tiny_sci.c

/*
  SCI 操作
  Satofumi KAMIMURA
  $Id$
*/

#include "tiny_sci.h"
#include "cpu_spec.h"

enum {
  //FirstBaudrate = 9600,
  FirstBaudrate = 115200,
  SCI_BIT_WAIT = (int)(CPU_CLOCK / FirstBaudrate / 7.0),
};


int setBaudrate(long baudrate) {
  switch (baudrate) {

  case 9600:
    SCI1.BRR = 92;
    break;

  case 38400:
    SCI1.BRR = 22;
    break;

  case 57600:
    SCI1.BRR = 15;
    break;

  case 115200:
    SCI1.BRR = 7;
    break;

  default:
    return -1;
  }
  return 0;
}


void initSCI(void) {
  volatile int i;
  
  SCI1.SCR.BYTE = 0x00;
  SCI1.SMR.BYTE = 0;            /* 8bit, 1stop, no parity */
  setBaudrate(FirstBaudrate);
  for (i = 0; i < SCI_BIT_WAIT; ++i) /* wait 1 bit */
    ;
  PFC.PACRL2.WORD |= 0x0140;    /* enable RxD1, TxD1 */
  SCI1.SCR.BYTE = 0x30;         /* TE = 1, RE = 1 */
  SCI1.SSR.BYTE &= ~0x40;
}


char getch(void) {
  char ch;
  
  while((SCI1.SSR.BYTE & 0x40) == 0) /* RDRF */
    ;
  ch = SCI1.RDR;
  SCI1.SSR.BYTE &= ~0x40;       /* clear RDRF */

  return ch;
}


int recvLine(char *buffer, int maxlen) {
  int i;

  for (i = 0; i < maxlen-1; ++i) {
    char ch = getch();
    if ((ch == '\0') || (ch == '\r') || (ch == '\n')) {
      break;
    }
    buffer[i] = ch;
  }
  buffer[i] = '\0';

  return i;
}


void putch(char ch) {
  while ((SCI1.SSR.BYTE & 0x80) == 0) /* TDRE */
    ;
  SCI1.TDR = ch;
  SCI1.SSR.BYTE  &= ~0x80;
}


int putstr(char *data) {
  char *ch = data;

  while (*ch != '\0') {
    putch(*(ch++));
  }
  return (ch - data);
}