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How to rework "printf" function to use for two UARTS in the cygnal's MCU?

Hi,everyone!
A problem here:The cygnal's MCU has two
serial ports,so "printf" function must be reworked.But I don't know how to do it.
Give me a hand!
Thanks a lot!

Parents

0 Jon Ward over 23 years ago

This is a start on this problem:

//-----------------------------------------------
#include "stdio.h"

volatile unsigned char sio_selector = 0;

//-----------------------------------------------
char putchar (char c)
{
if (sio_selector == 0)
  {
  while (!TI_0);  /* wait until transmitter ready */
  TI_0 = 0;
  SBUF0 = c;      /* output character */
  }
else
  {
  while (!TI_1);  /* wait until transmitter ready */
  TI_1 = 0;
  SBUF1 = c;      /* output character */
  }

return (c);
}


//-----------------------------------------------
char _getkey (void)
{
char c;

if (sio_selector == 0)
  {
  while (!RI_0);  /* wait for a character */
  c = SBUF0;
  RI_0 = 0;       /* clear receive interrupt bit */
  }
else
  {
  while (!RI_1);  /* wait for a character */
  c = SBUF1;
  RI_1 = 0;       /* clear receive interrupt bit */
  }

return (c);
}


//-----------------------------------------------
void main (void)
{
//Initialize SIO0
//Initialize SIO1

while (1)
  {
  sio_selector = 0;
  printf ("Serial Port 0\r\n");

  sio_selector = 1;
  printf ("Serial Port 1\r\n");
  }
}
//-----------------------------------------------

Of course this is polled and uses the putchar and _getkey functions. You'll have to provide your own code to initialize the serial ports and timers.

Jon

Reply

0 Jon Ward over 23 years ago

This is a start on this problem:

//-----------------------------------------------
#include "stdio.h"

volatile unsigned char sio_selector = 0;

//-----------------------------------------------
char putchar (char c)
{
if (sio_selector == 0)
  {
  while (!TI_0);  /* wait until transmitter ready */
  TI_0 = 0;
  SBUF0 = c;      /* output character */
  }
else
  {
  while (!TI_1);  /* wait until transmitter ready */
  TI_1 = 0;
  SBUF1 = c;      /* output character */
  }

return (c);
}


//-----------------------------------------------
char _getkey (void)
{
char c;

if (sio_selector == 0)
  {
  while (!RI_0);  /* wait for a character */
  c = SBUF0;
  RI_0 = 0;       /* clear receive interrupt bit */
  }
else
  {
  while (!RI_1);  /* wait for a character */
  c = SBUF1;
  RI_1 = 0;       /* clear receive interrupt bit */
  }

return (c);
}


//-----------------------------------------------
void main (void)
{
//Initialize SIO0
//Initialize SIO1

while (1)
  {
  sio_selector = 0;
  printf ("Serial Port 0\r\n");

  sio_selector = 1;
  printf ("Serial Port 1\r\n");
  }
}
//-----------------------------------------------

Of course this is polled and uses the putchar and _getkey functions. You'll have to provide your own code to initialize the serial ports and timers.

Jon

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