Z8F082ASH020SC datasheet(37/244 Pages) ZILOG

37 / 244 page

PS024705-0405

P R E L I M I N A R Y

Reset and STOP Mode Recovery

Z8 Encore! XP® F08xA Series

Product Specification

Reset and STOP Mode Recovery

Overview

The Reset Controller within the Z8 Encore! XP® F08xA Series controls Reset and STOP

Mode Recovery operation and provides indication of low supply voltage conditions. In

typical operation, the following events cause a Reset:

• Power-On Reset (POR)

• Voltage Brown-Out (VBO)

• Watch-Dog Timer time-out (when configured by the WDT_RES Flash Option Bit to

initiate a reset)

• External RESET pin assertion (when the alternate RESET function is enabled by the

GPIO register)

• On-Chip Debugger initiated Reset (OCDCTL[0] set to 1)

When the device is in STOP mode, a STOP Mode Recovery is initiated by either of the

following:

• Watch-Dog Timer time-out

• GPIO Port input pin transition on an enabled STOP Mode Recovery source

Reset Types

The Z8 Encore! XP® F08xA Series provides several different types of Reset operation.

STOP Mode Recovery is considered a form of Reset. Table 8 lists the types of Reset and

their operating characteristics. The System Reset is longer if the external crystal oscillator

is enabled by the Flash option bits, allowing additional time for oscillator start-up.

Table 8. Reset and STOP Mode Recovery Characteristics and Latency

Reset Type

Reset Characteristics and Latency

Control Registers

eZ8

CPU

Reset Latency (Delay)

System Reset

Reset (as applicable)

Reset 66 Internal Precision Oscillator Cycles

System Reset with Crystal

Oscillator Enabled

Reset (as applicable)

Reset 5000 Internal Precision Oscillator Cycles

Z8F082ASH020SC Datasheet(PDF) 37 Page - Zilog, Inc.