/* 
 **********************************************************************
 * File  demo_ppi.C     -     Rel. 1.1  compile with  uC/51 V. 1.10.7 *
 * GRIFO(R)   via Dell'Artigiano 8/6   40016 S. Giorgio di Piano (BO) *
 * Cards: GPC 552 d.s. 180796 and DEB01 or TIO16                      *
 *     Tel. +39 051 892052                      Fax. +39 051 893661   *
 *     http://www.grifo.com                     http://www.grifo.it   *
 *     sales@grifo.it         tech@grifo.it          grifo@grifo.it   *
 *     by Graziano Gaiba                               del 10.09.03   *
 **********************************************************************

 Rel. 1.1 - 10.09.2003 by Graziano Gaiba

 Connect CN15 of DEB01 or CN1 of TIO16 through a 20 pins flat to CN2 
 (for output) or CN1 (for input) of GPC(r) 552.

 This program allows to manage all the 24 TTL digital lines of PPI
 82c55, at the same time a sound indicates output setting.
*/

#include <reg52.h>
#include <stdio.h>
#include <ctype.h>

// Clock frequency of CPU used
#define FCLOCK              22118400

#define FALSE 0x00					   // Boolean values
#define TRUE 0xFF

near unsigned char	    CKCON   @ 0x8E;		    // SFR of DALLAS

// On board peripherals registers allocation addresses.
static unsigned char  	    PORTA   @ 0xFFF8,
			    PORTB   @ 0xFFF9,
			    PORTC   @ 0xFFFA,
			    CNT     @ 0xFFFB,
                            DSW1    @ 0xFFFD;
static unsigned char        BUZ     @ 0xFFFC;

// Variables used by the program
near unsigned char	dallas;


	
/********* General purpose utilities and hw sections management ***********/
void iniser(unsigned long baud)
/* Initialise serial port with:		Bit x chr   = 8
					Stop bit    = 1
					Parity	    = None
					Baud rate   = baud
   using timer 1 as baud rate generator.				   */
{
  SCON=0x052;					  // Modo 1, receiver enabled
  TMOD&=0x00F;				       // Timer 1 in auto-reload mode
  TMOD|=0x020;
  TR1=0;						      // Stop TIMER 1
  TH1=256-((2*FCLOCK)/(384*baud));		       // baud at 14.7456 MHz
  PCON=PCON|0x080;			   // Set SMOD=1 for higher baud rate
  TR1=1;						     // Start TIMER 1
}


// Wait for signals settling
void setup(void)
{
  unsigned int i;

  for(i=10000; i!=0; i--)
    ;
}


// Initialise 82c55 with value in parameter
void init8255(unsigned char c)
{
  CNT=c;
}


// Set port A of 82c55
void setPortA(unsigned char v)
{
  PORTA=v;
}


// Set port B of 82c55
void setPortB(unsigned char v)
{
  PORTB=v;
}


// Set port C of 82c55
void setPortC(unsigned char v)
{
  PORTC=v;
}


// Get port A of 82c55
unsigned char getPortA(void)
{
  return PORTA;
}


// Get port B of 82c55
unsigned char getPortB(void)
{
  return PORTB;
}


// Get port C of 82c55
unsigned char getPortC(void)
{
  return PORTC;
}


// Get value of DSW1
unsigned char getDSW1(void)
{
  return DSW1;
}


void init_cpu(void)
/* Checks which CPU is installed on the card and stores the information.   */
{
  unsigned char dr;

  dr=CKCON;				  // Legge registro del DALLAS 80C320
  if (CKCON==0x01)
  {
    CKCON=0x01;			// Setta accesso area dati a 3 cicli macchina
    dallas=TRUE;				       // E` un DALLAS 80C320
  }
  else
    dallas=FALSE;					       // E` un 80C32
//endif
}


void ritardo(unsigned int rit)
/* Software delay of rit milliseconds, calibrated for 22.1184 MHz,
   according to the CPU installed.                                   */
{
unsigned int r,rit1ms;

  if (dallas==TRUE)
    rit1ms=380;	     // 1 msec. for 80c320
   else 
    rit1ms=150;	      // 1 msec. for 80c32
  do
  {
    for (r=0 ; r<rit1ms ; r++);
    rit--;
  }
  while (rit>0);
}


// Makes a short noise by on-board buzzer
void bip(void)
{
    BUZ |= 0x04;	// Turn on buzzer.
    ritardo(300);
    BUZ &= ~0x04;	// Turn off buzzer.
}


// Makes a short noise and performs about three seconds of total delay
void ritardo_bip(void)
{
  bip();
  ritardo(700);
}



// **************************** Main program *****************************

void main(void)
{
  unsigned char c;

  setup();                         // Wait for signals settling
  init_cpu();                      // Check CPU installed

  iniser(19200);
  TI=0;
  RI=0;

  // Comment next two lines if serial port is used in polling (SIOTYPE=p or k)
  ES=1;                                 // Enable serial port interrupt
  EA=1;					// Enable all interrupts

// Initialisation of PPI 8255.
  init8255(0x82);	        // PORT A and C in OUTPUT, PORT B in INPUT.

  puts("*************************** Demo PPI  ***************************");
  puts("");
  puts("This demo drives the shift activation of the lines of Port A and C available on");
  puts("connector CN2 and shows continuously the value of Port B, available on CN1.\n");

  for (;;)		           // Loop forever.
  {
    // Shift from red LEDs to yellow and green LEDs
    c=1;
    setPortC(0xff);                // Clears Port C
    while(c)
    {
      setPortA(~c);
      c<<=1;
      // Delay to make the movement of the LED visible
      ritardo_bip();
      printf("%X\r", getPortB());
    }
    c=1;
    setPortA(0xff);                // Clears Port A
    while(c)
    {
      setPortC(~c);
      c<<=1;
      // Delay to make the movement of the LED visible
      ritardo_bip();
      printf("%X\r", getPortB());
    }


    // Shift from yellow and green LEDs to red LEDs
    c=0x80;
    setPortA(0xff);                // Clears Port A
    while(c)
    {
      setPortC(~c);
      c>>=1;
      // Delay to make the movement of the LED visible
      ritardo_bip();
      printf("%X\r", getPortB());
    }
    c=0x80;
    setPortC(0xff);                // Clears Port A
    while(c)
    {
      setPortA(~c);
      c>>=1;
      // Delay to make the movement of the LED visible
      ritardo_bip();
      printf("%X\r", getPortB());
    }
  }			  			  	 
}