H8S2114R Datasheet, PDF (873/1038 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2100 Series

Section 21 Flash Memory (0.18-µm F-ZTAT Version)
11. If data other than H'FF (4 bytes) is written to the key code area (in normal mode: H'001E to
H'001F, in advance mode: H'00003C to H'00003F) of flash memory, reading cannot be
performed 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'FF 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
version of program.
12. The code size of the programming program that includes the initialization routine or the
erasing program that includes the initialization routine is 2 kbytes or less. Accordingly, when
the CPU clock frequency is 20 MHz, the download for each program takes approximately 200
µs at the maximum.
13. While an instruction in the 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 the on-chip RAM or a MAT switchover may occur and the CPU get
out of control. Do not use the DTC to write to flash memory 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 H8S F-ZTAT microcomputer.
15. Unlike the conventional H8S F-ZTAT microcomputer, no countermeasures are available for a
runaway by the WDT during programming/erasing. Prepare countermeasures (e.g. use of
periodic timer interrupts) for the WDT with taking the programming/erasing time into
consideration as required.
Rev. 3.00 Jul. 14, 2005 Page 825 of 986
REJ09B0098-0300