H8S2472 Datasheet, PDF (1063/1250 Pages) Renesas Technology Corp – 16-Bit Single-Chip Microcomputer H8S Family / H8S/2400 Series

Section 25 Flash Memory
11. If data other than H'FFFFFFFF is written to the key code area (H'00003C to H'00003F) of
flash memory, only H'00 can be read in programmer mode. (In this case, data is read as H'00.
Rewrite is possible after erasing the data.) For reading in programmer mode, make sure to
write H'FFFFFFFF to the entire key code area. If data other than H'FF is to be written to the
key code area in programmer mode, a verification error will occur unless a software
countermeasure is taken for the PROM programmer and the version of its program.
12. The programming program that includes the initialization routine and the erasing program that
includes the initialization routine are each 3 Kbytes or less. Accordingly, when the CPU clock
frequency is 34 MHz, the download for each program takes approximately 180 µs at the
maximum.
13. While an instruction in on-chip RAM is being executed, the DTC can write to the SCO bit in
FCCS that is used for a download request or FMATS that is used for MAT switching. Make
sure that these registers are not accidentally written to, otherwise an on-chip program may be
downloaded and damage RAM or a MAT switchover may occur and the CPU get out of
control. Do not use DTC to program flash related registers.
14. A programming/erasing program for flash memory used in the conventional H8S F-ZTAT
microcomputer which does not support download of the on-chip program by a SCO transfer
request cannot run in this LSI. Be sure to download the on-chip program to execute
programming/erasing of flash memory in this LSI.
15. Unlike the conventional H8S F-ZTAT microcomputer, no countermeasures are available for a
runaway by WDT during programming/erasing. Prepare countermeasures (e.g. use of the
periodic timer interrupts) for WDT with taking the programming/erasing time into
consideration as required.
Rev. 2.00 Aug. 20, 2008 Page 1015 of 1198
REJ09B0403-0200