看完这个两个图,我们知道xs128要使用脉冲计数,必须使用pt7!!
16-Bit Pulse Accumulator Control Register (PACTL
When PAEN is set, the PACT is enabled.The PACT shares the input pin with IOC7.
要注意的是这里的paen要置1,同时脉冲输入口,要接入到ioc7也就是说pt7接口
详细解释下:
6 PAEN
Pulse Accumulator System Enable — PAEN is independent from TEN. With timer disabled, the pulse accumulator can function unless pulse accumulator is disabled.
0 16-Bit Pulse Accumulator system disabled.
1 Pulse Accumulator system enabled.
打开脉冲计数,需要
5 PAMOD
Pulse Accumulator Mode — This bit is active only when the Pulse Accumulator is enabled (PAEN = 1).
0 Event counter mode.
事件触发计数 也就是外面有脉冲来就计数,需要
1 Gated time accumulation mode. 门控时间累加方式。简单的说就是统计输入脚的高或低电平持续的时间clock数目。
4 PEDGE
Pulse Accumulator Edge Control—This bit is active only when the Pulse Accumulator is enabled (PAEN = 1).
For PAMOD bit = 0 (event counter mode). See Table 16-18.
0 Falling edges on IOC7 pin cause the count to be incremented.
下降沿
1 Rising edges on IOC7 pin cause the count to be incremented.
上升沿 这个无所谓了。
3:2
CLK[1:0]
Clock Select Bits — Refer to Table 16-19. 门控时间计数方式有效。
1 PAOVI
Pulse Accumulator Overflow Interrupt Enable
0 Interrupt inhibited.
1 Interrupt requested if PAOVF is set.
溢出中断是否有效
0 PAI
Pulse Accumulator Input Interrupt Enable
0 Interrupt inhibited.
1 Interrupt requested if PAIF is set. 输入中断是否有效
明白上述各种含义代码如下 代码如下:
代码简单,道理难懂。
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