/*
 TLC1543//SPI port//11 channels Analog input//10 bit//10us Rate

 2003.1.6
 */
#include <AT89X52.H>
#include <INTRINS.h>

//hardware conection
 #define CLOCK P1_2
 #define D_IN  P1_1
 #define D_OUT P1_3
 #define P_CS   P1_0
 #define EOC   P1_4

typedef 	struct
{	
	unsigned char ah;
	unsigned char al;
}word;


union bitseg
{
	word byte;			
	unsigned int i;
};
 //----------------------------------------
 //data read from (port)channel of tlc1543
 unsigned int tlc1543(unsigned char port){
 unsigned char idata i;
 union bitseg idata c;
 c.byte.al=0,c.byte.ah=0;
 CLOCK=0;
 P_CS=0;//low level start a/d 
 port<<=4;//move to high 4bit
 for(i=0;i<4;i++){//input channels signal
   D_IN=(bit)(port&0x80);CLOCK=1;CLOCK=0;
   port<<=1;
   }
 for(i=0;i<6;i++){//fill 6 clock signal
   CLOCK=1;CLOCK=0;
   }
 P_CS=1;
 _nop_(); _nop_(); _nop_(); _nop_();
 P_CS=0;//wait a/d conversion,EOC low is busy 
 for(i=0;i<2;i++){//get D9,D8 bit
   D_OUT=1;
   CLOCK=1;
   c.byte.ah<<=1;
   if(D_OUT)c.byte.ah|=0x01;
   CLOCK=0;
   }
 for(i=0;i<8;i++){//get D7~D0 bit
   D_OUT=1;
   CLOCK=1;
   c.byte.al<<=1;
   if(D_OUT)c.byte.al|=0x01;
   CLOCK=0;
   }
 P_CS=1;
 _nop_();
 P1=0xff;
 return c.i;
 }