Operation In Tod Single-Shot Output Mode (Without Correction Function) - Mitsubishi Electric M32R Series User Manual

Mitsubishi 32-bit risc single-chip microcomputers

Table of Contents

10.8.11 Operation in TOD Single-shot Output Mode (without Correction Function)

(1) Outline of TOD single-shot output mode

In single-shot output mode, the timer generates a pulse in width of (reload 0 register set value +

1) only once and stops without performing any operation.

When after setting the reload 0 register, the timer is enabled (by writing to the enable bit in

software or by TID1 underflow/overflow signal), it loads the content of reload 0 register into the

counter synchronously with the count clock, letting the counter start counting. The counter counts

down clock pulses and stops when it underflows after reaching the minimum count.

The F/F output waveform in single-shot output mode is inverted (F/F output levels change from

low to high, or vice versa) at startup and upon underflow, generating a single-shot pulse

waveform in width of (reload 0 register set value + 1) only once. Also, an interrupt can be

generated when the counter underflows.

The count value is (reload 0 register set value + 1). (For details about count operation, also refer

to Section 10.3.11, "Operation in TOP Single-shot Output Mode (with Correction Function)."

(2) Precautions to be observed when using TOD single-shot output mode

The following describes precautions to be observed when using TOD single-shot output mode.

• If the counter stops due to underflow in the same clock period as the timer is enabled by

external input, the former has priority (so that the counter stops).

• If the counter stops due to underflow in the same clock period as count is enabled by writing to

the enable bit, the latter has priority (so that countis enabled).

• If the timer is enabled by external input in the same clock period as count is disabled by writing

to the enable bit, the latter has priority (so that count is disabled).

• Because the internal circuit operation is synchronized to the count clock (prescaler output), a

finite time equal to a prescaler delay is included before F/F starts operating after the timer is

10.8 TOD (Output-related 16-bit Timer)

MULTIJUNCTION TIMERS