HD6432621 Hitachi, HD6432621 Datasheet - Page 682

• Manufacturer Part Number: HD6432621
• Description: (HD64F262x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

19.7
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 for addresses
H'000000 to H'03FFFF are made by setting the PSU1, ESU1, P1, E1, PV1, and EV1 bits in
FLMCR1.
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 22.6, Flash Memory
Characteristics.
Notes: 1. Operation is not guaranteed if setting/resetting of the SWE1, ESU1, PSU1, EV1, PV1,
638
2. When programming or erasing, set FWE to 1 (programming/erasing will not be
3. Programming must be executed in the erased state. Do not perform additional
Flash Memory Programming/Erasing
E1, and P1 bits in FLMCR1 is executed by a program in flash memory.
executed if FWE = 0).
programming on addresses that have already been programmed.