M16C30P_07 Datasheet, PDF (245/317 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/30 SERIES

M16C/30P Group
20. One Time Flash Version
20.1 Low Consumption Mode
The one time flash memory version enters the low power consumption mode to reduce the power consumption by
stopping the one time flash memory. Figure 20.1 shows the FMR0 Register in One Time Flash Memory and Figure
20.2 shows the processing before and after low power consumption mode.
To enter stop mode or wait mode, set the FMR01 bit in the FMR0 register to 0 (FMSTP bit disabled).
For models including the PM13 bit, when the FMR01 bit in the FMR0 register is 1 (FMSTP bit enabled), the PM13
bit in the PM1 register automatically becomes 1. Store the program to change the FMSTP bit either in external area
that is usable when the PM13 bit is set to 1. When the FMR01 bit is changed to 0 (FMSTP bit disabled), the PM13
bit is set back to the value before the change. However, when the PM13 bit value is changed while the FMR01 bit
is 1, the changed value is reflected after the FMR01 bit is set to 0. External area does not change depending on
FMR01 bit status for models without the PM13 bit. Refer to Figure 6.2 PM1 Register (1) and Figure 6.3 PM1
Register (2) for availability of the PM13 bit in the PM1 Register.
Flash Memory Control Register 0
b7 b6 b5 b4 b3 b2 b1 b0
0000 0
Symbol
FMR0
Address
01B7h
After Reset
00000001b
Bit Symbol
Bit Name
Function
RW
—
Reserved Bit
(b1)
The value in this bit w hen read is indeterminate
RO
FMSTP Enable Bit ⁽¹⁾
0 : FMSTP bit disabled
FMR01
1 : FMSTP bit enabled
RW
—
Reserved Bit
Set to “0”
(b2)
RW
One time Flash Memory Stop 0 : Enables one time flash memory operation
Bit ^{(2, 3)}
FMSTP
1 : Stops one time flash memory operation
(placed in low pow er mode, flash memory
RW
initialized)
—
Reserved Bit
Set to “0”
(b5-b4)
RW
—
Reserved Bit
Set to “0”
(b7-b6)
RO
NOTES :
1. To set this bit to “1,” w rite “0” and then “1” in succession. Make sure no interrupts or DMA transfers w ill occur
before w riting “1” after w riting “0”.
____
Write to this bit w hen the NMI pin is in the high state.
2. Set this bit in a program area other than the one time flash memory area.
3. Effective w hen the FMR01 bit = 1 (FMSTP bit enabled). If the FMR01 bit = 0, although the FMSTP bit can be set to “1”
by w riting “1” by program, the one time flash memory is neither placed in low pow er mode nor initialized.
Figure 20.1 FMR0 Register in One Time Flash Version
Rev.1.22 Mar 29, 2007 Page 229 of 291
REJ09B0179-0122