INT3测量频率信号问题 | 已解决，用 CCP 模块测量

神***

可以

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jm***

gj*** 发表于 2023-12-25 17:01
stc8h可以用Timer3+int1来测量高电平脉冲宽度吗？

Timer3 can only be used with some limitations.

The best hardware HI-LEVEL measurement is a gated time, like T0,T1.
With GATE the count stops, when the pin is LOW.

Next best HW is a CAPTURE timer, where the pin edge gets the timer value at that instant.
You get two captures and take the difference.

Timer3 has no GATE and no capture, so you would need to use INT1 to SW start/stop/read/clear timer3. That Sw solution has more jitter, and needs a high priority interrupt.

STC8H does have TM3PS register, so T3.CLK = SysCLK/(TM3PS+1) which can nicely scale the 16 bits timer read value.