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7721 Group User’s Manual

TIMER A

8.1 Overview

8–2

8.1 Overview

Timer A consists of five counters, Timers A0 to A4, each equipped with a 16-bit reload function. Timers A0

to A4 operate independently of one another.

Timer A has four operating modes listed below. Timers A0 and A1 operate in the timer mode only. Timers

A2 to A4 have selective four operating modes listed below.

(1)

Timer mode (Timers A0 to A4)

The timer counts an internally generated count source. For Timers A2 to A4, the following functions

can be used in this mode:

•Gate function

•Pulse output function

(2)

Event counter mode (Timers A2 to A4)

The timer counts an external signal. The following functions can be used in this mode:

•Pulse output function

•Two-phase pulse signal processing function

(3)

One-shot pulse mode (Timers A2 to A4)

The timer outputs a pulse which has an arbitrary width once.

(4)

Pulse width modulation (PWM) mode (Timers A2 to A4)

Timer outputs pulses which have an arbitrary width in succession. The counter functions as one of

the following pulse width modulators:

•16-bit pulse width modulator

•8-bit pulse width modulator

In this chapter, Timer Ai (i = 0 to 4) indicates Timers A0 to A4. Timer Aj (j = 2 to 4) indicates Timers A2

to A4; this is applies when the timer A’s input/output pins are used etc. (Hereafter, input/output pins are

called I/O pins.)

7721 데이터시트(PDF) 121 Page - Renesas Technology Corp