Z8F2402 datasheet(49/246 Pages) ZILOG

49 / 246 page

Z8F640x/Z8F480x/Z8F320x/Z8F240x/Z8F160x

Z8 Encore!®

PS017610-0404

Low-Power Modes

Overview

The Z8F640x family 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 the

Halt mode.

Stop Mode

Execution of the eZ8 CPU’s STOP instruction places the Z8F640x family device into Stop

mode. In Stop mode, the operating characteristics are:

•

Primary crystal oscillator is stopped

•

System clock is stopped

•

eZ8 CPU is stopped

•

Program counter (PC) stops incrementing

•

Watch-Dog Timer’s internal RC oscillator continues to operate

•

If enabled, the Watch-Dog Timer continues to operate

•

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 (VCC or GND). The Z8F640x family device can be

brought out of Stop mode using Stop Mode Recovery. For more information on STOP

Mode Recovery refer to the Reset and Stop Mode Recovery chapter.

Halt Mode

Execution of the eZ8 CPU’s HALT instruction places the Z8F640x family device into Halt

mode. In Halt mode, the operating characteristics are:

•

Primary crystal oscillator is enabled and continues to operate

•

System clock is enabled and continues to operate

•

eZ8 CPU is idle

•

Program counter (PC) stops incrementing

Z8F2402 Datasheet(PDF) 49 Page - Zilog, Inc.