SH7280 Datasheet, PDF (1464/1726 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine family

Section 26 Flash Memory
(3.3) Erasure
Similar to as in programming, there is an entry point of the erasing program in the area from
(download start address set by FTDAR) + 16 bytes of on-chip RAM. The subroutine is called
and erasing is executed by using the following steps.
MOV.L #DLTOP+16,R1
JSR @R1
NOP
; Set entry address to R1
; Call erasing routine
1. The general registers other than R0 are saved in the erasing program.
2. R0 is a return value of the FPFR parameter.
3. Since the stack area is used in the erasing program, a stack area of maximum 128 bytes
must be reserved in RAM.
(3.4) The return value in the erasing program, FPFR (general register R0) is checked.
(3.5) Determine whether erasure of the necessary blocks has finished.
If more than one block is to be erased, update the FEBS parameter and repeat steps (3.2) to
(3.5). Blocks that have already been erased can be erased again.
(3.6) After erasure finishes, clear FKEY and specify software protection.
If this LSI is restarted by a power-on reset immediately after user MAT erasing has finished,
secure a reset period (period of RES = 0) that is at least as long as the normal 100 µs.
Rev. 1.00 Jun. 26, 2008 Page 1434 of 1692
REJ09B0393-0100