Datasheet

Section 16 Watchdog Timer
Rev. 2.00 Jul. 04, 2007 Page 337 of 692
REJ09B0309-0200
16.2.1 Timer Control/Status Register WD1 (TCSRWD1)
TCSRWD1 performs the TCSRWD1 and TCWD write control. TCSRWD1 also controls the
watchdog timer operation and indicates the operating state. TCSRWD1 must be rewritten by using
the MOV instruction. The bit manipulation instruction cannot be used to change the setting value.
Bit Bit Name
Initial
Value
R/W Description
7 B6WI 1 R/W Bit 6 Write Inhibit
The TCWE bit can be written only when the write value of
the B6WI bit is 0.
This bit is always read as 1.
6 TCWE 0 R/W Timer Counter WD Write Enable
TCWD can be written when the TCWE bit is set to 1.
When writing data to this bit, the write value for bit 7 must
be 0.
5 B4WI 1 R/W Bit 4 Write Inhibit
The TCSRWE bit can be written only when the write
value of the B4WI bit is 0. This bit is always read as 1.
4 TCSRWE 0 R/W Timer Control/Status Register WD Write Enable
The WDON and WRST bits can be written when the
TCSRWE bit is set to 1.
When writing data to this bit, the write value for bit 5 must
be 0.
3 B2WI 1 R/W Bit 2 Write Inhibit
The WDON bit can be written only when the write value
of the B2WI bit is 0. This bit is always read as 1.