HD64F3437TF16 Datasheet, PDF (429/752 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.

Prewrite Flowchart
Start
Set erase block register
(set bit of block to be programmed to 1)
Set start address^*5
n=1
Write H'00 to flash memory
(Flash memory latches
write address and write data)^*1
Address + 1 → address
Enable watchdog timer^*2
Select program mode
( P bit = 1 in FLMCR)
Wait (x) µs^*4
Clear P bit
Disable watchdog timer
Wait (t_VS1) µs^*4
Prewrite verify^*3
(read data = H'00?)
Notes: *1 Use a byte transfer instruction.
*2 Set the timer overflow interval to the
shortest value (CKS2, CKS1, CKS0
all cleared to 0).
*3 In prewrite-verify mode P, E, PV,
and EV are all cleared to 0 and 12 V
is applied to FV_PP. Read the data
with a byte transfer instruction.
End of programming
*4 x: 10 to 20 µs
t_VS1: 4 µs or more
N: 50 (set N so that total
programming time does not
exceed 1 ms)
*5 Start and last addresses shall be top
and last addresses of the block to be
erased.
No go
OK
Last address?^*5
No
Yes
Clear erase block register
(clear bit of programmed block to 0)
n ≥ N?^*4
Yes
Programming error
No
n + 1→ n
End of prewrite
Figure 19.10 Prewrite Flowchart
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