Z8F082ASH020SC datasheet(140/244 Pages) ZILOG

140 / 244 page

PS024705-0405

P R E L I M I N A R Y

Comparator

Z8 Encore! XP® F08xA Series

Product Specification

122

Comparator

Overview

The Z8 Encore! XP® F08xA Series devices feature a general purpose comparator that

compares two analog input signals. A GPIO (CINP) pin provides the positive comparator

input. The negative input (CINN) may be taken from either an external GPIO pin or an

internal reference. The output is available as an interrupt source or can be routed to an

external pin using the GPIO multiplex. Features include:

• 2 inputs which can be connected up using the GPIO multiplex (MUX)

• 1 input can be connected to a programmable internal reference

• 1 input can be connected to the on-chip temperature sensor

• Output can be either an interrupt source or an output to an external pin

Operation

One of the comparator inputs may be connected to an internal reference which is a user

selectable reference that is user programmable with 200 mV resolution.

The comparator may be powered down to save on supply current. See the Power Control

on page 29 for details.

Because of the propagation delay of the comparator, it is not recommended to enable the

comparator without first disabling interrupts and waiting for the comparator output to

settle. Doing so can result in spurious interrupts after comparator enabling. The follow-

ing example shows how to safely enable the comparator:

ld cmp0

nop

; wait for output to settle

clr irq0 ; clear any spurious interrupts pending

Caution:

Z8F082ASH020SC Datasheet(PDF) 140 Page - Zilog, Inc.