Z8F16800144ZCOG Zilog, Z8F16800144ZCOG Datasheet - Page 153

• Manufacturer Part Number: Z8F16800144ZCOG
• Description: KIT DEV FOR Z8F642 MCU 44 PIN
• Manufacturer: Zilog
• Series: Z8 Encore!®r
• Type: MCUr

Specifications of Z8F16800144ZCOG

• Contents: Hardware, Software and Documentation
• For Use With/related Products: Z8F642
• For Use With: 269-4661 - KIT ACC ETHERNET SMART CABLE
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 269-4678

Watchdog Timer Register Definitions
PS025011-1010
Watchdog Timer Reload Unlock Sequence
Watchdog Timer Reload High and Low Byte Registers
WDT Reset in STOP Mode
If enabled in STOP mode and configured to generate a Reset when a timeout occurs and
the device is in STOP mode, the WDT initiates a Stop Mode Recovery. Both the WDT 
status bit and the STOP bit in
STOP mode. For more information, see
Detection
Writing the unlock sequence to the Watchdog Timer Reload High (WDTH) register
address unlocks the two Watchdog Timer Reload registers (WDTH and WDTL) 
to allow changes to the timeout period. These write operations to the WDTH register
address produce no effect on the bits in the WDTH register. The locking mechanism
prevents unwarranted writes to the Reload registers. The following sequence is 
required to unlock the Watchdog Timer Reload registers (WDTH and WDTL) for 
write access.
1. Write
2. Write
3. Write the desired value to the Watchdog Timer Reload High register (WDTH).
4. Write the desired value to the Watchdog Timer Reload Low register (WDTL).
All steps of the WDT Reload Unlock sequence must be written in the order as listed
above. The value in the WDT Reload registers is loaded into the counter every time 
a
The two Watchdog Timer Reload registers (WDTH and WDTL) are described in the
following tables.
The Watchdog Timer Reload High and Low Byte (WDTH, WDTL) registers 
(see
the Watchdog Timer when a
{
sequence sets the desired Reload Value. Reading from these registers returns 
the current WDT count value.
WDTH[7:0]
WDT
Table 81
instruction is executed.
on page 33.
55H
AAH
,
and
WDTL[7:0]
to the Watchdog Timer Reload High register (WDTH).
to the Watchdog Timer Reload High register (WDTH).
Table 82
}. Writing to these registers following the unlock 
on page 140) form the 16-bit reload value that is loaded into
P R E L I M I N A R Y
WDT
Table 11
instruction executes. The 16-bit reload value is
on page 42 are set to 1 following WDT timeout in
Reset, Stop Mode Recovery, and Low-Voltage
Z8 Encore! XP
Product Specification
®
F1680 Series
Watchdog Timer
139