M32C8A Datasheet, PDF (111/372 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M32C/80 Series

M32C/8A Group
10. Protection
10. Protection
The function protects important registers from being inadvertently overwritten in case of a program crash. Figure 10.1
shows the PRCR register.
The PRC2 bit in the PRCR register becomes 0 (write disable) by a write to the SFR area after the PRC2 bit is set to 1
(write enable). Set the PD9 or PS3 register immediately after the PRC2 bit is set to 1. Do not generate an interrupt or
a DMA or DMACII transfer between these two instructions. Bits PRC0, PRC1, and PRC3 do not become 0
automatically even after a write to the SFR area. Set bits PRC0, PRC1, and PRC3 to 0 by program.
Protect Register
b7 b6 b5 b4 b3 b2 b1 b0
Symbol
PRCR
Address
000Ah
After Reset
XXXX 0000b
Bit Symbol
Bit Name
Function
RW
PRC0
Protect bit 0⁽¹⁾
PRC1
Protect bit 1⁽¹⁾
PRC2
Protect bit 2⁽²⁾
Writing to registers CM0, CM1, CM2, MCD,
PLC0, and PLC1 is enabled
0: Write disable
RW
1: Write enable
Writing to registers PM0, PM1, PM2, INVC0,
and INVC1 is enabled
0: Write disable
RW
1: Write enable
Writing to registers PD9 and PS3 is enabled
0: Write disable
RW
1: Write enable
PRC3
Protect bit 3⁽¹⁾
Writing to registers VCR2 and D4INT is enabled
0: Write disable
RW
1: Write enable
−
(b7-b4)
Unimplemented.
Write 0. Read as undefined value.
−
NOTES:
1. Bits PRC0, PRC1, and PRC3 do not become 0 automatically even after a write to the SFR area. Set bits PRC0, PRC1, and
PRC3 to 0 by program.
2. The PRC2 bit becomes 0 by a write to the SFR area after the PRC2 bit is set to 1.
Figure 10.1 PRCR Register
Rev.1.00 Jul 15, 2007 Page 94 of 352
REJ09B0385-0100