11**************************  FIGURE  12  ********************************
 Ii**		**
 I/**	SERIAL  PROGRA~gfING ROUTINE  FOR THE  PIC16C84  MICROCONTROLLER	**
 II**		**
 //**	Analog Design Specialists	**
 11**		**
 11*********************************************************************

 //FUNCTION PROTOTYPE: int ser_picl6c84(int cmd, int data)

 /l cmd: LOAD_CONFIG		-> part configuration bits
 I/	LOAD_DATA	-> program data, write
 //	READ_DATA	-> program data, read
 //	INC_ADDR	-> increment to the next address (routine does not auto increment)
 //	BEGIN_PROG	-> program a previously loaded program code or data
 //'	LOAD_DATA_DM	-> load EEPROM data regesters  (BEGIN_PROG must folow)
 //	READ_DATA_DM  -> read EEPROM data
 /l
 //data: 1) 14 bits of program data or
 //         2)   8 bits of EEPROM data (least significant 8 bits of int)

II Additional progray,net commands (not part of PICI6C84 programming codes)
//
//~=~d: RESET		-> provides 1 ms reset pulse to target system
//	PROGRAM_MODE	-> initializes PIC16C84 for programming
//	RUN	-> disconnects programmer from target system
//
//function returns:l) 14 or 8 bits read back data for read commands
//		2)  zero	for write data
//		3) PIC_PROG_EROR = -1 for programming function errors
//		4) PROGMR_ERROR  = -2 for programmer function errors

iinclude <bios. h>

#define LOAD_CONFIG	0
idefine LOAD_DATA	2
#define READ_DATA	4
~define INC_ADDR	6
#define BEGIN_PROG	8
#define PARALLEL_MODE 10		//not used
#define LOAD_DATA_DM	3
#define READ_DATA_DM	5
#define MAX_PIC_CMD	63	//division between pic and programmer commands

#define RESET	64	//external reset command, not neded for prograr~ning
#define PROGRAM_MODE	65	//initialize program mode
#define RUN	66	//electrically disconnect programmer

#define PIC_PROG_EROR -1
#define PROGMR_ERROR  -2

#define PTR                0   //use device

//parallel port bits
//	dO: data output to part to be programmed
//	dl: programming clock
//	d2: data dirrection, O= enabel t~i state bur -> send data to part
//	d3: Vpp control 1= turn on Vpp
//	d4: ~MCLR =0,  1 = reset device with MCLR line
//	d5: clock line tri state control, 0 = enable clock line

int ser_picl6c84(int c=nd, int data)	//custom interface for pic 16c84
{
int i, s_cmd;

if(cmd <=MAX_PIC_CMD)	//all programming modes
{
biosprint(O,8,pTH);	//set bits 001000, output mode, clock & data low
OSOO589A-page 4			(C) 1994 Microchip Technology Inc.


   PC-Based Development Programmer for the PIC16C84    I

	s_cmd = cmd;		//retain command 'cmd'
	for (i=O;i<6;i++)		//output 6 bits of co__and
	{
	biosprint(O, (s_cmdaOxl) +2+8,PTR);		//set bits 001010, clock hi
	biosprint(O, (s_cmd&Oxl)	+8,PTR);	//set bits 001000, clock low
	s_cmd >>=1;
	}

	if( (cmd ==INC_ADDR) 11 (cmd ==PA/~ALLEL_MODE)	//com~and only, no data cycle
	return O;

	else if(cmd ==BEGIN_PROG)	//program co__and only, no data cycle
	{
	delay(i0);	//10 ms PIC programming time
	return O;
	}

	else if( (cmd ==LOAD_DATA)I1 (cmd ==LOAD_DATA_DM)1~ (cmd ==LOAD_CONFIG))//output 14 bits of		I
data
	for (i=200;i;i--)  ;	//delay between command & data
	biosprint(O,2+8,PTR);	//set bits 001010, clock hi; leading bit
	biosprint(O,   8,PTR);	/ set bits 001000, clock low

	for (i=O;i<14;i++)		/ 14 data bits,  isb first
	{
	biosprint(O,(data&Oxl)  +2+8,PTR);		/ set bits 001010,	clock hi
	biosprint(O,(dataaOxl)	+8,PTR);	/ set bits 001000,	clock low
	data >>=1;
	}
	biosprint(O,2+8,PTR);		//set bits 001010, clock hi; trailing bit

 // *****************    Analog Design  Specialists    ******************

   biosprint(O,   8,PTR);                                  //set bits 001000,  clock low

   return 0;
   }

 else if((c=nd ==READ_DATA)II(omd ==READ_DATA_DM))//read 14 bits from part,  isb first
  {
	biosprint(O,   4+8,PTR);	//set bits 001100, clock low,  tri state data
			buffer
	for (i=200;i;i-)  ;	//delay between co~and a data
	biosprint(O,2+4+8,PTR);	//set bits 001110, clock hi,  leading bit
	biosprint(O,   4+8,PTR);	//set bi~s 001100, clock low

   data =0;
   for (i=O;i<14;i++)		//input 14 bits of data,  Isb first
   {
   data >>=1;		//shift data for next input bit
   biosprint(O,2+4+8,PTR);		//set bits 001110,   clock hi
   biosprint(O,   4+8,PTR);		//set bits 001100,   clock low
    if(!(biosprint{2,0,O)aOx40))  data += Ox2000;  //use printer acknowledge line for input,
                                    data Isb first
    }
   biosprint(O,2+4+8,PTR);		//set bits 001110, clock hi, trailing bit
   biosprint(O,	4+8,PTR);	//set bits 001100, clock low
   return data;
   }

 else return PIC_PROG_EROR;                            //programmer error

}
else if(omd == RESET)	//reset device
biosprint(O,32+l6+4,PTR);	//set bits 110100, MCLR = low (rese~
		PIC16C84), progranTaer not conected

1994 Microchip Technology Inc.                                                                 DSOO589A-page 5


A PC-Based Development Programmer for the PIC16C84  ~i

  delay(l);		//Ims delay
  biosprint(O,32	+4,PTR);	//set bits 100100, MCLR = high
  return O;

	else if(cmd ==PROGRAM_MODE)	//enter program mode
	biosprint(O,32+l6+4,PTR);	//set bits 110100, Vpp off, MCLR = low
				(reset PIC16C84)
	delay(i0);	//10 ms, allow programming voltage to
				stabelize

  biosprint(O,8,PTR);	//set bits 001000, Vpp on , MCLR = 13.5
			volts, clock & data connected
  delay(i0);	//10 ms, allow progra~mning voltage to
			stablize

  return O;
  }

else if(cmd ==RUN)	//disconects prograr~ner from device
biosprint(O,32+4,PTR);	//set bits 100100
return 0;
}
else return PROGMR_ERROR;	//command error