231
3. Register configuration
Table 9.17 shows the register configuration of the watchdog timer.
Table 9.17
Watchdog Timer Registers
Name
Abbrev.
R/W
Initial Value
Address
Timer control/status register W
TCSRW
R/W
H'AA
H'FFB2
Timer counter W
TCW
R/W
H'00
H'FFB3
Clock stop register 2
CKSTP2
R/W
H'FF
H'FFFB
Port mode register 3
PMR3
R/W
H'00
H'FFCA
9.6.2
Register Descriptions
1. Timer control/status register W (TCSRW)
Bit
Initial value
Read/Write
7
B6WI
1
R
6
TCWE
0
R/W
5
B4WI
1
R
4
TCSRWE
0
R/W
3
B2WI
1
R
0
WRST
0
R/W
2
WDON
0
R/W
1
B0WI
1
R
*
Note:
*
*
*
*
Write is permitted only under certain conditions, which are given in the descriptions of
the individual bits.
TCSRW is an 8-bit read/write register that controls write access to TCW and TCSRW itself,
controls watchdog timer operations, and indicates operating status.
Bit 7: Bit 6 write inhibit (B6WI)
Bit 7 controls the writing of data to bit 6 in TCSRW.
Bit 7
B6WI
Description
0
Bit 6 is write-enabled
1
Bit 6 is write-protected
(initial value)
This bit is always read as 1. Data written to this bit is not stored.