m30833fjgp Renesas Electronics Corporation., m30833fjgp Datasheet - Page 111

• Manufacturer Part Number: m30833fjgp
• Description: Renesas 16/32-bit Single-chip Microcomputer M16c Family / M32c/80 Series
• Manufacturer: Renesas Electronics Corporation.

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9. Protection
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Figure 9.1 PRCR Register
2
0
The protection function protects important registers from being easily overwritten when a program runs out of
control.
Figure 9.1 shows the PRCR register. Each bit in the PRCR register protects the following registers:
The PRC2 bit is set to "0" (write disable) when data is written to a desired address after setting the PRC2 bit
to "1" (write enable). Set the PD9 and PS3 registers immediately after setting the PRC2 bit in the PRCR
register to "1" (write enable). Do not generate an interrupt or a DMA transfer between the instruction to set
to the PRC2 bit to "1" and the following instruction. The PRC0, PRC1 and PRC3 bits are not set to "0" even
if data is written to desired addresses. Set the PRC0, PRC1 and PRC3 bits to "0" by program.
1
C
9
3 .
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• The PRC0 bit protects the CM0, CM1, CM2, MCD, PLC0 and PLC1 registers;
• The PRC1 bit protects the PM0, PM1, PM2, INVC0 and INVC1 registers;
• The PRC2 bit protects the PD9 and PS3 registers;
• The PRC3 bit protects the PLV and VDC0 registers.
0
1
3
0
3
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4
a
0 -
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Protect Register
NOTES:
b7
3 .
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1. The PRC2 bit can be set to "0" by writing to a desired address after the PRC2 bit is set to "1".
, 1
3
p
b6
1
The PRC0, PRC1 and PRC3 bits are not automatically set to "0". Set to"0" by program.
2
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0
b5
0
3
6
2
b4
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b3
Page 88
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b1
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b0
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4
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(b7 - b4)
Symbol
8
PRC0
PRC1
PRC2
PRC3
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8
Bit
Symbol
PRCR
Protect Bit 0
Protect Bit 1
Protect Bit 2
Protect Bit 3
Nothing is assigned. When write, set to "0".
When read, its content is indeterminate.
Bit Name
Address
000A
(1)
16
Enables writing to PLV, VDC0 and
VDC1 registers
0 : Write disable
1 : Write enable
Enables writing to CM0, CM1, CM2,
MCD, PLC0, PLC1 registers
0 : Write disable
1 : Write enable
Enables writing to PM0, PM1, INVC0,
INVC1 registers
0 : Write disable
1 : Write enable
Enables writing to PD9, PS3 registers
0 : Write disable
1 : Write enable
After Reset
XXXX 0000
Function
2
RW
RW
RW
RW
RW
9. Protection