HD64F3437TF16 Datasheet, PDF (430/752 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.

Sample Block-Erase Program: This program uses the following registers.
R0: Specifies block to be erased, and also stores address used in prewrite and erase-verify.
R1H: Stores data to be read, and also used for dummy write.
R2: Stores last address of block to be erased.
R3: Stores address used in prewrite and erase-verify.
R4: Sets timing loop counters for prewrite, prewrite-verify, erase, and erase-verify, and also
stores register setting value.
R5: Sets prewrite and erase timing loop counters.
R6L: Used for prewrite-verify and erase-verify fail count.
The setting of #a, #b, #c, #d, and #e values in the program depends on the clock frequency. Set #a,
#b, #c, #d, and #e values according tables 19.9 (1) and (2), and 19.10. Erase block registers (EBR1
and EBR2) should be set according to sections 19.2.2 and 19.2.3. #BLKSTR and #BLKEND are
the top and last addresses of the block to be erased. Set #BLKSTR and #BLKEND according to
figure 19.2.
401