The R5F100AF is the point where the 30-pin row crosses into the large-memory
configuration: 96 KB of code flash with 8 KB of RAM and, for the first time in
the row, an 8 KB data flash array instead of 4 KB. The LSSOP package with
0.65 mm pins is unchanged, the converter is still eight channels, but the
memory boundary at 64 KB that separated the small-data-flash members from the
large ones sits just below this part, and several practical consequences
follow from being on the far side of it.

The 8 KB data flash boundary

Renesas fits a 4 KB data flash to every member up to 64 KB of code flash and
an 8 KB array from 96 KB upward. The change doubles the EEPROM-emulation
capacity that firmware can count on and moves the wear-levelled structure
into a size where logging real history becomes routine rather than a
compromise. For recovery work the larger array carries proportionally more
evidence: usage counters, fault records and calibration generations that a 4
KB part could not have afforded. Capturing it is not an optional extra on
this member.

Ninety-six blocks and eight KB of RAM

The code array divides into ninety-six one-kilobyte blocks, with the boot
cluster in blocks zero to three and the swap target at 02000H. The 8 KB of
volatile memory is what the larger images at this capacity are built around:
the flash library runs from RAM with room to spare, the self-RAM window is
reserved in the linker map, and in-field updates are the normal mode of
operation rather than an afterthought. A dump of such a board typically shows
both clusters populated, which means both generations of firmware are
recoverable and the boot flag state says which one is live.

Protection posture at this capacity

The option bytes, the two ten-byte identifiers and the shipped block
protections are family-standard, and at this size the boot-area reprogramming
protection matters more because the swap feature is in active use. The debug
gate in 000C3H with its erase-on-failure bit and the serial path through
TOOL0 complete the picture. On boards this size the identifiers are usually
both populated, and the work of getting a legitimate readout starts with
establishing which tool paths the production line actually used, because
those paths are the ones the identifiers were written for.

RAM as working evidence

Eight kilobytes is enough volatile memory that firmware keeps live state
across the control loop: setpoints, learned offsets, fault latches. On a
board that arrives dead, a capture of the RAM in its powered-down state,
taken before anything is rewritten, sometimes explains the fault that killed
the unit. The technique needs the supply held while the state is read out,
and it is part of the diagnostic side of the firmware extraction service workflow rather than
the plain imaging flow.

Bench notes

• Ninety-six blocks verify per kilobyte; a marginal pin shows up as a localised checksum failure, not a corrupt dump.
• The 8 KB data flash has its own block structure and protection flags; read it with the data-flash command set.
• The subsystem clock on X2 is standard here; boards without the crystal are usually running images ported from smaller members.

The 30-pin siblings are in R5F100AA flash data through R5F100AE firmware decryption, the 32-pin
equivalents begin at R5F100BA locked flash and reach 128 KB in R5F100BG flash data, and
the 96 KB die in a 40-pin package is R5F100EF flash memory. Older-architecture
comparisons for the same memory class, where the data flash did not exist as
a separate array at all, are in LPC2134FBD64 mcu flash memory. The chip reverse engineering service page covers the
examination flow when the board needs more than a readout.

Crossing into the 8 KB data class

At 96 KB the separate data store doubles to 8 KB, and this member is where
the 30-pin row makes that step. Ninety-six erase blocks carry the program,
the lowest four forming the boot region with its mirror behind it, and the
doubled array carries logs that a 4 KB part could not afford. Recovering
one of these boards without the data array leaves half the story untold:
the calibration revisions, fault counters and run-hour stamps that the
extra kilobytes exist to hold are exactly what a rebuilt controller needs
to behave like the unit it replaces.