack pointer immediate from the reset code, and compare the implied stack size against the SRAM of the smaller part.
5. Check the initialisation for a RAM test or a memory-clear loop, whose end address is a second, independent statement of how much SRAM the build expects.

Step 5 is the cross-check that catches a build compiled against the wrong device definition. A clear loop that stops at the top of a 256-byte SRAM is a build that was configured for the larger part, regardless of what the makefile said.

The EEPROM doubles too, and that truncates records

The capacity change is not confined to the flash array. This pair carries 128 bytes of EEPROM in the smaller part and 256 in the larger, so a configuration block that fits the smaller device may occupy only the first half of the larger array, and the reverse move silently cuts it in half.

That matters because EEPROM contents are rarely a flat parameter list. Where the structure is a rotating log — records written in sequence, the oldest overwritten when the array is full — the record at the top of the larger array is newer than everything in the smaller one. Copying the first 128 bytes of a 256-byte log therefore copies the oldest records and discards the current state, which is the exact opposite of what a migration is supposed to preserve.

The safe procedure is to identify the record structure before moving anything: fixed length, a sequence field or a timestamp, and a rule for which record is authoritative. Where the structure cannot be identified, the last written record is usually the one with a sequence number that is one higher than its neighbours, or the only one whose checksum validates against contents that are not all erased.

What this means for a recovery report

When the image is being recovered rather than ported, the same three addresses belong in the report for a different reason: they describe the memory the design occupies, and they tell the customer whether a replacement can be built on either member of the family. That is a purchasing question as much as an engineering one, and it is answered by the numbers the disassembly already produced.

The report should also state which member the image was built for, using the stack pointer constant as the evidence. It is a single number and it removes the ambiguity that the shared package creates.

The self-programming behaviour of the smaller member is covered in ATtiny2313 code recovery, and the revised silicon in ATtiny2313A heximal recovery. Where the same capacity question appears one family up, ATtiny261 code recovery covers the members that share an analogue front end.

FAQ

Can I tell the two parts apart from the image? Yes, from the stack pointer constant and from the highest address the code touches. Neither requires knowing the marking.

Does a larger part’s image always fail on the smaller one? No. It fails when the code or a table crosses the smaller ceiling, or when the stack outgrows the smaller SRAM. Small images port without change.

Is the pinout really identical? Yes within this pair, which is why the substitution happens in the first place and why the resulting faults are so hard to attribute.

Conclusion

Capacity-only siblings invite informal substitution, and the substitution is safe in one direction and conditional in the other. Three addresses settle it: the highest code target, the end of the constant tables, and the stack pointer initial value. None of them appear in a file size, and all three are visible in a disassembly that takes minutes to produce.

Most microcontrollers discussed in recovery work are flash or EPROM devices, and their protection is a bit that can in principle be defeated. The PIC16CR84 is not one of those. Its program memory is mask ROM — written at the factory by the diffusion mask itself. There is no erase operation, no configuration lock to clear, and no programming interface that could ever return the contents. Understanding that difference is the entire basis for reasoning about this part.

First, decode the part number

The PIC16C8x family is one of the most frequently misread in the whole PIC range, and the letters before the number are the reason. Four device types share the same 18-pin package, the same core, and the same pinout:

Prefix	Program memory	Voltage range	Erasable
C (e.g. PIC16C84)	EEPROM	Standard	Yes, electrically
F (e.g. PIC16F84)	Flash	Standard	Yes, electrically
LF (e.g. PIC16LF84)	Flash	Extended	Yes, electrically
CR (e.g. PIC16CR84)	Masked ROM	Standard	No — never
LCR (e.g. PIC16LCR84)	Masked ROM	Extended	No — never

So the CR prefix is not a revision or a temperature code. It denotes a device whose program was fixed at the wafer stage and cannot be changed by any means afterward. Any statement about “unlocking” a CR84 that assumes an erasable array is describing the wrong device.

The part in context

Property	PIC16CR84
Program memory	1K × 14 words, mask ROM
Data memory (RAM)	68 bytes
Data EEPROM	64 bytes
I/O pins	13
Package	18-pin PDIP/SOIC
Interrupt sources	4
Program memory type	Factory mask ROM

The 64 bytes of data EEPROM are worth pausing on. They are a separate, electrically writable region — masking the program did not remove them. In real products that block holds serial numbers, calibration offsets, or user settings written during test. A recovery effort that reaches the ROM array and stops there produces a program image with no idea what belonged in the EEPROM.

How mask ROM is programmed

There is no programmer involved. The customer supplies a code image to the manufacturer, and that image is converted into a photomask used during wafer fabrication. Each bit in the array is defined by whether a contact, via, or implant is present at that location.

That physical difference is exactly what makes the part recoverable at all, and it is also why the recovery is destructive. A programmed cell and an unprogrammed cell look different under a microscope — the presence or absence of a contact or an implant region produces a visible contrast. The information is not hidden behind a logic gate; it is written into the geometry of the silicon.

What “protection” means here

On a flash or EPROM part, the code-protect bit is a control that a read attempt hits and fails. On a mask ROM part, there is no read path to protect. The manufacturer’s masked devices were offered with code-protection options at mask time, but the practical outcome is the same as having no protection at all in one respect and stronger protection in another:

• No electrical route exists. No programming interface, no in-circuit serial programming, no debug access returns anything from the ROM array. There is nothing to glitch, because there is no gate evaluating a permission.
• No erasure is possible. The documented escape hatch on other parts — erase, accept the loss, start over — does not exist. A CR84 cannot be blanked, reused, or repurposed.

This inverts the usual asymmetry. Elsewhere, the temptation is that clearing protection destroys the code. Here there is no protection to clear and no code to destroy; the device is simply a read-only object, and the only question is whether someone images it.

The actual routes

Decapsulation and optical read. Remove the package, expose the die, and image the ROM array. Because the bit state is geometric rather than stored as charge, this is a visual problem: contrast between programmed and unprogrammed cells, resolved at the array’s pitch. For a 1K × 14 array this is a modest imaging task.

Microprobing. Where optical contrast is insufficient — for instance on a process where the implant difference is faint — the array’s sense amplifiers or bit lines can be probed directly, reading the array electrically from the inside.

Find a flash sibling. This is the route that is underused. Many products shipped in more than one variant, and the flash-based PIC16F84 carries the same core, the same instruction set, and often the same firmware. If a programmed F84 from the same product exists, reading it is far cheaper than imaging a ROM die. Related work on the flash side: PIC16F84 code recovery and PIC16F84 protection.

Reconstruct from behaviour. With 13 I/O and 1K words, a functional characterisation is plausible for simple control firmware, though it yields behaviour rather than code.

The mask-ROM sibling at half the array size is covered in PIC16CR83 recovery, and the flash-based smaller variant in PIC16F83 EEPROM recovery.

Why a CR84 is still worth recovering

Mask ROM parts were chosen for one reason: unit cost in volume. That means they are concentrated in exactly the products that shipped in the largest numbers — appliances, consumer electronics, simple industrial controls — designed through the 1990s and early 2000s. Those products have long service lives and long repair tails.

When such a unit fails and no spare exists, the mask ROM die is the only record of the firmware. Nothing was ever written down that could reconstruct it, because there was never a file to archive: the code went to the factory as a mask order and stopped existing as an artifact after the wafers were made.

Limits worth stating upfront

• Destructive by nature. Optical read requires removing the package; the device does not survive as a working part.
• No fallback. Unlike an EPROM part, there is no erase-and-retry cycle and no way to verify by reprogramming.
• The EEPROM block is separate. 64 bytes of data EEPROM must be captured independently, or the rebuild will be missing its calibration.
• 1K words caps complexity. A large state machine will not fit, which bounds what behavioural reconstruction can achieve.

FAQ

Can a PIC16CR84 be erased and reprogrammed? No. The program is defined by a fabrication mask. There is no erase mechanism and no programming interface for the array.

Is there a code-protect bit to defeat? Not in any practically meaningful sense. There is no read-back path to guard, so fault injection has no target on this part.

How is the code read, then? By exposing the die and imaging the ROM array, where programmed and unprogrammed cells differ geometrically, or by probing the array electrically.

Why do I also need the 64 bytes of EEPROM? Because that block is separately writable and typically holds calibration or identification written during production. The ROM image alone is incomplete.

Conclusion

The PIC16CR84 is the case that makes the difference between protecting code and never storing it in a readable form concrete. There is no lock to pick, because there is no lock — the code exists as geometry on the die, and the only way to it is to look. That makes the problem simpler to reason about and harder to solve: simpler because the route is unambiguous, harder because it always costs the device.

The PIC16C710 is the smallest member of Microchip’s PIC16C71X family, and that single fact reshapes everything about attacking it. Most protection discussions assume a large firmware image where the difficulty is extracting megabytes without error. Here the entire program is 512 instruction words. The difficulty is not volume. It is that the part is EPROM, that the code-protect bit lives in the same array as the code, and that the documented way to clear the bit destroys what it protects.

The part in context

Before going further, one correction worth making explicitly, because it propagates widely: the PIC16C71X datasheet header advertises “up to 2K × 14 words of program memory, up to 128 × 8 bytes of data memory.” Those are the family maximums, reached by the PIC16C715. They are not the PIC16C710’s specifications.

Property	PIC16C710
Program memory	512 × 14 words EPROM
Address range	0000h–01FFh
Data memory (RAM)	36 bytes
I/O pins	13
Timer modules	1 (Timer0)
A/D converter	4 channels, 8-bit
Package	18-pin PDIP/SOIC, 20-pin SSOP
Supply	2.5 V – 6.0 V
Brown-out reset	Yes
In-circuit serial programming	Yes

The family’s 13-bit program counter can address 8K × 14, but only the first 512 words are implemented here. Accessing an address above 01FFh causes a wraparound, not a fault — a behaviour that matters when reading a dumped image, because a wraparound can make a truncated read look complete.

Memory organisation

The reset vector is at 0000h and the interrupt vector at 0004h, so the first eight words are effectively fixed: a jump to the main routine, and a jump to the interrupt handler. Everything the device does is reachable from those two addresses.

Data memory is organised in banks of 128 bytes, with the Special Function Registers occupying the low addresses of each bank and General Purpose Registers — implemented as static RAM — above them. With only 36 bytes of GPR available, the firmware cannot afford abstraction. State is held in SFRs and a handful of bytes, which has a useful side effect for anyone reading a recovered image: there is nowhere for the code to hide. A 512-word program using 36 bytes of RAM is close to self-documenting once the SFR accesses are annotated.

The A/D converter is the other fixed point. Four channels of 8-bit conversion implies reference and scaling constants, and on a part this small those constants are typically sitting in the last few words of the array as a look-up table or as inline literals.

How code protection works here

Configuration bits on this family are programmed at address 2007h, which is part of the same EPROM array as the program. The code-protect bit, when programmed, prevents the program memory from being read out over the programming interface — including in-circuit serial programming.

The consequence is structural rather than procedural. Because the configuration word and the program live in one array, there is no operation that clears the code-protect bit while leaving the program intact. On a windowed CERDIP part, ultraviolet erase clears both together. On an OTP part, there is no erase path at all, so the barrier is permanent for that device.

This is the same design pattern found across the microcontroller world — the mechanism differs, the asymmetry does not. PIC16C711 code protection shows the identical arrangement on the next part up, and PIC16C71 program recovery covers the original variant.

What attacking it can mean

Four routes exist, in increasing order of cost.

Read over the programming interface. With the bit clear this is trivial: the programmer reads 512 words plus the configuration word and emits a hex file. With the bit set, the device returns nothing useful. Note that the protection does not necessarily announce itself — a protected read may return zeros or all-ones rather than an error, so a “successful” dump must be validated before it is believed.

Manipulate the configuration word. Attempting to reprogram 2007h to clear the bit initiates the erase sequence, and the program goes with it. This is the trap, not the solution.

Fault injection at the protection check. The code-protect condition is evaluated by on-chip logic when a read is requested. A precisely timed supply or clock disturbance during that evaluation can cause the check to be mis-evaluated for a cycle, allowing a read before protection reasserts. It is non-invasive and preserves the die, but it is timing-critical, and results vary with silicon revision.

Physical read. After decapsulation, EPROM cells can be examined directly: floating-gate cells holding charge are distinguishable from erased ones. On a 512-word array this is unusually tractable, because the array is small enough to image at high magnification in a small number of passes.

Why a part this small still matters

The PIC16C710 appears in enormous volumes of appliance control, thermostats, pressure sensing, and small motor drives designed through the late 1990s and 2000s. Those products are still manufactured and still repaired. The datasheet describes the A/D converter as suited to “low-cost analog interface, e.g. thermostat control, pressure sensing” — and that is exactly where the part ended up.

When such a product’s firmware is lost, the consequences are disproportionate to the chip’s size: a 512-word program is the entire control law of the appliance, and no schematic contains it. Related parts in the same family show identical constraints at slightly larger sizes — PIC16C712 protection and PIC16C715 firmware.

Limits worth stating upfront

• OTP parts cannot be reused. There is no erase, so any invasive route ends the device.
• The family header misleads. Reading “2K × 14” as this part’s capacity leads to expecting twice the image that exists.
• Wraparound hides truncation. A read that stops early can alias and appear complete.
• 36 bytes of RAM constrains nothing about difficulty. Small firmware is not simple firmware; the control law can still be dense.

FAQ

How much program memory does the PIC16C710 really have? 512 × 14 words, addressed 0000h–01FFh. The 2K × 14 figure in the datasheet features list is the family maximum, belonging to the PIC16C715.

Does in-circuit serial programming bypass code protection? No. ICSP is the interface the protection is enforced on. It allows programming and, with the bit clear, reading; with the bit set it allows neither read-out nor a partial unprotect.

Why does a protected read sometimes look like a valid dump? Because the interface may return zeros or ones rather than reporting a failure. Validation against known vectors — reset behaviour, a handful of A/D conversions — is what separates a real image from a flat one.

Is the 8-bit A/D relevant to recovery? Yes. Reference and scaling constants for the converter are usually embedded in the image, and a recovered program without them can run correctly and still produce wrong measurements.

Conclusion

Attacking a PIC16C710 is a small-array problem with a large structural obstacle: the code-protect bit shares its EPROM array with the code, so clearing it clears the program. What makes this part workable is its scale — 512 words of image, 36 bytes of state, one timer, four A/D channels. There is very little surface for a firmware to hide in, which means a successful read is usually followed by comprehension rather than by months of analysis.

Related reading

• PIC16C711 code protection
• PIC16C712 protection
• PIC16C715 firmware
• PIC16C71 program recovery
• Breaking IC protection

A trailing letter is the least dramatic change in a part number and the one that causes the most confusion in a recovery. It does not normally mean a different memory size or a different pinout. It marks a revision: the same design with corrected or improved silicon behind it, sometimes with a wider specification and almost always with its own errata list.

For the person holding the part, that creates a problem with three separate answers. What the package says, what the interface reports, and what the calibration value implies are three different statements about identity, and they do not have to agree.

What a revision letter changes and what it does not

Across this family the storage map and the peripheral set stay fixed: 2 KB of flash, 128 bytes of SRAM, 128 bytes of EEPROM, twenty pins, a USART, an SPI port, a universal serial interface, two timers, an analogue comparator. Code written for one revision runs on the other, because the instruction set and the register map are the same.

What moves is the specification envelope and the defect list. Supply range, maximum frequency at a given voltage, current consumption, the behaviour of a peripheral under a corner condition — these are the things a revision adjusts, and they are exactly the things a fuse configuration encodes. That is the practical consequence: a fuse map copied from a non-A device onto an A device may put the newer part outside its specified operating point even though every bit is a legal bit.

property	same across revisions	may differ
flash, SRAM, EEPROM size	yes	—
pinout and package	yes	—
instruction set	yes	—
signature bytes	—	possible
oscillator calibration	—	yes, per device and per revision
fuse defaults and safe limits	—	yes
errata	—	yes

The signature answers a narrower question than people expect

The three signature bytes report the manufacturer, the family and the memory class. They are read with a dedicated command that does not consume a flash address, which makes them the cheapest identity check available and the first thing to obtain.

What they do not report is the revision in any reliable form. Two devices built from different masks can return the same signature, and the same part number from two production runs can differ in behaviour without differing in signature. So a matching signature proves the interface works and the family is right. It does not prove the marking is honest.

The calibration value is the per-device fingerprint

Every one of these parts is calibrated at test, and the result is stored in a row that is separate from the flash array. That value tunes the internal oscillator, and because it is measured rather than assigned, it varies from device to device within a distribution set by the process.

Two uses follow. The first is functional: an image restored onto a different physical part inherits the donor’s calibration unless the row is rewritten, and the timing consequences range from negligible to fatal depending on whether the design depends on the internal oscillator for a communication rate.

The second is forensic. A batch of genuine parts from one production period has calibration values clustered in a predictable band. A part whose marking says one revision, whose signature says the family, and whose calibration value sits far outside the band for that revision is worth a second look — that combination is characteristic of remarked or refurbished material, which is common in the second-hand market this family ends up in.

The marking is a claim, not a measurement

Laser marking is applied after test and can be removed and reapplied. On a twenty-pin plastic package the operation is not difficult, and the economic incentive is real because the A revision often trades at a different price from the older part.

That does not make every package suspect. It does mean the marking should be treated as the weakest of the three sources rather than the primary one, and that a report which records only the marking is recording the customer’s belief rather than the silicon’s answer.

Reading order for an identity dispute

When the question is specifically «which revision is this», the sequence that settles it without destroying evidence:

1. Read the signature. Establish that the interface works and the family is correct.
2. Read the fuse and lock bytes as found. They state the operating point the device was configured for, and comparing them against the defaults for the claimed revision is informative.
3. Read the calibration row. Compare against the expected band.
4. Read the flash, if the lock state allows it, and check the oscillator setup in the initialisation code. A build that programs the divider or selects an external clock is telling you what it expected the part to be.
5. Only then compare against the marking.

Steps 1 to 3 are non-destructive. Step 4 may require the erase, so it comes after the decision about whether the flash contents are needed.

What the recovery returns

For a heximal-level job the deliverable is the flash image with the correct length for a 2 KB array, the EEPROM as a separate file, the signature, the calibration value and the fuse and lock state as read, and a disassembly annotated with the register configuration the image assumes.

Recording the calibration value is not decoration. It is the only per-device datum in the set, it cannot be reconstructed from the image, and a customer who later moves the image to another unit needs it to restore the timing the design was built around.

The unsigned variant’s own behaviour under erase is covered in ATtiny2313 code recovery. Where the same package carries 4 KB, ATtiny4313 code recovery follows the migration. The same identification discipline applied to a part with an ambiguous suffix appears in ATtiny48V firmware recovery.

FAQ

Does the A suffix mean more memory? No. The array size is unchanged across the revisions of this part; the suffix marks silicon revision and with it the specification envelope.

Can a fuse map be copied between revisions? The bits will be accepted, but the resulting operating point may be outside the newer part’s specification. Fuse maps belong to a part, not to a family.

Why does the calibration value matter if the code runs? It sets the internal oscillator. Code that runs at the wrong frequency may still execute, and still fail every timing-sensitive function it performs.

Conclusion

Identity on a revised part is a three-way question with three partial answers: the marking states a claim, the signature confirms a family, and the calibration value places a specific device in a production distribution. Read all three, in that order of reliability rather than the order printed on the box, and the revision question stops being a matter of opinion.

Most images have one author: whatever programmer wrote them at the factory or on the line. Some images have two, because the firmware can rewrite its own flash, and when that is the case the array is not a snapshot of a build — it is the current state of a process that may have stopped in the middle.

On a twenty-pin part with 2 KB of flash that distinction is unusually tractable. The array is only thirty-two pages. An interrupted self-update leaves evidence in one of them, and finding which one is a matter of arithmetic rather than archaeology.

The mechanism, in the order it happens

Self-programming on AVR is not a store instruction. It is a sequence of writes to a control register, each one triggering a hardware operation that runs to completion after the instruction retires:

1. Erase the target page. The whole page goes to 0xFF, not just the bytes about to be written.
2. Fill the page buffer, one word at a time, through a temporary register pair.
3. Commit the buffer to the page in a single write.

Two properties follow from that sequence and both matter during a recovery. The first is that a page is the unit of destruction: rewriting four bytes costs the other sixty. The second is that the sequence has intermediate states, and a power loss between any two of them leaves a page that is neither old nor new.

interruption point	page state	what it looks like in the image
before the erase	old contents intact	nothing to see
after the erase, before the commit	all 0xFF	a hole in the middle of otherwise dense code
during the buffer fill, before the commit	still all 0xFF	same as above; the buffer is volatile
after the commit, before verification	new contents, unverified	valid code that may be truncated

The middle two rows are the reason a hole of erased bytes inside a region of dense code is worth investigating rather than dismissing. On a part that was programmed once and never updated, erased bytes appear only at the top of the array. Anywhere else, they are a scar.

Why 2 KB makes this cheap to analyse

Thirty-two pages of sixty-four bytes means the page map fits on one line. Walk the array page by page and classify each one as dense, sparse or blank, and the layout of the firmware becomes visible without reading a single instruction:

• the vector table occupies the first page, and possibly part of the second;
• initialisation and the main loop follow in dense pages;
• string and table data tend to occupy pages with a regular repeating structure;
• blank pages appear at the top, and anywhere else they are candidates for an interrupted write.

That classification takes minutes and it answers a question that otherwise gets answered badly: whether the image is a clean build or the survivor of a failed field update. The difference matters commercially, because the second case usually means the customer has a second unit that was updated successfully, and that unit is a better source than the damaged one.

The vector table as a fixed cost

Every interrupt source needs an entry, and on this family each entry is a two-word relative jump. The count of entries is set by the peripheral set: two timers, a USART with its separate receive, transmit and data-register-empty sources, an analogue comparator, an external interrupt pair, a pin-change group, a watchdog, and the EEPROM-ready source.

That works out to a table of roughly thirty to forty words, which is between one and two percent of a 2 KB array. Small in absolute terms, and large enough that it constrains what fits: a 2 KB part running a USART protocol stack has very little left for application code, and that is why images on this part are usually written in assembly with attention to every byte.

It also gives a verification tool. The table is at a known address, its entries are a known instruction form, and any deviation is either an unused entry left as a jump-to-self or the mark of a build that disabled an interrupt. Both are readable, and a table that does not decode at all means the image starts at the wrong base address.

The USART register writes as a chronology

Because the part is normally chosen for its serial port, almost every image contains a USART initialisation block: baud rate registers, frame format, enable bits. That block is a timestamp of sorts. The baud divisor is computed from the clock frequency, so the pair of constants written to the baud registers states the clock the build assumed, and comparing it against the board’s actual oscillator resolves the most common «restored image runs at the wrong speed» complaint.

The frame format register says something else: whether the design used the port for a simple debug channel, in which case the configuration is minimal and the transmit path is a blocking loop, or for a real protocol, in which case there are receive interrupts, buffers and state machines. The second kind of image is longer, denser and usually the one worth reconstructing in full.

What is delivered

The return set for a code-level recovery on this part is the flash image as Intel HEX, the EEPROM as a separate file, the fuse and lock state as read, a disassembly with the SPM sequence and the USART configuration annotated, and a page map marking any region that looks like an interrupted write.

The page map is the part of the deliverable that customers did not ask for and consistently use. It says whether the image in hand is the original build or the result of an update that stopped, and those two answers lead to different next steps.

Where the same package carries twice the flash, ATtiny4313 code recovery covers what changes when code is moved between them. The variant with revised silicon is discussed in ATtiny2313A heximal recovery, and the wider vector table of the next part up in ATtiny261 code recovery.

FAQ

Can self-programming be detected from the image alone? Yes. The control-register sequence is distinctive and appears in a small number of routines that are then callable from the update path.

Does an erased page always mean a failed update? No. It can also be an unused page inside a build, but on this part the linker packs from the bottom, so a hole in the middle deserves a second look.

Is the page buffer readable after a power loss? No. It is volatile, which is why an interrupted fill leaves the page erased rather than partially written.

Conclusion

A part that can rewrite its own flash produces images that record their own history. The page is the unit of destruction, the sequence has three steps with a gap between each, and a 2 KB array is small enough to classify page by page in a few minutes. That classification is the difference between reporting a build and reporting the state of an update that failed.

Every AVR recovery that involves clearing protection runs into the same physical fact: the operation that removes the lock bits also erases the array. There is no separate unlock command. The erase is the unlock.

That fact is usually stated as bad news and left there. On this family it is more interesting than that, because the erase is not a single action covering a single memory. It covers three, and one bit in the fuse configuration decides whether the smallest of them is included. That bit is read without disturbing anything, it takes a second to obtain, and it determines which of two quite different procedures is safe.

Three memories, two erase behaviours

The device holds flash for code, SRAM for working state, and EEPROM for data that has to survive a power cycle. Of these, two are non-volatile and both are affected by a chip erase — but not identically.

memory	contents	survives chip erase	endurance
flash	program and constants	no	about 10,000 cycles
EEPROM	calibration, counters, settings	depends on one fuse bit	about 100,000 cycles
SRAM	working state	irrelevant, gone at power-off	unlimited

The fuse is called EESAVE and it is programmed rather than cleared to preserve. In the state where it is programmed, a chip erase clears the flash and the lock bits and leaves the EEPROM contents untouched. In the other state, the EEPROM is erased along with everything else.

Why this changes the order of work

Consider a part whose lock bits prevent reading the flash but whose EEPROM is the thing the customer actually needs — a unit counter, a calibration table, a serial number that was never written down. Two procedures exist and they lead to different places:

• If EESAVE is programmed, running the erase clears protection and flash, and the EEPROM can then be read through the ordinary interface. The code is gone, the data is not. That is often an acceptable trade, and it costs nothing but a reflash of an image that probably exists in the customer’s source control anyway.
• If EESAVE is not programmed, the same erase destroys both memories. The job then has to go to the silicon, which is a different service at a different price.

The entire decision rests on one bit that can be read before anything is touched. Skipping that read is the single most expensive shortcut available on this part, and it is taken routinely by operators who have learned that «chip erase unlocks the chip» and stopped there.

Reading the fuse state first

The fuse bytes are readable through the interface on a part whose lock bits are set, as long as verification has not been disabled entirely. That is the first operation, before any erase, before any attempt at the flash array:

1. Read the signature. If it does not answer, stop; the problem is electrical and no fuse will help.
2. Read the lock bytes. They say which operations the part will accept.
3. Read the fuse bytes. They say what an erase will destroy.
4. Only now decide whether an erase is part of the plan.

Steps 1 to 3 are non-destructive and take under a minute. Their output is the entire basis for the choice in step 4, and it also documents what state the part was in when it arrived — which matters when a customer later claims the part was working.

What the EEPROM contents reveal

When the EEPROM does survive, its contents are worth more than a data dump. The endurance figures are the reason: flash in this class is rated around ten thousand write cycles and EEPROM around a hundred thousand, an order of magnitude apart. A page that has been rewritten on every power-up shows a different wear signature from one written once at the factory.

In practice that shows up as data that is still valid but sits in a page whose neighbours are inconsistent, or as a structure that looks like a rotating log — a sequence of records walking through the address space, each with a sequence number that only ever increases. Recovering such a structure is a matter of ordering records, not of reading bytes, and the last valid record is the answer the customer wants.

When the fuse says the data is gone

If EESAVE was left in its erase-inclusive state, the data page is not recoverable by any interface operation, and the honest answer is that the erase that would unlock the flash will also clear the EEPROM. The work then proceeds at die level, where the EEPROM array is read directly out of the silicon before any electrical erase is applied.

That path is slower and more expensive, but it is not speculative. The EEPROM array on this family is a distinct physical structure with its own row address decoder, and reading it does not depend on the flash lock bits in any way. What it does depend on is the package: an eight-pin plastic part is a straightforward decapsulation, and the array is small enough that the read is quick once access exists.

The deliverable, and the note that matters

The return set is the flash image, the EEPROM contents as a separate file because it is a separate address space, the fuse and lock bytes exactly as read on arrival, and a statement of which of the two paths was taken and why. That last item is not administrative. A customer who is told «the EEPROM was preserved because EESAVE was set» learns something about their own production programming that they did not know, and the same customer who is told the opposite learns that the setting needs changing in the fixture.

Protection semantics on this variant are otherwise identical to the rest of the family, and what the same die looks like when the firmware turns out to be a software USB stack is covered in ATtiny85 flash reverse engineering. The low-voltage electrical constraints are covered in ATtiny45V program recovery, and the identification of the three pin-compatible members in ATtiny45 heximal extraction. For images where the EEPROM is used as a rotating log rather than a settings page, the same reasoning appears in ATmega1280 EEPROM recovery.

FAQ

Can the EEPROM be read while the flash is still locked? Not through the array read, which the lock bits cover. The fuse bytes are readable, and they decide whether a later erase will spare the data.

Is EESAVE programmed by default? It is not, which is the reason an unplanned chip erase so often takes the data page with it.

Does preserving the EEPROM mean the code can be recovered afterwards? No. The erase that clears the lock bits clears the flash regardless of EESAVE. Only the data survives.

Conclusion

«Chip erase unlocks the part» is true and incomplete. It is one operation with two possible scopes, and a single fuse bit selects between them. Reading the fuse bytes before touching anything costs a minute and decides whether the customer gets a data page back or a quotation for decapsulation.

An eight-pin part with no USB peripheral is not the obvious place to find a USB device, and yet a large share of ATtiny85 designs in the wild are exactly that. The part has enough pins, enough flash and a fast enough core for a software implementation of low-speed USB, and the reference implementation for it has been copied into thousands of small products.

That fact is worth knowing before opening the disassembly, because it changes the order in which the image should be read. A general-purpose AVR image is read from the reset vector forward, following initialisation into the main loop. A software USB image is read from its timing loops outward, because those loops are the most constrained code in the part and everything else is arranged around them.

What the part actually provides

The ATtiny85 carries 8 KB of flash, 512 bytes of SRAM, 512 bytes of EEPROM, an eight-bit timer with PWM, a second eight-bit timer, a four-channel ten-bit converter, a comparator, a universal serial interface, and six usable I/O pins on the eight-pin package. There is no USB controller anywhere in that list.

Software USB therefore has to bit-bang a 1.5 Mbit/s differential signal on two ordinary port pins, with edge timing accurate to a small fraction of a 0.667 microsecond bit period, while the same core also runs the application. It works because the task is bounded: low-speed USB is slow by modern standards, and an AVR running at 16 MHz has roughly ten instruction slots per bit.

constraint	figure	consequence in the image
bit period	0.667 µs	a tight loop whose cycle count is the specification
core clock used	16 to 16.5 MHz from the internal PLL	PLL control written early, before any USB traffic
SRAM available	512 B	endpoint buffers, descriptors and application state compete for one page of memory
signal pins	two port pins, usually adjacent	direction and level written as whole-port operations

The PLL write is the first landmark

The internal oscillator tops out below what the timing needs, so designs enable the phase-locked loop and run the core from it. That is a write to a specific control register in the first few dozen instructions of the program, before timers are configured and long before any pin is touched.

For a reader, that write is the entry point. It says the design intends to run fast, and it dates the code: designs built around the PLL are the ones that can afford software USB, and designs running from the plain 8 MHz oscillator cannot. Finding it also fixes the clock frequency the rest of the analysis assumes, which is the number every delay loop is calibrated against.

The bit engine

The timing-critical code is small, and it looks unlike anything else in the image. It is a loop with a fixed instruction count, entered from a timer interrupt or from a pin-change interrupt, containing shifts, conditional branches on a port bit, and whole-port writes. It has no floating point, no table lookups and no calls into application code, because a call would blow the cycle budget.

Two features make it identifiable even without a symbol table. The first is that it reads a port pin and writes the same port within a handful of instructions. The second is that its branch structure corresponds to the USB line states: idle, start of packet, and the two data states. Once that loop is labelled, the rest of the protocol layer is findable by following its callers.

Descriptors live in flash, not in SRAM

A USB device has to answer requests for its device, configuration and string descriptors. On a part with 512 bytes of SRAM, those tables cannot live in RAM; they are constants in flash, read back with the load-from-program-memory instruction using a pointer pair.

That produces a distinctive pattern in the disassembly: short routines that take a descriptor index, add it to a base address, and copy bytes out of flash one at a time. String descriptors in particular are recognisable because they contain the UTF-16 encoding of a product name, which appears as readable text when the flash image is dumped as bytes. A vendor and product identifier pair stored as two sixteen-bit constants nearby is the second confirmation.

This is also the fastest route to a human-readable answer for a customer. Before any semantic analysis, the descriptors usually say what the product claims to be.

Where the application begins

Everything past the protocol layer is ordinary embedded code: an ADC read for a sensor, a PWM write for a motor or an LED, a state machine driven from the main loop. It is reached from the protocol layer when a control request asks the device to do something, and it is usually the least optimised code in the image because it has slack.

Reading outward from the timing loops therefore has a practical benefit beyond elegance. The parts of the image that are most expensive to reconstruct are the ones that are read first, while attention is fresh, and the parts that are routine are read last.

What a complete deliverable looks like

For an image of this shape the return set is the flash contents as Intel HEX, the EEPROM as a separate file, a disassembly with the PLL and timer configuration annotated, the descriptor tables extracted into readable form, and a map of which routines implement the protocol and which implement the application. The descriptor extraction is worth calling out separately because it is the part of the work most often useful to someone who is not going to read the assembly at all.

The image is also the only place the calibration value can be confirmed. Designs built on the internal oscillator store a per-device calibration byte, and an image restored to a different physical part inherits the donor’s calibration rather than the target’s. That does not stop the code running, but it does move the timing, and on a software USB design timing is the product.

The family’s pin constraints are covered in ATtiny25 flash recovery, and the erase behaviour that decides whether the EEPROM survives in ATtiny85V software recovery. Where the same part appears with more flash and a wider vector table, ATtiny45 heximal extraction covers the identification step.

FAQ

Does this part have hardware USB? No. Everything is done in software on two general-purpose pins, which is why the timing loops are the most constrained code in the image.

Why does the descriptor table matter? It answers what the device claims to be, in text, without requiring the assembly to be understood first.

Is the calibration byte part of the image? It lives in a separate signature row rather than in the flash array, but an image moved to another device carries the donor’s timing unless that row is rewritten.

Conclusion

An eight-pin part with no USB peripheral still produces images that enumerate over USB, and those images have a shape: a PLL write early, a fixed-cycle bit engine, descriptor tables in flash, and application code reached from the protocol layer. Knowing the shape turns an 8 KB disassembly from a wall of instructions into a structure with an obvious first page.

The CPLD XC9536XL-10VQG44C is a widely adopted PLD device known for its reliability, low power consumption, and flexible logic configuration in embedded systems. Commonly deployed across industrial automation, medical instrumentation, automotive control modules, and communication equipment, this component plays a critical role in managing timing logic, signal routing, and interface control. Its compact architecture and non-volatile memory make it ideal for applications requiring stable and repeatable execution of embedded program logic. However, in many scenarios, the internal firmware or source code stored inside the chip is protected, locked, or even encrypted, preventing direct access to valuable data, binary, or heximal design files.

Our specialized service for “Attack CPLD XC9536XL-10VQG44C Software” is designed to attack, break, and decode these secured devices in a controlled and professional manner. Through advanced techniques such as decapsulate processes, electrical analysis, and protocol-level exploitation, we are able to retrieve critical firmware, extract binary or heximal file structures, and reconstruct the original source code or logic configuration. Whether the target is stored in internal flash, EEPROM, or embedded memory, our engineers can effectively hack through multiple layers of protective and secured mechanisms. The extracted data archive can then be analyzed, allowing clients to clone, duplicate, or redevelop the original program with high accuracy. This process ensures that even heavily encrypted or locked CPLD devices can be transformed into accessible engineering resources.

We can Attack CPLD XC9536XL-10VQG44C Software, please view below CPLD XC9536XL-10VQG44C features for your reference:

Features

· 5 ns pin-to-pin logic delays

· System frequency up to 178 MHz

Product Specification

54V18 Function Blocks, providing 800 usable gates with propagation delays of 5 ns. See Figure 2 for architecture overview.

36 macrocells with 800 usable gates

Available in small footprint packages

– 44-pin PLCC (34 user I/O pins)

– 44-pin VQFP (34 user I/O pins)

– 48-pin CSP (36 user I/O pins)

– 64-pin VQFP (36 user I/O pins)

– Pb-free available for all packages

Optimized for high-performance 3.3V systems

– Low power operation

– 5V tolerant I/O pins accept 5 V, 3.3V, and 2.5V signals

– 3.3V or 2.5V output capability

– Advanced 0.35 micron feature size CMOS Fast FLASH™ technology

Advanced system features

– In-system programmable

– Superior pin-locking and routability with

Fast CONNECT™ II switch matrix

– Extra wide 54-input Function Blocks

– Up to 90 product-terms per macrocell with individual product-term allocation

– Local clock inversion with three global and one product-term clocks

– Individual output enable per output pin

– Input hysteresis on all user and boundary-scan pin inputs

– Bus-hold circuitry on all user pin inputs

– Full IEEE Standard 1149.1 boundary-scan (JTAG)

Fast concurrent programming

Slew rate control on individual outputs

Enhanced data security features

Excellent quality and reliability

– Endurance exceeding 10,000 program/erase cycles

– 20 year data retention

– ESD protection exceeding 2,000V

Pin-compatible with 5V-core XC9536 device in the

Power Estimation

Power dissipation in CPLDs can vary substantially depending on the system frequency, design application and output loading when Attack CPLD. To help reduce power dissipation, each macrocell in a XC9500XL device may be configured for low-power mode (from the default high-performance mode).

In addition, unused product-terms and macrocells are automatically deactivated by the software to further conserve power.

For a general estimate of ICC, the following equation may be used:

ICC(mA) = MCHS(0.175*PTHS + 0.345) + MCLP(0.052*PTLP + 0.272) + 0.04 * MCTOG(MCHS +MCLP)* where if Attack CPLD:

MCHS = # macrocells in high-speed configuration

PTHS = average number of high-speed product terms per macrocell

MCLP = # macrocells in low power configuration

PTLP = average number of low power product terms per macrocell

f = maximum clock frequency

MCTOG = average % of flip-flops toggling per clock (~12%)

This calculation was derived from laboratory measurements of an XC9500XL part filled with 16-bit counters and allowing

a single output (the LSB) to be enabled. The actual ICC value varies with the design application and should be verified during normal system operation. Figure 1 shows the above estimation in a graphical form. For a more detailed discussion of power consumption in this device, see Xilinx 44-pin PLCC package and the 48-pin CSP package.

WARNING: Programming temperature range of TA = 0° C to +70° C

Description

Technically, the workflow involves both physical and logical approaches. On the physical level, decapsulation exposes the silicon die for direct probing, while non-invasive methods may also be applied to decode configuration bits. On the logical level, we utilize proprietary algorithms to reconstruct firmware structures from raw binary dumps, converting them into usable source code or structured data files. This enables efficient retrieval and validation of embedded logic. By combining these approaches, we ensure a high success rate in breaking protection schemes and delivering accurate archive outputs. Clients can then clone or duplicate the CPLD design for maintenance, redesign, or compatibility upgrades without needing the original development files.

The demand for such services continues to grow as industries face challenges like component obsolescence, lack of documentation, and supply chain disruptions. By leveraging our capability to attack, decode, and restore secured CPLD memory, end users gain full control over their hardware assets. This not only reduces redevelopment costs but also accelerates product lifecycle management. Whether the goal is to recover lost firmware, analyze a competitor’s embedded design, or replicate a legacy system, our service provides a reliable pathway to access, understand, and reuse critical data locked within the XC9536XL-10VQG44C.

The V suffix is not a marketing label. It marks a part specified down to 1.8 V, and the price of that lower floor is a lower ceiling on clock frequency at the bottom of the range. Both figures move together, and both of them decide whether a programmer that works perfectly on an ordinary ATtiny45 will work at all on an ATtiny45V.

The practical consequence is a failure mode that misleads almost everyone the first time. The adapter reports no device, or a signature of 0x00 0x00 0x00, and the natural conclusion is a dead chip or an enabled lock bit. Most of the time it is neither. It is a level or a clock that the target cannot accept.

What the V suffix changes

The non-V part is specified from 2.7 V to 5.5 V and reaches its top speed at 5 V. The V part extends the bottom of the range to 1.8 V, but the maximum frequency falls as the supply falls: a device running at 1.8 V cannot be clocked at the rate it manages at 5 V. That is a silicon property of the process, not a documentation quirk, and it applies to every member of the family.

For a recovery the important part is not the headline speed. It is that a 1.8 V design is a 1.8 V design all the way through: a coin cell, a lithium primary, two alkaline cells. Those boards are built to run at the bottom of the range, and everything attached to them, including the programming header, was chosen with that in mind.

Failure one: the programmer supplies 5 V

Most bench programmers source target power, and most of them source 5 V, because that is what the parts they were designed around wanted. Connecting one to a board whose rail is 1.8 V creates a conflict between two supplies with no arbitration. The current that flows depends entirely on the board, and the outcomes range from harmless to destructive:

• the programmer’s 5 V back-feeds the board’s regulator, which may survive, may clamp, or may not;
• the board’s rail is dragged up toward 5 V, and every other device on it is now over its absolute maximum;
• the target runs, the interface works, and the damage is done quietly to something else on the same rail.

The safe arrangement is to power the target from its own supply and connect only ground plus the four interface lines, then confirm that the programmer is not driving its own VCC onto the header. Many adapters do this through a jumper that is easy to leave in place.

Failure two: the levels do not meet

Even with the supplies separated, the signal levels have to be compatible. A programmer driving 5 V logic highs into a target running at 1.8 V presents the target’s pins with a voltage above their absolute maximum rating. Some parts tolerate it briefly, some latch up, and none of them are specified to.

The reverse direction fails differently. The target’s 1.8 V high may sit below the programmer’s input threshold, so the programmer reads every response bit as a zero. That produces a signature read of all zeros, which is precisely the result an operator interprets as «protected».

A level translator solves both directions, and a programmer with a variable supply solves them more simply. What does not solve them is trying harder with the same cable.

Failure three: the interface clock is too fast

The serial programming interface has a hard rule: its clock must be no faster than a quarter of the target’s operating clock. The rule exists because the interface is sampled by the target’s own clock, and the target must be able to see each edge.

Here the V part has two compounding problems. The internal oscillator is divided down at reset by a fuse that ships enabled, so a factory-fresh device runs at a nominal 1 MHz rather than the 8 MHz the oscillator produces. A quarter of that is 250 kHz. Programmers commonly default to a much faster rate because it works on parts running at 8 or 16 MHz, and on a fresh V part it does not work at all.

target clock	maximum interface clock	typical programmer default
1 MHz (factory divide enabled)	250 kHz	too fast
8 MHz (divide disabled)	2 MHz	usually fine
128 kHz (internal low-power oscillator)	32 kHz	far too fast

The 128 kHz row is the one that ends arguments. A design that runs from the low-power watchdog oscillator has an interface ceiling of 32 kHz, which is slow enough that some adapters cannot go that low and the job has to be done with a different tool.

Establishing the target clock independently

Because the interface speed is derived from a clock that cannot be read from outside, it has to be inferred. Three sources agree often enough to be trusted:

1. The fuse read, if it can be obtained at all, says whether the divide-by-eight is enabled.
2. The board itself says a great deal: a crystal or resonator sets the clock, and its absence points at an internal oscillator.
3. The firmware’s timing loops say the rest. A delay loop calibrated for 1 MHz and one calibrated for 8 MHz differ by a factor of eight in their constants, and that ratio is visible in the disassembly once the image is out.

That last route is the reason the clock question is not blocking. It is answered after the read rather than before it, and it is recorded in the report so the next person does not have to rederive it.

What is actually being delivered

A program-level recovery on this variant returns the flash image, the EEPROM as a separate file, the fuse and lock bytes as read, a disassembly with the peripheral registers annotated, and a note stating the supply range and the clock the image was built for. That note is the difference between an image that gets reflashed successfully and one that appears to work on the bench and fails in the field, because a build compiled for 8 MHz does not keep time on a board that runs at 1 MHz.

Protection itself is unchanged from the rest of the family; the two lock settings behave the same way as on the non-V part. The low-voltage variant simply adds two constraints before any of that becomes reachable. The non-V part’s constraints are covered in ATtiny45 heximal extraction, and the EEPROM behaviour under erase in ATtiny85V software recovery.

The same clock question reappears on much larger arrays, where a design that assumes one frequency and runs at another breaks serial timing rather than a delay loop; ATmega1280V program recovery covers that case.

FAQ

Will a 5 V programmer damage an ATtiny45V? It can, and it can also damage everything else sharing the rail. Separating the supplies is the fix, not lowering the programmer’s current limit.

Why does the signature read as all zeros? All zeros is what a programmer reports when it receives no valid response, which points at levels or clock rather than at protection.

Can the interface clock be raised after the first successful read? Yes. Once the read works, speed is a convenience. Before it works, speed is the variable to reduce.

Conclusion

Two numbers decide whether a low-voltage part can be read at all: the voltage the programmer presents and the rate at which it toggles the interface clock. Neither is visible in the failure, which is why the failure is so often attributed to the lock bits. Set the levels to the target’s rail, drop the interface clock below a quarter of the target’s clock, and most «dead» V parts answer normally.

The PALCE16V8H-15JC is a classic programmable logic device (PLD) widely adopted in legacy digital systems where fast combinational logic, deterministic timing, and compact design are required. It has been extensively used in industrial controllers, telecommunications interfaces, instrumentation equipment, automotive subsystems, and embedded control boards. Unlike microcontrollers that rely on sequential firmware execution, this PLD implements hardware-defined logic through programmed fuse maps, allowing stable and predictable operation. However, when the original design archive, logic file, or source code is missing, maintaining or reproducing such systems becomes extremely challenging. The Break PLD PALCE16V8H-15JC Software service is designed to help authorized users recover and reconstruct this critical embedded logic data from secured devices.

In many deployed systems, the PALCE16V8H-15JC is configured with protective, protected, locked, or secured fuse settings that prevent access to its internal memory and configuration data. These mechanisms ensure that the PLD’s programmed logic—stored in binary or heximal fuse maps—cannot be directly read out. Our service focuses on helping clients attack, break, or carefully decode these restrictions through advanced engineering analysis. By studying the embedded structure of the PLD, we can retrieve logic configuration data, reconstruct the internal program, and rebuild a usable archive even when the device is fully protected. In complex cases, controlled decapsulate approaches may be applied to access deeply embedded fuse structures, enabling extraction of configuration patterns from otherwise inaccessible regions. The process ensures that recovered binary or heximal data accurately reflects the original programmed logic without compromising reliability.

We can Break PLD PALCE16V8H-15JC Software, please view below PLD PALCE16V8H-15JC features for your reference:

DISTINCTIVE CHARACTERISTICS

Pin and function compatible with all 20-pin GAL devices

Electrically erasable CMOS technology provides reconfigurable logic and full testability

High-speed CMOS technology

— 5-ns propagation delay for “-5” version

— 7.5-ns propagation delay for “-7” version

Direct plug-in replacement for the PAL16R8 series and most of the PAL10H8 series

Outputs programmable as registered or combinatorial in any combination, Peripheral Component Interconnect (PCI) compliant.

GENERAL DESCRIPTION

The PALCE16V8 is an advanced PAL device built with low-power, high-speed, electrically-erasable CMOS technology. It is functionally compatible with all 20-pin GAL devices. The macrocells provide a universal device architecture. The PALCE16V8 will directly replace the PAL16R8 and PAL10H8 series devices, with the exception of the PAL16C1.

The PALCE16V8 utilizes the familiar sum-of-products (AND/OR) architecture that allows users to implement complex logic functions easily and efficiently. Multiple levels of combinatorial logic can always be reduced to sum-of-products form, taking advantage of the very wide input gates available in PAL devices. The equations are programmed into the device through floating gate cells in the AND logic array that can be erased electrically.

Programmable output polarity

Programmable enable/disable control

Preloadable output registers for testability

Automatic register reset on power up

Cost-effective 20-pin plastic DIP, PLCC, and SOIC packages

Extensive third-party software and programmer support through FusionPLD partners

Fully tested for 100% programming and functional yields and high reliability

5 ns version utilizes a split leadframe for improved performance.

The fixed OR array allows up to eight data product terms per output for logic functions. The sum of these products feeds the output macrocell. Each macrocell can be programmed as registered or combinatorial with an active high or active-low output. The output configuration is determined by two global bits and one local bit controlling four multiplexers in each macrocell. AMD’s FusionPLD program allows PALCE16V8 designs to be implemented using a wide variety of popular industry-standard design tools. By working closely with the FusionPLD partners, AMD certifies that the tools provide accurate, quality support. By ensuring that third party tools are available, costs are lowered because a designer does not have to buy a complete set of new tools for each device. The Fusion PLD program also greatly reduces design time since a designer can use a tool that is already installed and familiar.

Once the configuration data is successfully retrieved, it must be translated into a meaningful representation for engineering use. The extracted binary fuse map is decoded into logical equations or equivalent structures, allowing partial or full reconstruction of the original source code or design intent. This enables clients to clone or duplicate the PLD functionality on compatible devices or migrate the design into modern programmable platforms such as CPLDs or FPGAs. Even though the PALCE16V8H-15JC does not store traditional firmware, its programmed logic serves as a functional equivalent of an embedded program, and recovering this information is essential for system continuity.

For manufacturers, system integrators, and maintenance providers, the Break PLD PALCE16V8H-15JC Software service offers significant practical benefits. It allows legacy equipment to remain operational, avoids costly redesign efforts, and preserves valuable embedded logic that may no longer be documented. Instead of replacing entire systems due to locked or encrypted PLD devices, organizations can regain access to their configuration data, logic program, and design archive. By combining deep expertise in programmable logic devices with careful handling of protected and secured environments, this service provides a reliable pathway to recover, reuse, and extend critical embedded system functionality across a wide range of industries.