HT85F2270 datasheet(128/226 Pages) HOLTEK

128 / 226 page

Rev. 1.00

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Standard 8051 8-Bit Flash MCU

HT85F2260/HT85F2270/HT85F2280

28 Timer/Event Counters 0, 1, 3

These three timers provide have a similar type and structure and operate with a choice of three

modes for Timers 1 and 3 and four modes for Timer 0. They provide basic timing and event

counting operations.

Introduction

The different operating modes of the timers are selected using the TnM1 and TnM0 bits in the

TMOD or T3CON register.

Timer Mode

TnM1, TnM0 bits

Mode Name

Application Timer

1�-bit Timer-Counter

Timer 0� 1� �

16-bit Counter

Timer 0� 1� �

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8-bit Counter Auto Reload

Timer 0� 1� �

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Two 8-bit Counters

Timer 0 onl�

The registers, THn and TLn, are special function registers located in the Special Function Registers

and is the place where the actual timer value is stored. This register pair, are each 8-bit wide, and

can be cascaded into 13-bit or 16-bit wide using mode options. The value in the timer registers

increases by one each time an internal clock pulse is received or an external transition occurs on

the external timer pin. The timer will count from the initial value loaded by the preload register to

their full count at which point the timer overflows and an internal interrupt signal is generated. If

the timer auto-reload mode is selected, the timer value will then be reset with the initial preload

achieve a maximum full range count, the preload register must first be cleared to all zeros.

HT85F2270 Datasheet(PDF) 128 Page - Holtek Semiconductor Inc