Chapter 21 general purpose timer module (gpt), 1 introduction, 2 features – Freescale Semiconductor ColdFire MCF52210 User Manual
Page 339: Chapter 21, General purpose timer module (gpt), 1 introduction -1 21.2 features -1
MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2
Freescale Semiconductor
21-1
Chapter 21
General Purpose Timer Module (GPT)
21.1
Introduction
This device has one 4-channel general purpose timer module (GPT). It consists of a 16-bit counter driven
by a 7-stage programmable prescaler.
A timer overflow function allows software to extend the timing capability of the system beyond the 16-bit
range of the counter. Each of the four timer channels can be configured for input capture, which can
capture the time of a selected transition edge, or for output compare, which can generate output waveforms
and timer software delays. These functions allow simultaneous input waveform measurements and output
waveform generation.
Additionally, channel 3 can be configured as a 16-bit pulse accumulator that can operate as a simple event
counter or as a gated time accumulator. The pulse accumulator uses the GPT channel 3 input/output pin in
event mode or gated time accumulation mode.
21.2
Features
Features of the general-purpose timer include the following:
•
Four 16-bit input capture/output compare channels
•
16-bit architecture
•
Programmable prescaler
•
Pulse-widths variable from microseconds to seconds
•
Single 16-bit pulse accumulator
•
Toggle-on-overflow feature for pulse-width modulator (PWM) generation
•
External timer clock input (SYNCA/SYNCB)