HD6433640 HITACHI [Hitachi Semiconductor], HD6433640 Datasheet - Page 282

• Manufacturer Part Number: HD6433640
• Description: H8/3644 Series Hardware Manual
• Manufacturer: HITACHI [Hitachi Semiconductor]

Register Configuration
Table 9.20 shows the register configuration of the watchdog timer.
Table 9.20
Name
Timer control/status register W
Timer counter W
9.6.2
Timer Control/Status Register W (TCSRW)
Note: * Write is permitted only under certain conditions, which are given in the descriptions of the
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.
This bit is always read as 1. Data written to this bit is not stored.
Bit 7: B6WI
0
1
Bit 6—Timer Counter W Write Enable (TCWE): Bit 6 controls the writing of data to bit 8 to
TCW.
Bit 6: TCWE
0
1
274
Bit
Initial value
Read/Write
individual bits.
Register Descriptions
Watchdog Timer Registers
B6WI
Description
Bit 6 is write-enabled
Bit 6 is write-protected
Description
Data cannot be written to TCW
Data can be written to TCW
R
7
1
TCWE
R/(W)*
6
0
Abbrev.
TCSRW
TCW
B4WI
R
5
1
TCSRWE
R/(W)*
4
0
R/W
R/W
R/W
B2WI
R
3
1
Initial Value
H'AA
H'00
WDON
R/(W)*
2
0
B0WI
Address
H'FFBE
H'FFBF
R
1
1
(initial value)
(initial value)
WRST
R/(W)*
0
0