HD64F2638F20J Datasheet, PDF (931/1512 Pages) Renesas Technology Corp – Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2600 Series

H8S/2639, H8S/2638, H8S/2636,
H8S/2630, H8S/2635 Group
Section 21C ROM
(H8S/2635 Group)
21C.9.2 Program-Verify Mode
In program-verify mode, the data written in program mode is read to check whether it has been
correctly written in the flash memory.
After the elapse of the given programming time, clear the P bit in FLMCR1, then wait for at least
(t_cp) µs before clearing the PSU bit to exit program mode. After exiting program mode, the
watchdog timer setting is also cleared. The operating mode is then switched to program-verify
mode by setting the PV bit in FLMCR1. Before reading in program-verify mode, a dummy write
of H'FF data should be made to the addresses to be read. The dummy write should be executed
after the elapse of (t_spv) µs or more. When the flash memory is read in this state (verify data is read
in 16-bit units), the data at the latched address is read. Wait at least (t_spvr) µs after the dummy write
before performing this read operation. Next, the originally written data is compared with the verify
data, and reprogram data is computed (see figure 21C-12) and transferred to RAM. After
verification of 128 bytes of data has been completed, exit program-verify mode, wait for at least
(t_cpv) µs, then clear the SWE bit in FLMCR1. If reprogramming is necessary, set program mode
again, and repeat the program/program-verify sequence as before. The maximum number of
repetitions of the program/program-verify sequence is indicated by the maximum programming
count (N). Leave a wait time of at least (t_cswe) µs after clearing SWE.
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 P bit in FLMCR1 is
set. In the chip, 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 chip, the number of loops in
reprogramming processing is guaranteed not to exceed the maximum value of the
maximum programming count (N).
REJ09B0103-0800 Rev. 8.00
May 28, 2010
Page 881 of 1458