Z8F4822AR020SG Datasheet, PDF (54/323 Pages) Zilog, Inc. – High Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F64xx Series
Product Specification
34
Low-Power Modes
The Z8 Encore! XP F64xx Series products contain power-saving features. The highest
level of power reduction is provided by STOP Mode. The next level of power reduction is
provided by HALT Mode.
STOP Mode
Execution of the eZ8 CPU’s stop instruction places the device into STOP Mode. In STOP
Mode, the operating characteristics are:
• Primary crystal oscillator is stopped; the X_IN pin is driven High and the X_OUT pin is
driven Low
• System clock is stopped
• eZ8 CPU is stopped
• Program counter (PC) stops incrementing
• The Watchdog Timer and its internal RC oscillator continue to operate, if enabled for
operation during STOP Mode
• The Voltage Brown-Out protection circuit continues to operate, if enabled for operation
in STOP Mode using the associated option bit
• All other on-chip peripherals are idle
To minimize current in STOP Mode, all GPIO pins that are configured as digital inputs
must be driven to one of the supply rails (V_CC or GND), the Voltage Brown-Out protection
must be disabled, and the Watchdog Timer must be disabled. The devices can be brought
out of STOP Mode using Stop Mode Recovery. For more information about Stop Mode
Recovery, see the Reset and Stop Mode Recovery chapter on page 28.
Caution: STOP Mode must not be used when driving the Z8 Encore! XP F64xx Series devices
with an external clock driver source.
PS019924-0113
PRELIMINARY
Low-Power Modes