ST72361 datasheet(93/224 Pages) STMICROELECTRONICS

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ST72361

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8-BIT TIMER (Cont’d)

Whatever the timer mode used (input capture, out-

put compare, one pulse mode or PWM mode) an

overflow occurs when the counter rolls over from

FFh to 00h then:

– The TOF bit of the SR register is set.

– A timer interrupt is generated if:

– TOIE bit of the CR1 register is set and

– I bit of the CC register is cleared.

If one of these conditions is false, the interrupt re-

mains pending to be issued as soon as they are

both true.

Clearing the overflow interrupt request is done in

two steps:

1. Reading the SR register while the TOF bit is set.

2. An access (read or write) to the CTR register.

Notes: The TOF bit is not cleared by accesses to

ACTR register. The advantage of accessing the

ACTR register rather than the CTR register is that

it allows simultaneous use of the overflow function

and reading the free running counter at random

times (for example, to measure elapsed time) with-

out the risk of clearing the TOF bit erroneously.

The timer is not affected by WAIT mode.

In HALT mode, the counter stops counting until the

mode is exited. Counting then resumes from the

previous count (MCU awakened by an interrupt) or

from the reset count (MCU awakened by a Reset).

ST72361 数据表(PDF) 93 Page - STMicroelectronics