z8f0822 ZiLOG Semiconductor, z8f0822 Datasheet - Page 57

• Manufacturer Part Number: z8f0822
• Description: High Performance 8-bit Microcontrollers
• Manufacturer: ZiLOG Semiconductor

PS022517-0508
Stop Mode Recovery Using WDT Time-Out
Stop Mode Recovery Using a GPIO Port Pin Transition
Caution:
If the WDT times out during STOP mode, the device undergoes a Stop Mode Recovery
sequence. In the WDT Control Register, the WDT and STOP bits are set to 1. If the WDT is
configured to generate an interrupt upon time-out and the Z8 Encore! XP
device is configured to respond to interrupts, the eZ8 CPU services the WDT interrupt
request following the normal Stop Mode Recovery sequence.
Each of the GPIO Port pins can be configured as a Stop Mode Recovery input source. On
any GPIO pin enabled as a STOP Mode Recover source, a change in the input pin value
(from High to Low or from Low to High) initiates Stop Mode Recovery. The GPIO Stop
Mode Recovery signals are filtered to reject pulses less than 10 ns (typical) in duration. In
the WDT Control Register, the STOP bit is set to 1.
In STOP mode, the GPIO Port Input Data Registers (PxIN) are disabled. The Port
Input Data Registers record the Port transition only if the signal stays on the Port
pin through the end of the Stop Mode Recovery delay. Therefore, short pulses on
the Port pin initiates Stop Mode Recovery without being written to the Port Input
Data Register or without initiating an interrupt (if enabled for that pin).
Z8 Encore! XP
Reset and Stop Mode Recovery
Product Specification
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F0822 Series
F0822 Series
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