rt-thread-official/bsp/loongson/ls1cdev/libraries/ls1c_delay.c

/*
 * Copyright (c) 2006-2018, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2017-09-06     <EFBFBD><EFBFBD>Ϊ<EFBFBD><EFBFBD>       first version
 */


#include "ls1c_clock.h"




/*
 * <EFBFBD><EFBFBD>ʱָ<EFBFBD><EFBFBD>ʱ<EFBFBD>䣬<EFBFBD><EFBFBD>λms
 * @j <EFBFBD><EFBFBD>ʱʱ<EFBFBD>䣬<EFBFBD><EFBFBD>λms
 */
void delay_ms(int j)
{
    int k_max = clk_get_cpu_rate()/1000/92;  // <20><><EFBFBD><EFBFBD>1000<30><30>ʾms<6D><73><EFBFBD><EFBFBD><EFBFBD><EFBFBD>һ<EFBFBD><D2BB><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ϊʵ<CEAA><CAB5><EFBFBD><EFBFBD><EFBFBD>õľ<C3B5><C4BE><EFBFBD>ֵ
    int k = k_max;

    for ( ; j > 0; j--)
    {
        for (k = k_max; k > 0; k--)
        {
            __asm__ ("nop");        // ע<>⣬<EFBFBD><E2A3AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>࣬<EFBFBD><E0A3AC><EFBFBD><EFBFBD><EFBFBD>ᱻ<EFBFBD>Ż<EFBFBD><C5BB><EFBFBD>
        }
    }

    return ;
}


/*
 * <EFBFBD><EFBFBD>ʱָ<EFBFBD><EFBFBD>ʱ<EFBFBD>䣬<EFBFBD><EFBFBD>λus
 * @n <EFBFBD><EFBFBD>ʱʱ<EFBFBD>䣬<EFBFBD><EFBFBD>λus
 */
void delay_us(int n)
{
    int count_1us = 252000000 / 1000000 / 84;           // <20><>ʱ1us<75><73>ѭ<EFBFBD><D1AD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
                    // 252000000ΪcpuƵ<75>ʣ<EFBFBD><CAA3><EFBFBD><EFBFBD><EFBFBD>1000000<30><30>ʾ<EFBFBD><CABE>ʱ<EFBFBD><CAB1>λΪus<75><73>92Ϊʵ<CEAA><CAB5><EFBFBD><EFBFBD><EFBFBD>õľ<C3B5><C4BE><EFBFBD>ֵ
    int count_max;                                      // <20><>ʱn΢<6E><CEA2><EFBFBD><EFBFBD>ѭ<EFBFBD><D1AD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
    int tmp;

    // ΢<><CEA2>
    count_max = n * count_1us;
    if (10 >= n)                // <=10us
    {
        count_max = count_max / 3;
    }
    else if (100 >= n)          // <= 100us
    {
        count_max = count_max - count_max / 5;
    }
    else                        // > 100us
    {
        count_max = count_max - count_max / 10;
    }

    // <20><>ʱ
    for (tmp = count_max; tmp > 0; tmp--)
    {
        __asm__ ("nop");        // ע<>⣬<EFBFBD><E2A3AC><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>࣬<EFBFBD><E0A3AC><EFBFBD><EFBFBD><EFBFBD>ᱻ<EFBFBD>Ż<EFBFBD><C5BB><EFBFBD>            
    }

    return ;
}


/*
 * <EFBFBD><EFBFBD>ʱָ<EFBFBD><EFBFBD>ʱ<EFBFBD>䣬<EFBFBD><EFBFBD>λs
 * @i <EFBFBD><EFBFBD>ʱʱ<EFBFBD>䣬<EFBFBD><EFBFBD>λs
 */
void delay_s(int i)
{
    for ( ; i > 0; i--)
    {
        delay_ms(1000);
    }

    return ;
}