Hitachi H8/3022 Hardware Manual page 472

H8/3022 series hitachi single-chip microcomputer
Table of Contents

Advertisement

128-byte data transfer is necessary even when writing fewer than 128 bytes of data. H'FF data
must be written 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 P bit in FLMCR1 is
set. In the H8/3022F, 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 H8/3022F, the number of loops in
reprogramming processing is guaranteed not to exceed 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. The following processing
is necessary for programmed bits.
When programming is completed at an early stage in the program/program-verify
procedure:
If programming is completed in the 1st to 6th reprogramming processing loop, additional
programming should be performed on the relevant bits. Additional programming should
only be performed on bits which first return 0 in a verify-read in certain reprogramming
processing.
When programming is completed at a late stage in the program/program-verify procedure:
If programming is completed in the 7th or later reprogramming processing loop, additional
programming is not necessary for the relevant bits.
c. If programming of other bits is incomplete in the 128 bytes, reprogramming process 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 P 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 18.2.5, Flash Memory Characteristics.
461

Advertisement

Table of Contents
loading

This manual is also suitable for:

H8/3021H8/3020H8/3022 f-ztat

Table of Contents