ad50.c

用DSP5410实现对音乐文件音量的限制性调节

/*
 *  Copyright 2003 by Texas Instruments Incorporated.
 *  All rights reserved. Property of Texas Instruments Incorporated.
 *  Restricted rights to use, duplicate or disclose this code are
 *  granted through contract.
 *  
 */
/* "@(#) DDK 1.11.00.00 11-04-03 (ddk-b13)" */
/* 
 *  ======== ad50.c ========
 */

#include <std.h>

#include <csl.h>
#include <csl_mcbsp.h>

#include <ad50.h>

static Void spWrite(MCBSP_Handle hMcbsp, Uns dataVal);
static Void codecControlWrite(MCBSP_Handle hMcbsp, Uns regVal, Uns dataVal);

/*
 *  ======== AD50_init ========
 */
#pragma CODE_SECTION(AD50_init, ".text:init")
Void AD50_init( Void )
{
}

/*
 *  ======== AD50_setParams ========
 */
Void AD50_setParams(MCBSP_Handle hMcbsp, AD50_Params *params)
{
    codecControlWrite(hMcbsp, 1, params->control1);
    codecControlWrite(hMcbsp, 2, params->control2);
    codecControlWrite(hMcbsp, 3, params->control3);
    codecControlWrite(hMcbsp, 4, params->control4);
}

/*
 *  ======== codecControlWrite ========
 *  The 16-bit word in each control register is composed of:
 *  b15-b8 -> register address to talk to 1 of 5 control registers
 *  b7-b0  -> data.
 */
static Void codecControlWrite(MCBSP_Handle hMcbsp, Uns regVal, Uns dataVal)
{
    Uns temp;
 
    temp = (regVal << 8) | (dataVal & 0x00ff);

    /* write '1' to put codec into command mode */
    spWrite(hMcbsp, 1);

    /* write the command */
    spWrite(hMcbsp, temp);
}

/*
 *  ======== spWrite ========
 *  WARNING!  Unbounded while loop!
 *  spWrite() should only be called during init time.
 */
static Void spWrite(MCBSP_Handle hMcbsp, Uns dataVal)
{
    while(!MCBSP_xrdy(hMcbsp)) {
        /* wait for TX ready */
    }

    MCBSP_write(hMcbsp, dataVal);
}