/*
SEROUT.C

Interrupt driven serial communication with embOS real time operating system
Sample program that can be used without changes in applications

Needs definitions similar to the following in MAIN.H :

#define INTHANDLERST interrupt [0] void IntHandlerSR(void)
#define _WriteSIO(c) U0TB = c;

Declares the following functions for other modules :

void SEROUT_Write(char c);
void SEROUT_Init(void);
*/

#include "MAIN.H" // include file for all modules, incl. RTOS.H
#include "HWDEF.H" // include for hardware definitions

#ifndef SIZEOF_SO
#define SIZEOF_SO (50)
#endif

MAILBOX MBSO; // Mailbox for transmission

char BufferSO[SIZEOF_SO];
char Sending;

//
// Defines the interrupt routine for serial transmission.
// Basic operation is as follows :
// If there is one character in Buffer it is send
// Otherwise the global variable Sending is cleared
//

INTHANDLERST
{
  char c;
  EnterInterrupt();
  if (!GetMailCond1(&MBSO, &c)) {
    _WriteSIO(c);
  } else
    Sending =0;
  LeaveInterrupt();
}

//
// Writes one character to the SIO
// Basic operation is as follows :
//
// If transmission already in progress, put character in buffer
// Where the interrupt routine will get it
// Otherwise set global variable Sending and write into register
//

void SEROUT_Write(char c) {
  SDI(); // disable interrupts
  if (Sending)
    PutMail1(&MBSO, &c);
  else {
    Sending =1;
    _WriteSIO(c);
  }
  RI(); // restore former status of IE-flag
}

void SEROUT_Init(void) {
  CREATEMB(&MBSO, 1, SIZEOF_SO, &BufferSO);
}