main.c

《嵌入式开发实例》全书所附源代码

//=============================================================================
// Filename:     main.c
//
// Description:  A sample driver application for the bootloader.
//
// Copyright (C) 2000 - 2002 Texas Instruments Incorporated
//
//============================================================================


#include "arm_boot.h"
#include "api_mem.h"
#include "dsp_proj_code.h"
#include "dsp_proj_data.h"
#include <stdio.h>

// ---------------------- Clock Setup --------------------------------
#define DSPCLK_ENABLE      0x00004000
#define MCLK_ENABLE        0x00008000

#define KBDIO_IO		   ((unsigned long *)0xFFFF2900)
#define KBDIO_CIO		   ((unsigned long *)0xFFFF2904)
#define KBDIO_EN  		   ((unsigned long *)0xFFFF2914)
#define KBDIO_IO1		   0x00000002



static unsigned long nandgpio( unsigned long *addr, unsigned long Data )
{
    unsigned long readback;
    
    readback = *addr;
   
    readback &= ~(Data);
    *addr = readback;

    return( readback );
}

static void EnableDSPCLK(void)
{  
    nandgpio(KBDIO_EN, DSPCLK_ENABLE);
}

static void EnableMCLK(void)
{  
    nandgpio(KBDIO_EN, MCLK_ENABLE);
}




// ---------------------- Main Driver --------------------------------


// Trigger a DSPINT interrupt on the DSP side
static void interrupt_dsp()
{
    volatile unsigned short *apic = (unsigned short *)0xffe40000;
    *apic |= 0x4;  // set bit 2 [DSPINT] of the API Control Register
}

// set up a structure to represent the DSP program and data to be loaded
#define PMST_VAL 0xFF88

static dsp_app_struct test_dsp_app = 
                           {dsp_proj_program, dsp_proj_data, PMST_VAL};

main()
{
    volatile unsigned short *dsp_running = (unsigned short *)DSP_RUNNING;
    volatile unsigned long  *dsp_input   = (unsigned long  *)DSP_INPUT;
    unsigned long num = 9;  // input to the DSP

    // disable all interrupts
    resetinterrupts();

    setupstacks();

    pll_init(44, 100);  // setup arm and dsp PLLs
    EnableMCLK();       // enable external arm clock
    EnableDSPCLK();     // enable dsp clkout

    // enable DSP_XF output on KBGPIO1
    nandgpio(KBDIO_CIO, KBDIO_IO1);
    nandgpio(KBDIO_EN, KBDIO_IO1);

    // The DSP is not yet running its main app
    Write_Short_API(dsp_running, 0);

    // load the DSP with the program and data
    if (dsp_load(&test_dsp_app) != LOAD_OK) {
        while (1) {
        }
    }

    setup_api_interrupt();

    // start the DSP
    dsp_start() ;

    // Make sure DSP is done bootloading: synchronize via an API flag
    while (*dsp_running == 0) {
    }

    Write_Long_API(dsp_input, num);

    // Trigger an API interrupt on the DSP
    interrupt_dsp();

    while(1) {
        if (factorial != 0xFFFFFFFF) {
            printf("Factorial of %d computed by the DSP is %d\n", 
                   num, factorial);
            break;
        }
    }
}