i2s_test.c

IARSOURCECODE是基于LPC2478嵌入式软件IAR EWARM V4.42的应用实例代码

/*****************************************************************************
 *   i2stest.c:  main C entry file for NXP LPC23xx/24xx Family Microprocessors
 *
 *   Copyright(C) 2006, NXP Semiconductor
 *   All rights reserved.
 *
 *   History
 *   2006.07.20  ver 1.00    Prelimnary version, first Release
 *
******************************************************************************/
#include "LPC2468.h"                        /* LPC23xx/24xx definitions */
#include "type.h"
#include "irq.h"
#include "i2s.h"
#include "dma.h"

extern volatile BYTE *I2STXBuffer, *I2SRXBuffer;
extern volatile DWORD I2SReadLength;
extern volatile DWORD I2SWriteLength;
extern volatile DWORD I2SRXDone, I2STXDone;
extern volatile DWORD I2SDMA0Done, I2SDMA1Done;

/*******************************************************************************
**   Main Function  main()
*******************************************************************************/
int main (void)
{
  DWORD i;

  /* The test program is to connect CLK, WS, and SDA lines between the
  TX and RX. DAO is the master output, DAI is the slave input. This test
  is not a real-world application but test both TX and RX channel in
  a single program. However, due to the sync issue, the TX will start with
  MUTE data 0 once it starts while RX is not ready. So, it may begins
  with some MUTE value in the beginning of the RX buffer. This is beyond
  control unless throw away the very first few bytes in the RX buffer.
  In this program, the very first byte is not compared between the TX buffer
  and RX buffer due to this synchonization issue. */

  /* Configure temp register before reading */
  for ( i = 0; i < BUFSIZE; i++ )	/* clear buffer */
  {
	I2STXBuffer[i] = i;
	I2SRXBuffer[i] = 0;
  }

  if ( I2SInit() == FALSE )	/* initialize I2S */
  {
	while ( 1 );			/* Fatal error */
  }

#if I2S_DMA_ENABLED
  /* USB RAM is used for test.
  Please note, Ethernet has its own SRAM, but GPDMA can't access
  that. GPDMA can access USB SRAM and IRAM. Ethernet DMA controller can
  access both IRAM and Ethernet SRAM. */
  PCONP |= (1 << 29);	/* Enable GPDMA clock */

  GPDMA_INT_TCCLR = 0x03;
  GPDMA_INT_ERR_CLR = 0x03;

  GPDMA_CONFIG = 0x01;	/* Enable DMA channels, little endian */
  while ( !(GPDMA_CONFIG & 0x01) );

  /* on DMA channel 0, Source is memory, destination is I2S TX FIFO,
  on DMA channel 1, source is I2S RX FIFO, Destination is memory */
  /* Enable channel and IE bit */
  DMA_Init( 0, M2P );
  GPDMA_CH0_CFG |= 0x18001 | (0x00 << 1) | (0x05 << 6) | (0x01 << 11);
  DMA_Init( 1, P2M );
  GPDMA_CH1_CFG |= 0x08001 | (0x06 << 1) | (0x00 << 6) | (0x02 << 11);

  if ( install_irq( GPDMA_INT, (void *)DMAHandler, HIGHEST_PRIORITY ) == FALSE )
  {
	while ( 1 );	/* Fatal error */
  }
  I2SStart();

  I2S_DMA2 = (0x01<<0) | (0x08<<8);	/* Channel 2 is for RX, enable RX first. */
  I2S_DMA1 = (0x01<<1) | (0x01<<16);/* Channel 1 is for TX. */

  /* Wait for both DMA0 and DMA1 to finish before verifying. */
  while ( !I2SDMA0Done || !I2SDMA1Done );
#else
  /* Not DMA mode, enable I2S interrupts. */
  /* RX FIFO depth is 1, TX FIFO depth is 8. */
  I2SStart();
  I2S_IRQ = (8 << 16) | (1 << 8) | (0x01 << 0);

  while ( I2SWriteLength < BUFSIZE )
  {
	while (((I2S_STATE >> 16) & 0xFF) == TXFIFO_FULL);
	I2S_TX_FIFO = I2STXBuffer[I2SWriteLength++];
  }

  I2STXDone = 1;
  /* Wait for RX and TX complete before comparison */
  while ( !I2SRXDone || !I2STXDone );
#endif

  /* Validate TX and RX buffer */
  for ( i=1; i<BUFSIZE; i++ )
  {
	if ( I2SRXBuffer[i] != I2STXBuffer[i-1] )
	{
	  while ( 1 );	/* Validation error */
	}
  }
  return 0;
}

/******************************************************************************
**                            End Of File
******************************************************************************/