Z8F1680SH020SG Datasheet, PDF (63/412 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F1680 Series
Product Specification
38
reconfigure the oscillator control block such that the correct system clock source is
enabled and selected.
The eZ8 CPU fetches the Reset vector at Program Memory addresses 0002H and 0003H
and loads that value into the Program Counter. Program execution begins at the Reset
vector address. Following Stop Mode Recovery, the stop bit in the Reset Status Register is
set to 1. Table 11 lists the Stop Mode Recovery sources and resulting actions. The text
following provides more detailed information about each of the Stop Mode Recovery
sources.
Table 11. Stop Mode Recovery Sources and Resulting Action
Operating
Mode
STOP Mode
Stop Mode Recovery Source
Action
Watchdog Timer time-out when configured Stop Mode Recovery
for Reset
Watchdog Timer time-out when configured Stop Mode Recovery followed by interrupt
for interrupt
(if interrupts are enabled)
Interrupt from Timer enabled for STOP
Mode operation
Stop Mode Recovery followed by interrupt
(if interrupts are enabled)
Interrupt from Comparator enabled for
STOP Mode operation
Stop Mode Recovery followed by interrupt
(if interrupts are enabled)
Data transition on any GPIO port pin
Stop Mode Recovery
enabled as a Stop Mode Recovery source
Assertion of external RESET Pin
System Reset
Debug Pin driven Low
System Reset
5.3.1. Stop Mode Recovery Using Watchdog Timer Time-Out
If the WDT times out during STOP Mode, the device undergoes a Stop Mode Recovery
sequence. In the Reset Status Register, the WDT and stop bits are set to 1. If the WDT is
configured to generate an interrupt on time-out and the F1680 Series MCU is configured
to respond to interrupts. The eZ8 CPU services the WDT interrupt request following the
normal Stop Mode Recovery sequence.
5.3.2. Stop Mode Recovery Using Timer Interrupt
If a Timer with 32K crystal enabled for STOP Mode operation interrupts during STOP
Mode, the device undergoes a Stop Mode Recovery sequence. In the Reset Status Register,
the stop bit is set to 1. If the F1680 Series MCU is configured to respond to interrupts, the
PS025015-1212
P R E L I M I N A R Y Reset, Stop Mode Recovery and Low-Voltage