_idereadsector.c

来自「用C51单片机实现的MP3播放器的c代码程序。」· C语言 代码 · 共 30 行

#ifndef _IDEIO_DEFINE
 #include "IDEIO.c"
#endif

BYTE _IDEReadSector(void);

BYTE _IDEReadSector(void)
{
	register BYTE *sector;
	register WORD i;

	sector=(BYTE *)&IDE.CurrentSector;

	if (!IDEStatus(IDE_STATUS_BSY,IDE_WAIT,FALSE,255))  return(IDE_ERROR_BSY);
	if (!IDEStatus(IDE_STATUS_DRDY,IDE_WAIT,TRUE,255)) return(IDE_ERROR_DRDY);
	IDE_WRITE_LSB(IDE_ADDR_CMD_LBA0,sector[3]);
	IDE_WRITE_LSB(IDE_ADDR_CMD_LBA1,sector[2]);
	IDE_WRITE_LSB(IDE_ADDR_CMD_LBA2,sector[1]);
	IDE_WRITE_LSB(IDE_ADDR_CMD_LBA3,0xe0|IDE.CurrentDevice|(sector[0]&0x0f));
	IDE_WRITE_LSB(IDE_ADDR_CMD_SECCNT,0x01);
	IDE_WRITE_LSB(IDE_ADDR_CMD_COMMAND,IDE_CMD_READ);
	if (!IDEStatus(IDE_STATUS_BSY,IDE_WAIT,FALSE,255))  return(IDE_ERROR_BSY);
	if (!IDEStatus(IDE_STATUS_DRQ,IDE_WAIT,TRUE,255)) return(IDE_ERROR_DRQ);
	for(i=0;i<512;)
	{
		IDE_READ_WORD(IDE_ADDR_CMD_DATA,DiskBuffer[i++],DiskBuffer[i++]);
	}
	return(0);
}