Half-millimetre pitch, eighty pins, 256 KB of flash: R5F524TAADFN is the compact version of the RX24T motor controller, and it is the variant most often found on boards that were cost-reduced after the first prototype. The die is identical to the 0.65 mm package part. What differs is how much room there is to reach it.
Access Before Anything Else
On a 0.50 mm LFQFP, the gap between leads is small enough that a hand probe is a bad idea. Three routes exist, and the choice is made from a photograph of the board rather than from the part number:
– Programming pads left open on the PCB – the fastest route, and common on boards that were programmed after assembly. – Pads under conformal coating – the coating is removed locally, the pads are used, and the area is re-coated on return. – No accessible pads – a pogo fixture built for the package, or removal with a hot-air station and a replacement footprint.
Each route ends at the same place: the array is read, not modified.
The Memory Picture
Code is at FFFC0000h to FFFFFFFFh in 2 KB blocks. The E2 data flash is a separate eight kilobytes with its own erase granularity and a one-million-cycle rating. Sixteen kilobytes of RAM sits inside the die, and on this class of product it is almost always fully committed: one control loop, one communication path, one diagnostic buffer.
Protection In Plain Terms
The RX24T has four protection features that customers tend to lump together as “the chip is locked”. ID code protection gates boot-mode SCI and the on-chip debugging emulator. ROM code protection is a value in block 0 that disables reading and rewriting through a parallel programmer. Start-up program protection pairs blocks 0 to 7 with 8 to 15 so a bootloader can update without erasing itself. Area protection limits self-programming to chosen blocks.
Only a block erase destroys data. None of the four performs one. That is the whole basis on which a locked part can still be recovered.
What Comes Back
An Intel HEX over the ROM window, a separate binary for the E2 area, the option bytes, a block map showing which 2 KB blocks carried data, and a page with the ID code, the control code byte, and the silicon revision. If the board was alive at intake, the page also carries the clock tree and PWM configuration.
Judging The Dump
A production image fills blocks in order and leaves little blank space at the bottom of the array. A development image leaves gaps and often has an unerased region near the start of the block map. Reading that pattern tells a rebuild team whether they are looking at the shipped firmware or at a bench build, which matters when two units from the same product disagree.
Fixture Or Removal
A pogo fixture is worth building when several units of the same board are expected. For a single unit, removal and reballing is usually faster and always cheaper. The decision is made from the quantity, not from the difficulty of the package.
Either way the array is read without an erase, and the board is returned in the state it can be returned in. Customers should know in advance that a removed package is not reflowed back on unless that is ordered separately.
Getting A Quote
Send the board, the rail voltage, and a note on whether the design drives one motor or two. Pack against foam; do not attempt to remove coating yourself, since the wrong solvent takes the silkscreen with it.
Start at the services desk or ask through the contact form. The 0.65 mm package twin is R5F524TAADFF, and the 64-pin device is R5F524TAADFM.