rddsp.c

单片机C源程序souce

#include <SST89V564.H>
#include <ABSACC.H>

extern wdt(void);
extern unsigned char xdata sdata[255];
extern unsigned char xdata TXLen;
extern bit TX;

extern rdDSP(void)
{
unsigned char rbuf,counter;
bit ER;
unsigned int j;
		//"i" is the counter for Cyc.
		//"rbuf" is the receiveing buffer for receiveing data from DSP.
wdt();
counter = 0;
ER = 0;
TX = 0;
			//write the HPIA(the read address)
XBYTE[0xe4ff]=0x79;//the higher 8bit of the address.
					//HR/W=0;HCNT1=1;HCNT0=0;HBIL=0.	
XBYTE[0xe5ff]=0x80;//The lower 8bit of the address.
					//HR/W=0;HCNT1=1;HCNT0=0;HBIL=1.
rbuf = 0xff;
while(rbuf!=0x00)
	{
	j=XBYTE[0xeaff];//HR/W=1;HCNT1=0;HCNT0=1;HBIL=0.The higher 8-bit.
	rbuf=XBYTE[0xebff];//HR/W=1;HCNT1=0;HCNT0=1;HBIL=1.The lower 8-bit.
	sdata[counter++]=rbuf;	//Send data.
	if (counter >= 255){ER = 1;break;}
	}
XBYTE[0xe0ff]=0x08;	//HPIC=0x08.
					//HR/W=0;HCNT1=0;HCNT0=0;HBIL=0.
XBYTE[0xe1ff]=0x08;	//HR/W=0;HCNT1=0;HCNT0=0;HBIL=1.
if (ER == 0)
	{
	TXLen = counter-1;
	TX = 1;
	}
}