x Mbed NUCLEO-F103RB Mbed2 リビジョン172

目的
ある意味タイマーのテスト

1000usの時は、64612カウントで
1000倍すると約64Mhz

参考



# include "mbed.h"

//Serial pc(SERIAL_TX, SERIAL_RX); //767
//RawSerial pc(PA_2, PA_3); //010
Serial pc(PA_9, PA_10); // tx, rx 103

int main()
{

    pc.printf("\r\n103\r\n"); //767

    pc.printf("1000us\r\n"); //767
    for (int ii=0;ii<5;ii++) {

        CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
        DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk;

        uint32_t startTime = DWT->CYCCNT;

        //DWT_CYCCNT
        wait_us(1000);

        uint32_t time = DWT->CYCCNT;

        pc.printf("%d\r\n",time-startTime); //767

        //1秒待つ
        wait_ms(1000);
    }//for

    pc.printf("2000us\r\n"); //767
    for (int ii=0;ii<5;ii++) {

        CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
        DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk;

        uint32_t startTime = DWT->CYCCNT;

        //DWT_CYCCNT
        wait_us(2000);

        uint32_t time = DWT->CYCCNT;

        pc.printf("%d\r\n",time-startTime); //767

        //1秒待つ
        wait_ms(1000);
    }//for


}//main

//容量削減
//void error(const char* format, ...){}