// initialize the a2d
	readCh(0xFC);

	// start the second time
	TR0 = 1;
	ET0 = 1;		// enable timer 0 int

	EA = 1;
	CS=1;
	CLK = 0;

	// show we're alive
	send_string("TLV2556 V1.0 07/19/11",1);
	
	// Begin program loop  	
 	while(1) 
		{
		if( clock_flag ) {
			clock_flag = 0;
			getChan();
			}

		// if something received in serial port
		if( cmd_complete ) processCommand();
		}
	}

void getChan()
	{
	readCh(0x50);
	sprintf(st,"chan 5 = %3.3f",dBits * MV_PER_BIT);
	send_string(st,1);
	}

// *************************************************
// T L V 2 5 5 6   R E L A T E D   F U N C T I O N S
// *************************************************

void myWait(uchar cnt)
	{
	uchar i;

	for(i=0;i<cnt;cnt++) _nop_();
	}	

void readCh( uchar cmd )
	{
	uchar c2,i;

	CS = 0;						// clear CS and CLK
	CLK = 0;
	dBits = 0;					// start with zero

	myWait(50);					// wait for CS to settle

	for( i=1;i<13;i++)
		{
		if( i < 9)				// 1st 8 clks shift in new control byte
			{
			c2 = _crol_(cmd,i);	// rotate left to access MSB
			c2 &= 0x01;			// mask all but LSB
			if( c2 == 0x01 ) D_IN = 1;
			if( c2 == 0x00 ) D_IN = 0;
			}
			else 
				D_IN = 1;		// keeping hi reduces noise to a2d

		CLK = 1;				// set CLK to shift in bits
		myWait(10);

		// now read the new a2d data
		if( D_OUT == 1 ) dBits |= 0x0001;
			else if( D_OUT == 0) dBits |= 0x0000;

		CLK = 0;
		//myWait(15);
		if( i < 12 ) dBits <<= 1;		// slide bit to left to prepare for next bit
		}

	CS = 1;
	while( EOC == 0 );
	//myWait(30);
	}