HD6432633 Datasheet, PDF (980/1453 Pages) Renesas Technology Corp – Series of Microcomputers (MCUs: microcomputer units)

Notes on Program/Program-Verify Procedure
1. In order to perform 128-byte-unit programming, the lower 8 bits of the write start address must
be H'00 or H'80.
2. When performing continuous writing of 128-byte data to flash memory, byte-unit transfer
should be used.
128-byte data transfer is necessary even when writing fewer than 128 bytes of data. Write H'FF
data to the extra addresses.
3. Verify data is read in word units.
4. The write pulse is applied and a flash memory write executed while the P1 bit in FLMCR1 is
set. In the H8S/2633, write pulses should be applied as follows in the program/program-verify
procedure to prevent voltage stress on the device and loss of write data reliability.
a. After write pulse application, perform a verify-read in program-verify mode and apply a
write pulse again for any bits read as 1 (reprogramming processing). When all the 0-write
bits in the 128-byte write data are read as 0 in the verify-read operation, the
program/program-verify procedure is completed. In the H8S/2633, the number of loops in
reprogramming processing is guaranteed not to exceed the maximum value of the
maximum programming count (N).
b. After write pulse application, a verify-read is performed in program-verify mode, and
programming is judged to have been completed for bits read as 0.
c. If programming of other bits is incomplete in the 128 bytes, reprogramming processing
should be executed. If a bit for which programming has been judged to be completed is
read as 1 in a subsequent verify-read, a write pulse should again be applied to that bit.
5. The period for which the P1 bit in FLMCR1 is set (the write pulse width) should be changed
according to the degree of progress through the program/program-verify procedure. For
detailed wait time specifications, see section 25.6 and 26.6, Flash Memory Characteristics.
6. The program/program-verify flowchart for the H8S/2633 is shown in figure 22-12.
To cover the points noted above, bits on which reprogramming processing is to be executed,
and bits on which additional programming is to be executed, must be determined as shown
below.
Since reprogram data and additional-programming data vary according to the progress of the
programming procedure, it is recommended that the following data storage areas (128 bytes
each) be provided in RAM.
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