HD64F3028F25 Datasheet, PDF (650/925 Pages) Renesas Technology Corp – Hardware Manual Renesas 16-Bit Single-Chip Microcomputer H8 Family/H8/300H Series

Also note that access to the flash memory space by means of a MOV instruction, etc., is not
permitted while the P bit or E bit is set.
6. Do not set or clear the SWE bit during execution of a program in flash memory.
Clear the SWE bit before executing a program or reading data in flash memory. When the
SWE bit is set, data in flash memory can be rewritten, but flash memory should only be
accessed for verify operations (verification during programming/erasing).
Similarly, when using the RAM emulation function while a high level is being input to the
FWE pin, the SWE bit must be cleared before executing a program or reading data in flash
memory. However, the RAM area overlapping flash memory space can be read and written to
regardless of whether the SWE bit is set or cleared.
A wait time is necessary after the SWE bit is cleared. For details see table 21.19 in section
21.2.6, Flash Memory Characteristics.
7. Do not use interrupts while flash memory is being programmed or erased.
All interrupt requests, including NMI, should be disabled during FWE application to give
priority to program/erase operations (including emulation in RAM).
Bus release must also be disabled.
8. Do not perform additional programming. Erase the memory before reprogramming.
In on-board programming, perform only one programming operation on a 128-byte
programming unit block. Programming should be carried out with the entire programming unit
block erased.
9. Before programming, check that the chip is correctly mounted in the PROM writer.
Overcurrent damage to the device can result if the index marks on the PROM writer socket,
socket adapter, and chip are not correctly aligned.
10. Do not touch the socket adapter or chip during programming.
Touching either of these can cause contact faults and write errors.
11. A wait time of 100 µs or more is necessary when performing a read after a transition to
normal mode from program, erase, or verify mode.
12. Use byte access on the registers that control the flash memory (FLMCR1, FLMCR2,
EBR1, EBR2, and RAMCR).
Rev. 2.00, 09/03, page 618 of 890