eZ80L92 MCU
Product Specification
73
Watchdog Timer
The Watchdog Timer (WDT) helps protect against corrupt or unreliable software, power
faults, and other system-level problems which may place the eZ80 CPU into unsuitable
operating states. The ZLP12840 MCU WDT features:
•
•
Four programmable time-out periods: 218, 222, 225, and 227 clock cycles
Two selectable WDT clock sources: the system clock or the real time clock source
(on-chip 32 kHz crystal oscillator or 50/60 Hz signal)
•
•
A selectable time-out response: a time-out can be configured to generate either a
RESET or a non-maskable interrupt (NMI)
A WDT time-out RESET indicator flag
Figure 17 illustrates the block diagram for the Watchdog Timer.
Data[7:0]
Control Register/
Reset Register
WDT_CLK
RTC Clock
28-Bit
WDT Control Logic
Upcounter
System Clock
Time-Out Compare Logic
{WDT_PERIOD}
RESET
NMI to eZ80 CPU
Figure 17. Watchdog Timer Block Diagram
PS013015-0316
Watchdog Timer
ZILOG [ ZILOG, INC. ]
