M30280F6HP RENESAS [Renesas Technology Corp], M30280F6HP Datasheet - Page 86

• Manufacturer Part Number: M30280F6HP
• Description: 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/Tiny SERIES
• Manufacturer: RENESAS [Renesas Technology Corp]

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R
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8. Protection
e
E
1
. v
J
Figure 8.1 PRCR Register
6
In the event that a program runs out of control, this function protects the important registers so that they will
not be rewritten easily. Figure 8.1 shows the PRCR register. The following lists the registers protected by
the PRCR register.
The PRC2 bit is set to "0" (write enabled) if data is written to the SFR area after setting the PRC2 bit to "1"
(write enable). Set the PD9, PACR, S4C and NDDR 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 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 the SFR area. Set the PRC0, PRC1 and PRC3 bits to "0" by program.
0
C
2
9
0 .
2 /
B
• Registers protected by PRC0 bit: CM0, CM1, CM2, LPCC1, PLC0, ROCR and PCLKR registers
• Registers protected by PRC1 bit: PM0, PM1, PM2, TB2SC, INVC0 and INVC1 registers
• Registers protected by PRC2 bit: PD9 , PACR, S4C and NDDR registers
• Registers protected by PRC3 bit: VCR2 and D4INT registers
0
0
8
0
4
G
Protect Register
J
7
b7
a
NOTE:
o r
0 -
. n
u
b6
1. The PRC2 bit is set to "0" if data is written to the SFR area after the PRC2 bit is set to "1". The
2
3
p
0
, 1
PRC0, PRC1 and PRC3 bits are not automatically set to "0". Set them to "0" by program.
0
b5
0
(
M
2
b4
0
0
1
0
6
7
b3
C
2 /
b2
, 8
page 66
b1
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1
b0
6
C
Bit Symbol
f o
2 /
(b5-b4)
(b7-b6)
PRC0
PRC1
PRC3
PRC2
8
Symbol
PRCR
3
) B
8
5
Nothing is assigned. When write, set to "0". When read, its
content is indeterminate.
Protect Bit 0
Protect Bit 1
Protect Bit 2
Protect Bit 3
Reserved Bit
Bit Name
Address
000A
16
After Reset
XX000000
Enable write to CM0, CM1, CM2,
LPCC1, ROCR, PLC0 and PCLKR
registers
Enable write to PM0, PM1, PM2,
TB2SC, INVC0 and INVC1
registers
Enable write to PD9, PACR
and S4C registers
Enable write to VCR2 and D4INT
registers
0 : Write protected
1 : Write enabled
0 : Write protected
1 : Write enabled
0 : Write protected
1 : Write enabled
0 : Write protected
1 : Write enabled
Set to "0"
2
Function
(1)
RW
RW
RW
RW
RW
RW
8. Protection