R01UH0823EJ0100 Rev.1.00
Page 257 of 1823
Jul 31, 2019
RX23W Group
13. Register Write Protection Function
13.1
Register Descriptions
13.1.1
Protect Register (PRCR)
Note 1. Write data is not retained.
PRCi Bits (Protect Bit i) (i = 0 to 3)
These bits enable or disable writing to the corresponding registers to be protected.
Setting the PRCi bits to 1 and 0 enable and disable writing to the corresponding registers to be protected, respectively.
Address(es): 0008 03FEh
b15
b14
b13
b12
b11
b10
b9
b8
b7
b6
b5
b4
b3
b2
b1
b0
PRKEY[7:0]
—
—
—
—
PRC3
PRC2
PRC1
PRC0
Value after reset:
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bit
Symbol
Bit Name
Function
R/W
b0
Protect Bit 0
Enables writing to the registers related to the clock generation circuit.
0: Write disabled
1: Write enabled
R/W
b1
Protect Bit 1
Enables writing to the registers related to operating modes, low power
consumption functions, the clock generation circuit, and software reset.
0: Write disabled
1: Write enabled
R/W
b2
PRC2
Protect Bit 2
Enables writing to the registers related to the low power timer.
0: Write disabled
1: Write enabled
R/W
b3
Protect Bit 3
Enables writing to the registers related to the LVD.
0: Write disabled
1: Write enabled
R/W
b7 to b4
—
Reserved
These bits are read as 0. The write value should be 0.
R/W
b15 to b8
PRKEY[7:0] PRC Key Code
These bits control permission and prohibition of writing to the PRCR
register.
To modify the PRCR register, write A5h to the 8 higher-order bits and the
desired value to the 8 lower-order bits as a 16-bit unit.