HD64F3437TF16 Datasheet, PDF (568/752 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.

Writer Mode Transition Time: Commands cannot be accepted during the oscillation settling
period or the writer mode setup period. After the writer mode setup time, a transition is made to
memory read mode.
Table 21.21 Stipulated Transition Times to Command Wait State
Item
Symbol Min
Standby release (oscillation settling time) t_osc1
10
Writer mode setup time
t _bmv
10
V_CC hold time
t _dwn
0
Max
Unit Notes
ms
ms
ms
V_CC
RES
t_osc1
t_bmv
t_dwn
Memory
read mode
Command
wait state
Auto-program mode
Auto-erase mode
Command acceptance
Command
wait state
Normal/
abnormal
end
identification
Figure 21.23 Oscillation Settling Time, Boot Program Transfer Time,
and Power-Down Sequence
Cautions on Memory Programming
1. When programming addresses which have previously been programmed, carry out auto-
erasing before auto-programming.
2. When performing programming using writer mode on a chip that has been programmed/erased
in an on-board programming mode, auto-erasing is recommended before carrying out auto-
programming.
Notes: 1. The flash memory is initially in the erased state when the device is shipped by Hitachi.
For other chips for which the erasure history is unknown, it is recommended that auto-
erasing be executed to check and supplement the initialization (erase) level.
2. Auto-programming should be performed once only on the same address block.
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