HD64F2638F20J Datasheet, PDF (928/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

Section 21C ROM
(H8S/2635 Group)
H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
21C.9 Programming/Erasing Flash Memory
A software method, using the CPU, is employed to program and erase flash memory in the on-
board programming modes. There are four flash memory operating modes: program mode, erase
mode, program-verify mode, and erase-verify mode. Transitions to these modes are made by
setting the PSU, ESU, P, E, PV, and EV bits in FLMCR1 for on-chip flash memory.
The flash memory cannot be read while it is being written or erased. The flash memory cannot be
read while being programmed or erased. Therefore, the program (user program) that controls flash
memory programming/erasing should be located and executed in on-chip RAM or external
memory. If the program is to be located in external memory, the instruction for writing to flash
memory, and the following instruction, should be placed in on-chip RAM. Also ensure that the
DTC is not activated before or after execution of the flash memory write instruction.
In the following operation descriptions, wait times after setting or clearing individual bits in
FLMCR1 are given as parameters; for details of the wait times, see section 24.2.7 and 24.3.7,
Flash Memory Characteristics.
Notes: 1. Operation is not guaranteed if bits SWE, ESU, PSU, EV, PV, E, and P of FLMCR1 are
set/reset by a program in flash memory in the corresponding address areas.
2. When programming or erasing, set FWE to 1 (programming/erasing will not be
executed if FWE = 0).
3. Programming should be performed in the erased state. Do not perform additional
programming on previously programmed addresses.
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REJ09B0103-0800 Rev. 8.00
May 28, 2010