Z8F1680SH020SG Datasheet, PDF (67/412 Pages) Zilog, Inc. – High-Performance 8-Bit Microcontrollers

Z8 Encore! XP^® F1680 Series
Product Specification
42
Chapter 6. Low-Power Modes
The Z8 Encore! XP F1680 Series products have power-saving features. The highest level
of power reduction is provided by the STOP Mode. The next lower level of power reduc-
tion is provided by the HALT Mode.
Further power savings can be implemented by disabling individual peripheral blocks
while in NORMAL Mode.
6.1.
STOP Mode
Executing the eZ8 CPU’s Stop instruction places the device into STOP Mode. In STOP
Mode, the operating characteristics are:
• Primary crystal oscillator and internal precision oscillator are stopped; XIN and XOUT 
(if previously enabled) are disabled and PA0/PA1 reverts to the states programmed by
the GPIO registers
• System clock is stopped
• eZ8 CPU is stopped
• Program counter (PC) stops incrementing
• Watchdog Timer’s internal RC oscillator continues operating if enabled by the Oscil-
lator Control Register
• If enabled, the Watchdog Timer (WDT) logic continues operating
• If enabled, the 32 kHz secondary oscillator continues operating
• If enabled for operation in STOP Mode, the Timer logic continues to operate with
32 kHz secondary oscillator as the Timer clock source
• If enabled for operation in STOP Mode by the associated Flash option bit, the VBO
protection circuit continues operating; the low-voltage detection circuit continues to
operate if enabled by the Power Control Register
• Low-Power Operational Amplifier and comparator continue to operate if enabled by
the Power Control Register
• All other on-chip peripherals are idle
PS025015-1212
PRELIMINARY
Low-Power Modes