Справочник Пользователя для Motorola MC68HC908MR16

Advance Information

MC68HC908MR16/MC68HC908MR32 — Rev. 4.0

226

Timer Interface B (TIMB)

MOTOROLA

12.2  Introduction

This section describes the timer interface module B (TIMB). The TIMB is 
a 2-channel timer that provides:

•

Timing reference with input capture

•

Output compare

•

Pulse-width modulation functions 

 is a block diagram of the TIMB.

Features of the TIMB include:

•

Two input capture/output compare channels:

–

Rising-edge, falling-edge, or any-edge input capture trigger

–

Set, clear, or toggle output compare action

•

Buffered and unbuffered pulse-width modulation (PWM) signal 
generation

•

Programmable TIMB clock input:

–

7-frequency internal bus clock prescaler selection

–

External TIMB clock input (4-MHz maximum frequency)

•

Free-running or modulo up-count operation

•

Toggle any channel pin on overflow

•

TIMB counter stop and reset bits

 shows the TIMB structure. The central component of the 

TIMB is the 16-bit TIMB counter that can operate as a free-running 
counter or a modulo up-counter. The TIMB counter provides the timing 
reference for the input capture and output compare functions. The TIMB 
counter modulo registers, TBMODH–TBMODL, control the modulo 
value of the TIMB counter. Software can read the TIMB counter value at 
any time without affecting the counting sequence.