The R5F100EF is the 96 KB member of the 40-pin row, crossing the family’s
data-flash boundary into the 8 KB array while keeping the nine-channel
converter and the 6 by 6 mm HWQFN. It pairs a large program store with the
biggest volatile memory budget the sub-128 KB members carry, and it is the
capacity at which logging-heavy appliance firmware becomes the norm rather
than the exception.

The 8 KB data flash at this capacity

From 96 KB upward the separate data array is 8 KB instead of 4 KB, and the
doubling changes what firmware does with it: long fault histories,
calibration generations and usage logs that a smaller member could not
afford. For recovery work the array is the most evidence-dense region of the
chip, read with the data-flash command set and captured with its own
protection flags. The wear-levelled structure inside it dates the unit’s
service life and often explains the fault that brought the board in.

Ninety-six blocks and the update zone

The code array divides into ninety-six one-kilobyte blocks with the boot
cluster in the first four and the swap target at 02000H. Images this size
are field-updated routinely, so both clusters are populated and the boot
flag in block 0 picks the live generation. The inactive cluster holds the
firmware the product shipped with, and the standard capture takes both plus
the flag and the option block.

Eight KB of RAM as working space

The volatile memory hosts the flash library, the update protocol and the
application’s live state simultaneously, and the self-RAM reservation in a
recovered linker map marks the image as update-capable. In-circuit capture
is comfortable on this member: the sequencer’s idle time serves the read
path, verification is per block, and the loader coexists with the running
application without squeezing it.

Protection at this capacity

The option bytes at 000C0H to 000C3H, the ten-byte identifiers at 000C4H and
000CEH, and the shipped block protections including the boot-area guard are
family-standard. The shield window, where firmware uses it, confines updates
to the blocks the protocol touches, and all of the security configuration is
recorded during capture so a repaired image can be written back with the
original posture intact.

The QFN bench

The 0.5 mm wings and bonded pad set the access order: layout test features,
fixture, lift-and-reball, and the die through IC decapsulation service as the last
resort. The single-wire TOOL0 pad on P40 is the pin worth finding on any
layout, because the serial path it opens authenticates with the ten-byte
identifier rather than risking the debug path’s destructive bit.

Row context

The 40-pin siblings are in R5F100EA program memory through R5F100EE flash data and
R5F100EG code flash extraction and R5F100EH firmware decryption. The 96 KB die in other packages is the
30-pin R5F100AF memory readout, the 32-pin R5F100BF memory dump, the 36-ball
R5F100CF locked flash and the 44-pin R5F100FF embedded memory. For the data-flash boundary
itself and what the doubling means, the 36-ball note at R5F100CF locked flash
covers it, and the family workflow is on the MCU crack service page.

Vector reconstruction at 96 KB

A capture at this capacity is large enough that the vector table earns
its own pass. The bottom of the array lists the reset and exception
entry points, and the handler code behind them reveals how the two
transfer engines were divided, how the watchdog was serviced and which
converter channels the firmware actually sampled. For a repair, the
table is the map of what must not move; for an analysis, it is the
fastest inventory of what the product does. Either way the first
kilobyte, which also carries the security bytes and the boot flag, gets
read and archived before anything else in the job proceeds.

The doubled 8 KB data store completes the picture with its fault and
usage records, read under its own command set with its protection flags
noted. Captures that skip it have a predictable failure mode: the
rebuilt controller boots, runs and misregulates, and the missing scaling
factors are discovered only after the customer has installed the board.

Reconstructing the vector table early also settles a repair question: which entry points may move during a patch and which are pinned by the boot ROM’s expectations.