Break IC, Recover MCU, Microcontroller Reverse Engineering

We can duplicate avr microprocessor ATMEGA8PA protected firmware, please view the avr microprocessor ATMEGA8PA features for your reference:

The ATMEGA8PA devices are offered with Internal Oscillator mode only when duplicate avr microprocessor ATMEGA8PA.
· INTOSC: Internal 4 MHz Oscillator
The internal oscillator provides a 4 MHz (nominal) system clock (see Section 12.0 “Electrical Characteristics” for information on variation over voltage and temperature).
In addition, a calibration instruction is programmed into the last address of memory, which contains the calibration value for the internal oscillator.
This location is always uncode protected, regardless of the code-protect settings. This value is programmed as a MOVLW xx instruction where xx is the calibration value and is placed at the Reset vector if Duplicate AVR Microprocessor ATmega8PA Protected Firmware.
This will load the W register with the calibration value upon Reset and the PC will then roll over to the users program at address 0x000.
The user then has the option of writing the value to the OSCCAL Register (05h) or ignoring it. OSCCAL, when written to with the calibration value, will “trim” the internal oscillator to remove process variation from the oscillator frequency.
The device differentiates between various kinds of Reset:
· Power-on Reset (POR)
· MCLR Reset during normal operation
· MCLR Reset during Sleep
· WDT time-out Reset during normal operation
· WDT time-out Reset during Sleep
Wake-up from Sleep on pin change
Wake-up from Sleep on comparator change if Duplicate AVR Microprocessor ATmega8PA Protected Firmware
Some registers are not reset in any way, they are unknown on POR and unchanged in any other Reset.
Most other registers are reset to “Reset state” on Power-on Reset (POR), MCLR, WDT or Wake-up on pin change Reset during normal operation. They are not affected by a WDT Reset during Sleep or MCLR Reset during Sleep, since these Resets are viewed as resumption of normal operation.
The exceptions to this are TO, PD, GPWUF and CWUF bits. They are set or cleared differently in different Reset situations. These bits are used in software to determine the nature of Reset.
See Table 9-1 for a full description of Reset states of all registers if BREAK IC.

We can read atmel IC ATMEGA16A locked code, please view the atmel IC ATMEGA16A features for your reference:
The atmel IC ATMEGA16A devices incorporate an on-chip Power-on Reset (POR) circuitry, which provides an internal chip Reset for most power-up situations.
The on-chip POR circuit holds the chip in Reset until VDD has reached a high enough level for proper operation. To take advantage of the internal POR, program the GP3/MCLR/VPP pin as MCLR and tie through a resistor to VDD, or program the pin as GP3.
An internal weak pull-up resistor is implemented using a transistor (refer to Table 12-2 for the pull-up resistor ranges). This will eliminate external RC components usually needed to create a Power-on Reset. A maximum rise time for VDD is specified.
See Section 12.0 “Electrical Characteristics” for details. When the devices start normal operation (exit the Reset condition), device operating parameters (voltage, frequency, temperature,…) must be met to ensure operation after Read Atmel IC ATmega16A Locked Code.
If these conditions are not met, the devices must be held in Reset until the operating parameters are met. A simplified block diagram of the on-chip Power-on Reset circuit. The Power-on Reset circuit and the Device Reset Timer (see Section 9.5 “Device Reset Timer (DRT)”) circuit are closely related. On power-up, the Reset latch is set and the DRT is reset. The DRT timer begins counting once it detects MCLR to be high.
After the time-out period, which is typically 18 ms, it will reset the Reset latch and thus end the on-chip Reset signal. A power-up example where MCLR is held low is shown in Figure 9-3. VDD is allowed to rise and stabilize before bringing MCLR high.
The chip will actually come out of Reset TDRT msec after MCLR goes high. In Figure 9-4, the on-chip Power-on Reset feature is being used (MCLR and VDD are tied together or the pin is programmed to be GP3) when Read Atmel IC ATmega16A Locked Code.
The VDD is stable before the Start-up Timer times out and there is no problem in getting a proper Reset. However, Figure 9-5 depicts a problem situation where VDD rises too slowly. The time between when the DRT senses that MCLR is high and when MCLR and VDD actually reach their full value, is too long. In this situation, when the Start-up Timer times out, VDD has not reached the VDD (min) value and the chip may not function correctly. For such situations, we recommend that external RC circuits be used to achieve longer POR delay times if RECOVER MCU.

We can extract atmel microprocessor ATMEGA16PA firmware, please view the atmel microprocessor ATMEGA16PA features for your reference:
The TO, PD, GPWUF and CWUF bits in the STATUS register can be tested to determine if a Reset condition has been caused by a power-up condition, a MCLR, Watchdog Timer (WDT) Reset, wake-up on comparator change or wake-up on pin change.
A Brown-out Reset is a condition where device power (VDD) dips below its minimum value, but not to zero, and then recovers. The device should be reset in the event of a brown-out when extract atmel microprocessor.
To reset ATmega16pa devices when a Brown-out Reset occurs, external brown-out protection circuits may be built if Extract Atmel Microprocessor ATmega16PA Firmware.
A device may be powered down (Sleep) and later powered up (wake-up from Sleep). The Power-Down mode is entered by executing a SLEEP instruction.

If enabled, the Watchdog Timer will be cleared but keeps running, the TO bit (STATUS<4>) is set, the PD bit (STATUS<3>) is cleared and the oscillator driver is turned off after extract atmel microprocessor.
The I/O ports maintain the status they had before the SLEEP instruction was executed (driving high, driving low or high-impedance).

For lowest current consumption while powered down, the T0CKI input should be at VDD or VSS and the GP3/ MCLR/VPP pin must be at a logic high level if MCLR is enabled.
The device can wake-up from Sleep through one of the following events:
An external Reset input on GP3/MCLR/VPP pin, when configured as MCLR.
A Watchdog Timer time-out Reset (if WDT was enabled).
A change on input pin GP0, GP1 or GP3 when wake-up on change is enabled.

A comparator output change has occurred when wake-up on comparator change is enabled when Extract Atmel Microprocessor ATmega16PA Firmware.

These events cause a device Reset. The TO, PD GPWUF and CWUF bits can be used to determine the cause of device Reset. The TO bit is cleared if a WDT time-out occurred (and caused wake-up) if extract atmel microprocessor.
The PD bit, which is set on power-up, is cleared when SLEEP is invoked. The GPWUF bit indicates a change in state while in Sleep at pins GP0, GP1 or GP3 (since the last file or bit operation on GP port) after EXTRACT IC.

The CWUF bit indicates a change in the state while in Sleep of the comparator output.

We can recover avr microcontroller ATMEGA32PA program, please view the avr microcontroller ATMEGA32PA features for your reference:
If the code protection bit has not been programmed, the on-chip program memory can be read out for verification purpose, The first 64 locations and the last location (Reset vector) can be read, regardless of the code protection bit setting.
Four memory locations are designated as ID locations where the user can store checksum or other code identification numbers. These locations are not accessible during normal execution, but are readable and writable during Program/Verify.
Use only the lower 4 bits of the ID locations and always program the upper 8 bits as ‘0’s. The avr microcontroller ATMEGA32PA microcontrollers can be serially programmed while in the end application circuit before Recover AVR Microcontroller ATmega32PA Program.
This is simply done with two lines for clock and data, and three other lines for power, ground and the programming voltage. This allows customers to manufacture boards with unprogrammed devices and then program the microcontroller just before shipping the product. This also allows the most recent firmware or a custom firmware, to be programmed.
The devices are placed into a Program/Verify mode by holding the GP1 and GP0 pins low while raising the MCLR (VPP) pin from VIL to VIHH (see programming specification). GP1 becomes the programming clock and GP0 becomes the programming data. Both GP1 and GP0 are Schmitt Trigger inputs in this mode.
After Reset, a 6-bit command is then supplied to the device. Depending on the command, 16 bits of program data are then supplied to or from the device, depending if the command was a Load or a Read. For complete details of serial programming, please refer to the avr microcontroller ATMEGA32PA Programming Specifications. A typical In-Circuit Serial Programming connection is shown in Figure 9-10 after Recover AVR Microcontroller ATmega32PA Program.
The PIC16 instruction set is highly orthogonal and is comprised of three basic categories.
· Byte-oriented operations
· Bit-oriented operations
· Literal and control operations
Each PIC16 instruction is a 12-bit word divided into an opcode, which specifies the instruction type and one or more operands which further specify the operation of the instruction. The formats for each of the categories is presented in Figure 10-1, while the various opcode fields are summarized in Table 10-1.
For byte-oriented instructions, ‘f’ represents a file register designator and ‘d’ represents a destination designator. The file register designator specifies which file register is to be used by the instruction if recover avr microcontroller.
The destination designator specifies where the result of the operation is to be placed. If ‘d’ is ‘0’, the result is placed in the W register. If ‘d’ is ‘1’, the result is placed in the file register specified in the instruction before Recover AVR Microcontroller ATmega32PA Program.
For bit-oriented instructions, ‘b’ represents a bit field designator which selects the number of the bit affected by the operation, while ‘f’ represents the number of the file in which the bit is located. All instructions are executed within a single instruction cycle, unless a conditional test is true or the program counter is changed as a result of an instruction. In this case, the execution takes two instruction cycles. One instruction cycle consists of four oscillator periods.
Thus, for an oscillator frequency of 4 MHz, the normal instruction execution time is 1 ìs. If a conditional test is true or the program counter is changed as a result of an instruction, the instruction execution time is 2. Figure 10-1 shows the three general formats that the instructions can have. All examples in the figure use the following format to represent a hexadecimal number from RECOVER MCU.

We can reverse engineering ATMEL AVR Chip ATMEGA32A program file, please view the ATMEL AVR Chip ATMEGA32A features for your reference:
The 9th bit of the program counter will be forced to a ‘0’ by any instruction that writes to the PC except for GOTO. See Section 4.7 “Program Counter”. When an I/O register is modified as a function of itself (e.g. MOVF PORTB, 1), the value used will be that value present on the pins themselves. For example, if the data latch is ‘1’ for a pin configured as input and is driven low by an external device, the data will be written back with a ‘0’.
The instruction TRIS f, where f = 6, causes the contents of the W register to be written to the tri-state latches of PORTB. A ‘1’ forces the pin to a high-impedance state and disables the output buffers.
If this instruction is executed on the TMR0 register (and where applicable, d = 1), the prescaler will be cleared (if assigned to TMR0).
The PIC® ATMEL AVR Chips are supported with a full range of hardware and software development tools:
· Integrated Development Environment after Reverse Engineering ATMEL AVR Chip ATmega32A Program File.
– MPLAB® IDE Software
· Assemblers/Compilers/Linkers
– MPASMTM Assembler
– MPLAB C18 and MPLAB C30 C Compilers
– MPLINKTM Object Linker/MPLIBTM Object Librarian
– MPLAB ASM30 Assembler/Linker/Library
· Simulators
– MPLAB SIM Software Simulator
· Emulators
– MPLAB ICE 2000 In-Circuit Emulator
– MPLAB ICE 4000 In-Circuit Emulator
· In-Circuit Debugger
– MPLAB ICD 2
· Device Programmers
– PICSTART® Plus Development Programmer
– MPLAB PM3 Device Programmer
– PICkit™ 2 Development Programmer
· Low-Cost Demonstration and Development Boards and Evaluation Kits
The MPLAB IDE software brings an ease of software development previously unseen in the 8/16-bit ATMEL AVR Chip market. The MPLAB IDE is a Windows® operating system-based application that contains:
· A single graphical interface to all debugging tools after Reverse Engineering ATMEL AVR Chip ATmega32A Program File
– Simulator
– Programmer (sold separately)
– Emulator (sold separately)
– In-Circuit Debugger (sold separately)
· A full-featured editor with color-coded context
· A multiple project manager
· Customizable data windows with direct edit of contents
· High-level source code debugging
· Visual device initializer for easy register initialization
· Mouse over variable inspection
· Drag and drop variables from source to watch windows
· Extensive on-line help
· Integration of select third party tools, such as
HI-TECH Software C Compilers and IAR C Compilers
The MPLAB IDE allows you to:
· Edit your source files (either assembly or C)
· One touch assemble (or compile) and download to PIC MCU emulator and simulator tools (automatically updates all project information)
· Debug using:
– Source files (assembly or C)
– Mixed assembly and C
– Machine code
MPLAB IDE supports multiple debugging tools in a single development paradigm, from the cost-effective simulators, through low-cost in-circuit debuggers, to full-featured emulators. This eliminates the learning curve when upgrading to tools with increased flexibility and power when Reverse Engineering Microcontroller.

We can replicate Atmel AVR controller ATMEGA168P eeprom code, please view the Atmel AVR controller ATMEGA168P features for your reference:
This Configuration bit, when unprogrammed (left in the ‘1’ state), enables the external MCLR function. When programmed, the MCLR function is tied to the internal VDD and the pin is assigned to be a I/O..
The ATMEGA168P devices incorporate an on-chip Power-on Reset (POR) circuitry, which provides an internal chip Reset for most power-up situations.
The on-chip POR circuit holds the chip in Reset until VDD has reached a high enough level for proper operation. To take advantage of the internal POR, program the GP3/MCLR/VPP pin as MCLR and tie through a resistor to VDD, or program the pin as GP3.
An internal weak pull-up resistor is implemented using a transistor (refer to Table 12-2 for the pull-up resistor ranges). This will eliminate external RC components usually needed to create a Power-on Reset before replicate Atmel AVR controller ATMEGA168P eeprom code.
A maximum rise time for VDD is specified. See Section 12.0 “Electrical Characteristics” for details. When the devices start normal operation (exit the Reset condition), device operating parameters (voltage, frequency, temperature,…) must be met to ensure operation.
If these conditions are not met, the devices must be held in Reset until the operating parameters are met. A simplified block diagram of the on-chip Power-on Reset circuit. The Power-on Reset circuit and the Device Reset Timer (see Section 9.5 “Device Reset Timer (DRT)”) circuit are closely related. On power-up, the Reset latch is set and the DRT is reset. The DRT timer begins counting once it detects MCLR to be high if replicate Atmel AVR controller ATMEGA168P eeprom code.
After the time-out period, which is typically 18 ms, it will reset the Reset latch and thus end the on-chip Reset signal. A power-up example where MCLR is held low is shown in Figure 9-3. VDD is allowed to rise and stabilize before bringing MCLR high.
The chip will actually come out of Reset TDRT msec after MCLR goes high. In Figure 9-4, the on-chip Power-on Reset feature is being used (MCLR and VDD are tied together or the pin is programmed to be GP3).
The VDD is stable before the Start-up Timer times out and there is no problem in getting a proper Reset. However, Figure 9-5 depicts a problem situation where VDD rises too slowly.
The time between when the DRT senses that MCLR is high and when MCLR and VDD actually reach their full value, is too long. In this situation, when the Start-up Timer times out, VDD has not reached the VDD (min) value and the chip may not function correctly when replicate Atmel AVR controller ATMEGA168P eeprom code.
For such situations, we recommend that external RC circuits be used to achieve longer POR delay times.

We can decapsulate atmel avr IC ATMEGA168PV flash code, please view the IC ATMEGA168PV features for your reference:
On the ATMEGA168PV devices, the DRT runs any time the device is powered up. The DRT operates on an internal oscillator. The processor is kept in Reset as long as the DRT is active. The DRT delay allows VDD to rise above VDD min. and for the oscillator to stabilize.
The on-chip DRT keeps the devices in a Reset condition for approximately 18 ms after MCLR has reached a logic high (VIH MCLR) level before Decapsulate Atmel AVR IC ATmega168PV Flash Code.
Programming GP3/MCLR/VPP as MCLR and using an external RC network connected to the MCLR input is not required in most cases. This allows savings in cost-sensitive and/or space restricted applications, as well as allowing the use of the GP3/MCLR/VPP pin as a general purpose input.
The Device Reset Time delays will vary from chip-to-chip due to VDD, temperature and process variation. See AC parameters for details if Decapsulate Atmel AVR IC ATmega168PV Flash Code.
Reset sources are POR, MCLR, WDT time-out and wake-up on pin change. The Watchdog Timer (WDT) is a free running on-chip RC oscillator, which does not require any external components. This RC oscillator is separate from the internal 4 MHz oscillator.
This means that the WDT will run even if the main processor clock has been stopped, for example, by execution of a SLEEP instruction. During normal operation or Sleep, a WDT Reset or wake-up Reset, generates a device Reset. The TO bit (STATUS<4>) will be cleared upon a Watchdog Timer Reset.
The WDT can be permanently disabled by programming the configuration WDTE as a ‘0’ (see Section 9.1 “Configuration Bits”). Refer to the ATMEGA168PV Programming Specifications to determine how to access the Configuration Word after BREAK IC.

We can decode Atmel AVR processor ATMEGA169P locked code, please view the Atmel AVR processor ATMEGA169P features for your reference:
The TO, PD, GPWUF and CWUF bits in the STATUS register can be tested to determine if a Reset condition has been caused by a power-up condition, a MCLR, Watchdog Timer (WDT) Reset, wake-up on comparator change or wake-up on pin change.
A Brown-out Reset is a condition where device power (VDD) dips below its minimum value, but not to zero, and then recovers. The device should be reset in the event of a brown out.
A device may be powered down (Sleep) and later powered up (wake-up from Sleep). The Power-Down mode is entered by executing a SLEEP instruction before Decode Atmel AVR Processor ATMEGA169P Locked Code.
If enabled, the Watchdog Timer will be cleared but keeps running, the TO bit (STATUS<4>) is set, the PD bit (STATUS<3>) is cleared and the oscillator driver is turned off.
The I/O ports maintain the status they had before the SLEEP instruction was executed (driving high, driving low or high-impedance).
For lowest current consumption while powered down, the T0CKI input should be at VDD or VSS and the GP3/MCLR/VPP pin must be at a logic high level if MCLR is enabled.
The device can wake-up from Sleep through one of the following events:
An external Reset input on GP3/MCLR/VPP pin, when configured as MCLR. A Watchdog Timer time-out Reset (if WDT was enabled) before Decode Atmel AVR Processor ATMEGA169P Locked Code.
A change on input pin GP0, GP1 or GP3 when wake-up on change is enabled. wake-up on change is enabled. A comparator output change has occurred when wake-up on comparator change is enabled.
These events cause a device Reset. The TO, PD GPWUF and CWUF bits can be used to determine the cause of device Reset. The TO bit is cleared if a WDT time-out occurred (and caused wake-up).
The PD bit, which is set on power-up, is cleared when SLEEP is invoked. The GPWUF bit indicates a change in state while in Sleep at pins GP0, GP1 or GP3 (since the last file or bit operation on GP port) when Decode Atmel AVR Processor ATMEGA169P Locked Code.
The CWUF bit indicates a change in the state while in Sleep of the comparator output.

We can restore avr controller ATTINY24 encrypted heximal, please view the avr controller ATTINY24 features for your reference:
If the code protection bit has not been encrypted HEX, the on-chip encrypted heximal memory can be read out for verification purposes.
The first 64 locations and the last location (Reset vector) can be read, regardless of the code protection bit setting.
Four memory locations are designated as ID locations where the user can store checksum or other code identification numbers. These locations are not accessible during normal execution, but are readable and writable during Restore AVR Controller ATtiny24 Encrypted Heximal.
Use only the lower 4 bits of the ID locations and always encrypted heximal the upper 8 bits as ‘0’s. The ATTINY24 microcontrollers can be serially encrypted heximalmed while in the end application circuit.
This is simply done with two lines for clock and data, and three other lines for power, ground and the encrypted heximalming voltage. This allows customers to manufacture boards with unencrypted heximalmed devices and then encrypted heximal the microcontroller just before shipping the product.
This also allows the most recent firmware or a custom firmware, to be encrypted heximalmed. The devices are placed into a encrypted heximal/Verify mode by holding the GP1 and GP0 pins low while raising the MCLR (VPP) pin from VIL to VIHH (see encrypted heximalming specification) if Restore AVR Controller ATtiny24 Encrypted Heximal.
GP1 becomes the encrypted heximalming clock and GP0 becomes the encrypted heximalming data. Both GP1 and GP0 are Schmitt Trigger inputs in this mode. After Reset, a 6-bit command is then supplied to the device.
Depending on the command, 16 bits of encrypted heximal data are then supplied to or from the device, depending if the command was a Load or a Read. For complete details of serial encrypted heximalming, please refer to the ATTINY24 encrypted heximalming Specifications after RECOVER MCU.

We can break Protected AVR Chip ATTINY24V firmware, please view the Protected AVR Chip ATTINY24V features for your reference:
The ATTINY24V instruction set is highly orthogonal and is comprised of three basic categories.
· Byte-oriented operations
· Bit-oriented operations
· Literal and control operations
Each PIC16 instruction is a 12-bit word divided into an opcode, which specifies the instruction type and one or more operands which further specify the operation of the instruction.
The formats for each of the categories is presented in Figure 10-1, while the various opcode fields are summarized in Table 10-1 before Break Protected AVR Chip ATTINY24V Firmware.
For byte-oriented instructions, ‘f’ represents a file register designator and ‘d’ represents a destination designator. The file register designator specifies which file register is to be used by the instruction.
The destination designator specifies where the result of the operation is to be placed. If ‘d’ is ‘0’, the result is placed in the W register. If ‘d’ is ‘1’, the result is placed in the file register specified in the instruction.
For bit-oriented instructions, ‘b’ represents a bit field designator which selects the number of the bit affected by the operation, while ‘f’ represents the number of the file in which the bit is located if Break Protected AVR Chip ATTINY24V Firmware.
For literal and control operations, ‘k’ represents an 8 or 9-bit constant or literal value.
All instructions are executed within a single instruction cycle, unless a conditional test is true or the firmware counter is changed as a result of an instruction. In this case, the execution takes two instruction cycles.
One instruction cycle consists of four oscillator periods. Thus, for an oscillator frequency of 4 MHz, the normal instruction execution time is 1 ìs. If a conditional test is true or the firmware counter is changed as a result of an instruction, the instruction execution time is 2 ìs when Break Protected AVR Chip ATTINY24V Firmware.
Figure 10-1 shows the three general formats that the instructions can have. All examples in the figure use the following format to represent a hexadecimal number: 0xhhh where ‘h’ signifies a hexadecimal digit after Break IC.