/* 
 **********************************************************************
 * File  demo_ppi.C    -    Rel. 1.1  compile with  uC/51 V. 1.10.10  *
 * GRIFO(R)   via Dell'Artigiano 8/6   40016 S. Giorgio di Piano (BO) *
 * Cards: GPC 554 d.s. 100997 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                                   26.09.03   *
 **********************************************************************

 Rel. 1.1 - 26.09.2003 by Graziano Gaiba

 Connect CN5 of GPC(r) 554 to CN15 of DEB01 or CN1 of TIO16 through a
 20 pins+26 pins flat.

 This program allows to manage 16 TTL digital lines.
*/

#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



// On board peripherals registers allocation addresses.
near   unsigned char	    P4	    @ 0xC0;


	
/********* 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--)
    ;
}


// Set port A
void setPortA(unsigned char v)
{
  P4=v;
}


// Set port C
void setPortC(unsigned char v)
{
  P1=v;
}


// Get port A
unsigned char getPortA(void)
{
  return P4;
}


// Get port C
unsigned char getPortC(void)
{
  return P1;
}


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

  do
  {
    for (r=0 ; r<380 ; r++);
    rit--;
  }
  while (rit>0);
}


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

void main(void)
{
  unsigned char c;

  setup();                         // Wait for signals settling

  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
  setPortC(0xff);	        	// PORT C in OUTPUT

  puts("*************************** Demo PPI  ***************************");
  puts("");
  puts("This demo drives the shift activation of the lines of Port A and shows");
  puts("continuously the value of Port C, available on CN5.\n");

  for (;;)		           // Loop forever.
  {
    // Shift from red LEDs to yellow and green LEDs
    c=1;
    while(c)
    {
      setPortA(~c);
      c<<=1;
      // Delay to make the movement of the LED visible
      ritardo(1000);
      printf("%X\r", getPortC());
    }

    c=0x80;
    while(c)
    {
      setPortA(~c);
      c>>=1;
      // Delay to make the movement of the LED visible
      ritardo(1000);
      printf("%X\r", getPortC());
    }
  }			  			  	 
}