HD64F38024HV Datasheet, PDF (192/684 Pages) Renesas Technology Corp – Hardware Manual Renesas 8-Bit Single-Chip Microcomputer H8 Family/H8/300L Super Low Power Series

Section 6 ROM
6.7.3 Notes on On-Board Programming
1. You must use the system clock oscillator when programming or erasing flash memory on the
H8/38124 Group. The on-chip oscillator should not be used for programming or erasing flash
memory. See section 4.2, On-Chip Oscillator Selection Method, for information on switching
between the system clock oscillator and the on-chip oscillator.
2. On the H8/38124 Group the watchdog timer operates after a reset is canceled. When executing
a program prepared by the user that performs programming and erasing in the user mode, the
watchdog timer’s overflow cycle should be set to an appropriate value. Refer to section 6.8.1,
Program/Program-Verify, for information on the appropriate watchdog timer overflow cycle
for programming, and refer to section 6.8.2, Erase/Erase-Verify, for information on the
appropriate watchdog timer overflow cycle for erasing.
6.8 Flash Memory Programming/Erasing
A software method using the CPU is employed to program and erase flash memory in the on-
board programming modes. Depending on the FLMCR1 setting, the flash memory operates in one
of the following four modes: Program mode, program-verify mode, erase mode, and erase-verify
mode. The programming control program in boot mode and the user program/erase control
program in user program mode use these operating modes in combination to perform
programming/erasing. Flash memory programming and erasing should be performed in
accordance with the descriptions in section 6.8.1, Program/Program-Verify and section 6.8.2,
Erase/Erase-Verify, respectively.
6.8.1 Program/Program-Verify
When writing data or programs to the flash memory, the program/program-verify flowchart shown
in figure 6.10 should be followed. Performing programming operations according to this
flowchart will enable data or programs to be written to the flash memory without subjecting the
chip to voltage stress or sacrificing program data reliability.
1. Programming must be done to an empty address. Do not reprogram an address to which
programming has already been performed.
2. Programming should be carried out 128 bytes at a time. A 128-byte data transfer must be
performed even if writing fewer than 128 bytes. In this case, H'FF data must be written to the
extra addresses.
3. Prepare the following data storage areas in RAM: A 128-byte programming data area, a 128-
byte reprogramming data area, and a 128-byte additional-programming data area. Perform
Rev. 8.00 Mar. 09, 2010 Page 170 of 658
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