Hitachi H8/3048 Hardware Manual page 584

Bit 7—Programming Power (V
displayed as "1" or "0." The permissible output currents for impressed high voltage VH are given
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in 21.3.1, "DC Characteristics." The value of VH ranges from V
excess of VH is applied, "1" is displayed; otherwise "0" is displayed.
This bit restricts the hardware protect functions during write and erase operations for the flash
memory. For details on hardware protect, see 18.7.8, "Protect Modes." For notes on VPP usage,
see 10.10, "Flash Memory Programming and Erasing Precautions."
Bit 7
V Description
PP
0 [Clear conditions]
This is the regular operational mode when a voltage exceeding
VH is not applied to the V
written or erased. "Hardware Protect" is displayed.
1 [Set conditions]
This is the operational mode when a voltage exceeding VH is
applied to the V
erased. "Hardware Protect Disabled" is displayed*.
Note: For correct write and erase functions, the setting should be V
12.6 V).
Bit 6—V Enable (V
PP
set, it is necessary to wait for at least 5 µs for the internal power supply to stabilize; programming
and erasing cannot be performed until stabilization is complete. After this bit is cleared, it is
necessary to wait for the flash memory read setup time (t
Bit 6
V E Description
PP
0 V
PP
1 V
PP
Note: The power supply system used for the flash memory is switched by means of the VppE bit.
After switching, operation is not guaranteed during the period before the power supply
system stabilizes. It is therefore prohibited to fetch from flash memory and execute an
instruction that sets or resets the VppE bit.
): Programming power bit (V
PP
pin. The flash memory cannot be
PP
pin. The flash memory can be written and
PP
E): Disables or enables 12-V application to the V
PP
pin 12-V power supply is disabled
pin 12-V supply is enabled
) detects V
PP
+ 2 V to 11.4 V. If a voltage in
CC
= 12.0 V to 0.6 V (11.4 V to
PP
) in order to read flash memory.
FRS
575
, and level is
PP
(Initial value)
pin. After this bit is
PP
(Initial value)