NEC µPD72257 Preliminary User's Manual page 117

System Controller
4.7.3.9
Access
Address
Initial Value
31 30 29 28
0 0 0 0
R R R R
15 14 13 12
0 0 0 0
R R R R
Bit Bit name
0 ADWAITZEN
SYSWDCTRL - System Watchdog control register
This register controls the operation of the System Watchdog.
This register can be read/written in 32-bit units.
<SysC_Base> + 28
H
0000 0000 . This register is initialized by any reset.
H
27 26 25 24
0 0 0
R R R
11 10 9
0 0 0
R R R
Writing to the read-only bits is ignored, reading returns undefined values.
Function
Controls the System Watchdog function
0 System Watchdog disabled
1 System Watchdog enabled
If the System Watchdog is enabled, it observes the ADBus Host-I/F signal
ADWAIT.
If ADWAIT is active, i.e. at low level, for more than 325 HCLK system clock periods,
the System Watchdog resets the controller.
Preliminary User's Manual S19203EE1V3UM00
23 22 21
0 0 0 0
R R R R
8 7 6 5
0 0 0 0
R R R R
Chapter 4
20 19 18 17
0 0 0 0
R R R R
4 3 2 1
0 0 0 0
R R R R
16
0
R
0
AD
WAIT
ZEN
R/W
117