为什么timer1计数pic18l25k50中的三倍脉冲数显示正确

嗨，我正在处理PIC18L25K50设备，MPLAB 3.30和XC8 v1.33。我正在使用定时器1来测量到达引脚SOSCI(RC1)的脉冲数量，我设置定时器1如下：当我需要计数脉冲时，我重置定时器1，然后打开它，然后在另一个定时器的帮助下等待一秒钟理论上，例如，当脉冲频率在1秒内为10Hz时，应该对10个脉冲进行计数，但测量值为30。（TMR1=30）而且我总是得到测量值的三倍（20Hz，TMR1是60等）我测量的时间数据采集1秒，而且它是正确的，振荡频率也是好的（Fosc）。使用RRUTT。有什么想法或建议吗？谢谢你



      以下为原文

    Hi.

I'm working with the PIC18L25K50 device, MPLAB 3.30 and XC8 v1.33.

I'm using the timer1 to measure the number of pulses arriving at pin SOSCI (RC1)

I set the timer 1 as follows:

T1GCON = 0x00;
T1CON = 0x8E;
/*
TMR1CS<1:0>: = b'10' // Crystal oscillator on SOSCI/SOSCO pins
T1CKPS<1:0>: = b'00' // 1:1 Prescale value = 1
SOSCEN: 1 // Dedicated secondary oscillator circuit enabled
T1SYNC: 1 // Do not synchronize external clock input
RD16: 1// Enables register read/write of Timer1 in one 16-bit operation
TMRxON: 0 // TMR1 turn off
*/

When I need to count the pulses I reset the timer1, and turn on it then I wait one second with the help of another timer as follows:


TMR1 = 0x00;

T1CONbits.TMR1ON = 1;
// and wait 1 second
/******/
....
/*****/
//When one second has passed, I get the counter pulses in TMR1
//
MyPulses = TMR1
T1CONbits.TMR1ON = 0;



In theory, for example, when the pulse frequency is 10 Hz in a 1 second, 10 pulses should be counted

But the measured value is 30. (TMR1 = 30)

And I always get three times the measured value (20Hz, TMR1 is 60, etc)

I measured time data acquisition of 1 second and it's correct also the oscillation frequency is OK (Fosc).

I have read that there is an errata regarding the TMR1/3 but is only applicable when the timer1/3 overflow interrupt is used.

Any ideas or suggestions?

Thank you