DSP课程课堂作业程序

				/*****************************************************************************/
				/* Codec.c */
				/* */
				/* Digital Loopback example */
				/* */
				/*************************************************************************** */
				
				#include "type.h"
				#include "board.h"
				#include "codec.h"
				#include "mcbsp54.h"
				
				/* ************************************************************************* */
				/* Function Prototypes */
				/* ************************************************************************* */
				
				/* This delay routine does not conflict with DSP/BIOS.  It is used in this  */
				/* example rather than brd_delay_msec which causes DSP/BIOS conflicts just  */
				/* because of this.  If you are not using DSP/BIOS, you can change the code */
				/* to use brd_delay_msec.                                                   */
				
				void delay(s16 period);
				
				
				/*****************************************************************************/
				/* Global Variables                                                          */
				/*****************************************************************************/
				
				HANDLE hHandset;
				s16 data;
				
				
				/*****************************************************************************/
				/* MAIN */
				/*************************************************************************** */
				
				void main()
				{
				    s16 cnt=2;
				
				    if (brd_init(100))
				        return;
				
					/* blink the leds a couple times */
					while ( cnt-- )
					{
						brd_led_toggle(BRD_LED0);
						/* brd_delay_msec(1000); */
						delay(1000);
						brd_led_toggle(BRD_LED1);
						/* brd_delay_msec(1000); */
						delay(1000);
						brd_led_toggle(BRD_LED2);
						/* brd_delay_msec(1000); */
						delay(1000);
					}
				
				
				    /* Open Handset Codec */
				    hHandset = codec_open(HANDSET_CODEC);               /* Acquire handle to codec */
				
				    /* Set codec parameters */
				    codec_dac_mode(hHandset, CODEC_DAC_15BIT);          /* DAC in 15-bit mode */
				    codec_adc_mode(hHandset, CODEC_ADC_15BIT);          /* ADC in 15-bit mode */
				    codec_ain_gain(hHandset, CODEC_AIN_6dB);            /* 6dB gain on analog input to ADC */
				    //codec_aout_gain(hHandset, CODEC_AOUT_MINUS_6dB);    /* -6dB gain on analog output from DAC */
				    codec_sample_rate(hHandset,SR_16000);               /* 16KHz sampling rate */
				
				
				    /* Polling and digital loopback */
				    while (1)
				    {
				       /* Wait for sample from handset */
				       while (!MCBSP_RRDY(HANDSET_CODEC)) {};
				
				       /* Read sample from and write back to handset codec */
				       data = *(volatile u16*)DRR1_ADDR(HANDSET_CODEC);
				       *(volatile u16*)DXR1_ADDR(HANDSET_CODEC) =2*data;
				    }
				
				//return;
				}
				
				
				void delay(s16 period)
				{
				    int i, j;
				    
				    for(i=0; i				    {
				        for(j=0; j>1; j++);
				    }
				}