HD64F3437TF16 Datasheet, PDF (487/752 Pages) Hitachi Semiconductor – 12 V must not be applied to the S-mask model (single-power-supply specification), as this may permanently damage the device.

20.4.3 Programming Flowchart and Sample Program
Flowchart for Programming One Byte
Start
Set erase block register
(set bit of block to be programmed to 1)
Write data to flash memory (flash
memory latches write
address and data)^*1
n=1
Enable watchdog timer^*2
Select program mode
(P bit = 1 in FLMCR)
Wait (x) µs^*4
Clear P bit
Disable watchdog timer
Select program-verify mode
(PV bit = 1 in FLMCR)
Wait (t_vs1) µs^*5
Verify^*3 (read memory)
OK
Clear PV bit
End of programming
No go
Notes: *1 Write the data to be programmed
with a byte transfer instruction.
*2 Set the timer overflow interval as
follows.
CKS2 = 0, CKS1 = 0, CKS0 = 1
*3 Read the memory data to be
verified with a byte transfer
instruction.
*4 Programming time x, which is
determined by the initial time × 2^n–1
(n = 1, 2, 3, 4, 5, 6), increases in
proportion to n. Thus, set the initial
time to 15.8 µs or less to make total
programming time 1 ms or less.
*5 t_VS1: 4 µs or more
N: 6 (set N so that total
programming time does not
exceed 1 ms)
Clear PV bit
End of verification
Clear erase block register
(clear bit of programmed block to 0)
End (1-byte data programmed)
n ≥ N?^*5
Yes
Programming error
No
n+1→n
Double programming time
(x × 2→x)
Figure 20.8 Programming Flowchart
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