Z8F042AHJ020SC00TR Zilog, Z8F042AHJ020SC00TR Datasheet - Page 105

• Manufacturer Part Number: Z8F042AHJ020SC00TR
• Description: IC ENCORE XP MCU FLASH 4K 28SSOP
• Manufacturer: Zilog
• Series: Encore!® XP®r

Specifications of Z8F042AHJ020SC00TR

• Core Processor: Z8
• Core Size: 8-Bit
• Speed: 20MHz
• Connectivity: IrDA, UART/USART
• Peripherals: Brown-out Detect/Reset, LED, LVD, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 23
• Program Memory Size: 4KB (4K x 8)
• Program Memory Type: FLASH
• Eeprom Size: 128 x 8
• Ram Size: 1K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 28-SSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: Z8F042AHJ020SC00T

Table 57. Watchdog Timer Control Register (WDTCTL)
Watchdog Timer Control Register Definitions
BITS
FIELD
RESET
R/W
ADDR
X = Undefined.
PS022825-0908
Note:
Watchdog Timer Control Register
Watchdog Timer Reload Upper, High and Low Byte Registers
W
7
X
Watchdog Timer Reload Registers results in a one-second timeout at room temperature
and 3.3 V supply voltage.
Timeouts other than one second may be obtained by scaling the calibration values up or
down as required.
The Watchdog Timer accuracy still degrades as temperature and supply voltage vary. See
Table 133
The Watchdog Timer Control (WDTCTL) register is a write-only control register. Writing
the
dog Timer Reload Byte registers (WDTU, WDTH, and WDTL) to allow changes to the
time-out period. These write operations to the WDTCTL register address produce no
effect on the bits in the WDTCTL register. The locking mechanism prevents spurious
writes to the Reload registers.
This register address is shared with the read-only Reset Status register.
WDTUNLK—Watchdog Timer Unlock
The software must write the correct unlocking sequence to this register before it is allowed
to modify the contents of the Watchdog Timer reload registers.
The Watchdog Timer Reload Upper, High and Low Byte (WDTU, WDTH, WDTL) regis-
ters
dog Timer when a WDT instruction executes. The 24-bit reload value is {WDTU[7:0],
WDTH[7:0], WDTL[7:0]}. Writing to these registers sets the appropriate Reload Value.
Reading from these registers returns the current Watchdog Timer count value.
55H
(Table 58
,
AAH
on page 230 for details.
W
X
6
unlock sequence to the WDTCTL register address unlocks the three Watch-
through
Table
W
X
5
60) form the 24-bit reload value that is loaded into the Watch-
W
X
4
WDTUNLK
FF0H
W
X
3
Z8 Encore! XP
W
X
2
Product Specification
W
X
1
®
F082A Series
Watchdog Timer
W
X
0
94