HD64F3437TF16 Datasheet, PDF (470/752 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.

20.2 Flash Memory Register Descriptions
20.2.1 Flash Memory Control Register (FLMCR)
FLMCR is an 8-bit register that controls the flash memory operating modes. Transitions to
program mode, erase mode, program-verify mode, and erase-verify mode are made by setting bits
in this register. FLMCR is initialized to H'00 by a reset, in the standby modes, and when 12 V is
not applied to FV_PP. When 12 V is applied to the FV_PP pin, a reset or entry to a standby mode
initializes FLMCR to H'80.
Bit
7
6
5
4
3
2
1
0
V_PP
—
—
—
EV
PV
E
P
Initial value*
0
0
0
0
0
0
0
0
Read/Write
R
—
—
—
R/W* R/W* R/W* R/W*
Note: * The initial value is H'00 in modes 2 and 3 (on-chip flash memory enabled). In mode 1 (on-
chip flash memory disabled), this register cannot be modified and always reads H'FF. For
information on accessing this register, refer to in section 20.7, Flash Memory Programming
and Erasing Precautions (11).
Bit 7—Programming Power (V_PP): This status flag indicates that 12 V is applied to the FV_PP pin.
Refer to section 20.7, Flash Memory Programming and Erasing Precautions (5), for details on use.
Bit 7: V_PP
0
1
Description
Cleared when 12 V is not applied to FV_PP
Set when 12 V is applied to FV_PP
(Initial value)
Bits 6 to 4—Reserved: Read-only bits, always read as 0.
Bit 3—Erase-Verify Mode (EV):^*1 Selects transition to or exit from erase-verify mode.
Bit 3: EV
0
1
Description
Exit from erase-verify mode
Transition to erase-verify mode
(Initial value)
Bit 2—Program-Verify Mode (PV):^*1 Selects transition to or exit from program-verify mode.
Bit 2: PV
0
1
Description
Exit from program-verify mode
Transition to program-verify mode
(Initial value)
441