Operation In Top Delayed Single-Shot Output Mode (With Correction Function) - Mitsubishi Electric M32R Series User Manual

Mitsubishi 32-bit risc single-chip microcomputers

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10.3.10 Operation in TOP Delayed Single-shot Output Mode (With Correction Function)

(1) Outline of TOP delayed single-shot output mode

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

value + 1) only once, with the output delayed by an amount of time equal to (counter set value +

1) and then stops without performing any operation.

When after setting the counter and reload register, the timer is enabled (by writing to the enable

bit in software or by external input), it starts counting down from the counter's set value

synchronously with the count clock. The first time the counter underflows, the reload register

value is loaded into the counter causing it to continue counting down, and the counter stops when

it underflows next time.

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

change from low to high, or vice versa) when the counter underflows first time and next,

generating a single-shot pulse waveform in width of (reload register set value + 1) only once, with

the output delayed by an amount of time equal to (first set value of counter + 1). Also, an interrupt

can be generated when the counter underflows first time and next.

The valid count values are the (counter set value + 1) and (reload register set value + 1). The

diagram below shows timer operation as an example when the initial counter value = 4 and the

initial reload register value = 5.

Prescaler delay

Note 1: What you actually see in the cycle immediately after enable is the previous counter value, and not 4.

Note 2: What you actually see in the cycle immediately after reload is H'FFFF (underflow value), and not 5.

Note 3: This diagram does not show detail timing information.

Figure 10.3.15 Example of Counting in TOP Delayed Single-shot Output Mode

Count value =(4+1)+(5+1)=11

10.3 TOP (Output-related 16-bit Timer)

MULTIJUNCTION TIMERS