M32CSLASH8A datasheet(111/372 Pages) RENESAS

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M32C/8A Group

10. Protection

Rev.1.00

Jul 15, 2007

Page 94 of 352

REJ09B0385-0100

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.

Figure 10.1

PRCR Register

b7 b6 b5 b4

Protect Register

Symbol

PRCR

Address

000Ah

Bit Symbol

Bit Name

After Reset

XXXX 0000b

Function

PRC0

PRC1

PRC2

PRC3

Writing to registers CM0, CM1, CM2, MCD,

PLC0, and PLC1 is enabled

0: Write disable

1: Write enable

Protect bit 0(1)

Protect bit 1(1)

Writing to registers PM0, PM1, PM2, INVC0,

and INVC1 is enabled

0: Write disable

1: Write enable

Protect bit 2(2)

Writing to registers PD9 and PS3 is enabled

0: Write disable

1: Write enable

Protect bit 3(1)

Writing to registers VCR2 and D4INT is enabled

0: Write disable

1: Write enable

Unimplemented.

Write 0. Read as undefined value.

−

(b7-b4)

−

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.

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