The R5F100GF moves the 48-pin row across the data-flash boundary of the
family: 96 KB of code flash, 8 KB of RAM and, for the first time in this
package, the doubled 8 KB data array, all in the 7 by 7 mm LFQFP on a
0.5 mm pitch with ten converter inputs and forty-four I/O. Designs that
outgrow the 64 KB members usually land here, and the combination of a
mid-industrial program store with a doubled log space is what makes the part
routine on compressor drives, charger controllers and communication
gateways.

Ninety-six blocks and a duplicated floor

The program array divides into ninety-six erase blocks of one kilobyte. The
lowest four form the boot region, and the four starting at 02000H hold its
mirror for designs that update in the field; when the swap mechanism is
active the security configuration is written twice, once per copy, and a
flag in the first block names the live one. On a board with any update
history the inactive copy still contains the firmware generation the product
shipped with, and reading it costs nothing extra: the same pass that walks
the live half walks the mirror.

The doubled data array as a service record

From this capacity upward the separate data store is 8 KB, organised in its
own small blocks with independent protection flags. Appliance and industrial
firmware use the room aggressively: rotating fault logs, per-cycle energy
counters, calibration revisions stamped with run hours. Reconstructing a
unit’s biography from that log is often possible to the hour, and a
controller rebuilt without it loses the accumulated factors that make
regulation match the original. The array is read with its own command set
during the same session as the code, and its protection flags are recorded
with the security state.

Eight kilobytes of working memory

The 8 KB of volatile memory is enough for the flash library, an update
protocol and the application’s buffers to coexist, which is why images at
this capacity are almost always update-capable. The library reserves its
workspace from the top of RAM, and the reservation is visible in any
recovered linker map. For a readout the same region is the natural home of a
streaming loader: the sequencer suspends code fetch while it works, so the
walker in RAM keeps streaming blocks while the array is otherwise idle, and
a marginal fixture contact surfaces as one failed kilobyte instead of a
corrupt capture.

Security configuration in practice

Four bytes at the bottom of the first block set watchdog, detector and
oscillator policy, and the last of the four additionally decides whether the
debug interface answers at all and what a wrong identifier costs, up to and
including the whole array. Two independent ten-byte secrets follow, one for
the emulator and one for the serial programmer that talks over TOOL0. A
blank pair is common on cost-driven boards; a half-written pair, one secret
present and its twin forgotten, is the single most useful finding a first
session can produce, because it usually leaves exactly one working route
into the image.

The readout, end to end

A complete job captures the live and mirror code halves, the 8 KB data
array, the security bytes as found and the boot flag, verifies per block,
and records the option-byte state so a written-back repair restores the
original posture. Where every electrical route is closed the package still
cooperates: the part lifts, re-balls onto an adapter and presents the serial
wire directly, and only a damaged die sends the job to the physical layer.
The imaging workflow is on the firmware extraction service page, and die-level work is the
IC decapsulation service route.

Neighbours in the row and the family

The row starts at R5F100GA memory readout and steps up through R5F100GG memory dump toward
the half-megabyte top. The same 96 KB die appears as the 30-pin
R5F100AF memory readout, the 36-ball R5F100CF locked flash and the 44-pin R5F100FF embedded memory,
the nearest references for planning a capture in another package. The
MCU crack service page carries the family-level workflow.

A note on the RAM class

Eight kilobytes is the first size where the update machinery, the
protocol and the application coexist without engineering effort, and
that fact, more than any single feature, is why images at this capacity
are the family’s most consistently update-capable. The reservation in
the linker map is the visible proof.