HT85F2270 datasheet(146/226 Pages) HOLTEK

146 / 226 page

Rev. 1.00

146 of ��6

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Standard 8051 8-Bit Flash MCU

HT85F2260/HT85F2270/HT85F2280

Capture Modes

Timer 2 has two capture modes, the Capture on Edge Mode, known as Capture Mode 0, and the

Capture on Write Mode, known as Capture Mode 1. The required mode is selected using the

COCAHn and COCALn bits in the CCEN register. The accompanying diagram illustrates the basic

operational blocks.

CCn

CRCH

CRCL

TH�

TL�

I�FR bit

COCAHn

COCALn

Write to CCLn(CRCL)

Capture �ode 1

Capture �ode 0

Note: 1. n=0~�

�. CC1~CC� capture input b� rising edge

�. CC0 capture input b� rising or falling edge selected b� the I�FR bit

4. Write to CCLn is for CC1~CC� and Write to CRCL is for CC0

Capture Modes Block Diagram

Capture On Edge Mode

To select this mode, bits COCAHn and COCALn in the CCEN register, should be set to “01”

respectively. In this mode, Modules 1~3 will capture the Timer 2 counter on the rising edge of an

external signal applied on the CC1~CC3 pins. Module 0 will capture the Timer 2 counter contents

on a rising or falling edge applied on the CC0 pin. The rising or falling edge trigger is controlled by

the I3FR bit in the T2CON register.

Capture On Write Mode

To select this mode, bits COCAHn and COCALn in the CCEN register, should be set to “11”

respectively. In this mode a Timer 2 Capture is generated by any write operation into the capture

contents will be latched into the appropriate capture registers.

HT85F2270 Datasheet(PDF) 146 Page - Holtek Semiconductor Inc