438
Bit 1—Erase Mode (E):
*1, *2
Selects transition to or exit from erase mode.
Bit 1: E
Description
0
Exit from erase mode
(Initial value)
1
Transition to erase mode
Bit 0—Program Mode (P):
*1, *2
Selects transition to or exit from program mode.
Bit 0: P
Description
0
Exit from program mode
(Initial value)
1
Transition to program mode
Notes: *1 Do not set two or more of these bits simultaneously. Do not release or shut off the V
CC
or V
PP
power supply when these bits are set.
*2 Set the P or E bit according to the instructions given in section 20.4, Programming and
Erasing Flash Memory.
Set the watchdog timer beforehand to make sure that these bits do not remain set for
longer than the specified times.
For notes on use, see section 20.7, Flash Memory Programming and Erasing
Precautions.
20.2.2
Erase Block Register 1 (EBR1)
EBR1 is an 8-bit register that designates large flash-memory blocks for programming and erasure.
EBR1 is initialized to H'00 by a reset, in the standby modes, and when 12 V is not applied to the
FV
PP
pin. When a bit in EBR1 is set to 1, the corresponding block is selected and can be
programmed and erased. Figure 20.2 and table 20.6 show details of a block map.
Bit
7
6
5
4
3
2
1
0
LB7
LB6
LB5
LB4
LB3
LB2
LB1
LB0
Initial value
*
1
Read/Write
0
0
0
0
0
0
0
0
R/W
*
1,
*
2
R/W
*
1
R/W
*
1
R/W
*
1
R/W
*
1
R/W
*
1
R/W
*
1
R/W
*
1
Notes:
*
1 The initial value is H'00 in modes 2 and 3 (on-chip ROM enabled). In mode 1 (on-chip
ROM disabled), this register cannot be modified and always reads H'FF.
*
2 This bit cannot be modified mode 2.
For information on accessing this register, refer to in section 20.7, Flash Memory
Programming and Erasing Precautions (11).