When the data store is a separate chip, finding it is not a problem: it has a part number, a bus, and an address that the processor writes to. When the store is a region of the application flash, none of that holds. There is no component, no address that announces itself, and no header saying this is where the settings begin.

Everything about the extraction depends on locating that region first, and locating it is the part of the job that most recoveries do by guesswork. Guesswork fails in a specific way: the decoded table looks plausible, the customer compares one value against the machine’s display, finds it wrong, and the whole delivery loses credibility.

R5F562T7ADFF#V3 is one of the larger-memory order codes in the RX62T group. Its peripheral set — two twelve-bit converter units, a six-channel timer, an output-enable block — is the motor-control configuration, and motor-control products are exactly the products that keep calibration offsets, current limits and fault counters in a persistent store.

Five markers, in the order that works

Work them in that order. The first four are arithmetic and pattern matching, and they narrow the search to a handful of candidates before any disassembly is required.

The erased run is the strongest signal

A flash image is mostly written. An erased run of a kilobyte or more, somewhere in the middle of the map rather than at the end of the used region, is nearly always a data area that has not been filled yet, or a block reserved for one.

Its position relative to block boundaries is the second half of the signal. Data areas are almost always block aligned, because a design that intends to erase and rewrite them has to respect the erase granularity. A candidate region that starts mid-block is a coincidence; one that starts exactly on a block edge is a decision.

Two candidates that both look like erased runs can be separated by their size: a reserved parameter block will be a whole number of blocks, while a gap left by the linker will be whatever alignment required, which is usually much smaller.

Periodicity and strings

If the design keeps records, the region shows a period: the same distance between entries, repeated. That period is the record length, and finding it is most of the work, because once the stride is known the fields become visible as columns.

Periodicity is visible even in a hexdump, and it is trivially visible in a small script that correlates the region with itself at every offset and reports the offsets with high agreement. An offset that produces a strong correlation is the record length or a multiple of it.

Strings are the free win. A parameter name, a unit suffix, a fault description stored next to the value it describes — any of these turns a structural guess into a certain identification. Designs that keep a fault log frequently keep human-readable text with it, because the text eventually reaches a service display.

The code cross-reference, and where it lies

The fifth marker is the authoritative one: a literal in the code that holds the region’s base address. Compilers emit these as immediate values or as entries in a literal pool, and a search for a four-byte value equal to the candidate address, in either byte order, finds them quickly.

Two cautions. The address may be computed rather than loaded — a base plus a fixed offset — so search for the base and for the base plus plausible offsets. And on a design with a memory protection unit or a relocatable region, the literal may be an offset rather than an absolute address, which makes this marker useless and sends you back to the first four.

Why the last block is a convention

Designs habitually place the parameter area in the highest block of the flash, or in the last block of a reserved region below the option bytes. Three reasons, all practical: it keeps the parameter area out of the way of code growth, it makes the linker script simple, and it survives a firmware update that rewrites the low blocks.

So the first place to look is the top, just below the vector and option regions. The second place is the block after the last used code block, which is where a design that grew organically tends to have put it.

When neither location holds anything, the store is probably not in the processor at all, and the search should move to the board.

Reporting the location, not just the values

A delivery that states values without stating where they came from is impossible to verify and impossible to extend.

What makes it verifiable is the evidence chain: the address range, the record stride, the field offsets within a record, and the one marker that identified the region. With those four facts, a second unit from the same product can be decoded in ten minutes by somebody who was not involved.

That is the difference between a recovery and a favour, and it is also what makes an EEPROM request repeatable as a service rather than as a one-off.

For the record format once the region is found, R5F562TABDFF EEPROM covers the log structure. For the three possible arrangements behind the word, R5F562TAEDFF EEPROM sets out the decision tree. And for a unit that will not boot at all, R5F562TAADFH EEPROM covers the dead-board route.

FAQ

Can the store be found without the firmware? Usually. Four of the five markers are structural, and the fifth only confirms what the others suggested.

What if the design keeps no record structure? Then the region is a fixed table with fixed offsets, which is easier: the values line up in columns and the offsets are constant.

Is it ever a separate chip? Yes, often on designs that needed frequent writes. Look for serial-channel initialisation before concluding that the store is internal.

The short version

Find the region before decoding it. An erased run on a block boundary is the strongest signal, periodicity gives the record length, strings confirm it, and a literal in the code settles it. Then report the address range and the stride alongside the values, because the next unit will need them.

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