DSP56303 datasheet(193/292 Pages) FREESCALE

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DSP56303 User’s Manual, Rev. 2

Freescale Semiconductor

9-1

Triple Timer Module

The timers in the DSP56303 internal triple timer module act as timed pulse generators or as

pulse-width modulators. Each timer has a single signal that can function as a GPIO signal or as a

timer signal. Each timer can also function as an event counter to capture an event or to measure

the width or period of a signal.

9.1 Overview

The timer module contains a common 21-bit prescaler and three independent and identical

general-purpose 24-bit timer/event counters, each with its own register set. Each timer has the

following capabilities:

Uses internal or external clocking

Interrupts the DSP56303 after a specified number of events (clocks) or signals an external

device after counting internal events

Triggers DMA transfers after a specified number of events (clocks) occurs

Connects to the external world through one bidirectional signal, designated

TIO[0– 2]

for timers 0–2.

When TIO is configured as an input, the timer functions as an external event counter or measures

external pulse width/signal period. When TIO is configured as an output, the timer functions as a

timer, a watchdog timer, or a pulse-width modulator. When the timer does not use TIO, it can be

used as a GPIO signal (also called TIO[0–2]).

9.1.1 Triple Timer Module Block Diagram

Figure 9-1 shows a block diagram of the triple timer module. This module includes a 24-bit

Timer Prescaler Load Register (TPLR), a 24-bit Timer Prescaler Count Register (TPCR), and

three timers. Each timer can use the prescaler clock as its clock source.

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