pic14bit.c

MicroChip的12BIt和14Bit的PIC系列单片机的汇编器

/*
 * picasm -- pic14bit.c
 *
 * Timo Rossi <[e-mail]>
 * 
 */

#include <stdio.h>

#include "picasm.h"

/*
 * Assemble 14-bit PIC code
 */
int
assemble_14bit_mnemonic(int op)
{
  long val;
  struct symbol *sym;
  char *cp;
  int t, symtype;

  switch(op) {
    case KW_SUBLW:
    case KW_ANDLW:
    case KW_IORLW:
    case KW_XORLW:
      val = get_expression();
      if(expr_error)
	return FAIL;
      if(val < -0x80 || val > 0xff)
	error(0, "8-bit literal out of range");
      val &= 0xff; /* this assumes 2-complement negative numbers */
      switch(op) {
        case KW_SUBLW: gen_code(0x3c00 | val); break;
	case KW_ANDLW: gen_code(0x3900 | val); break;
	case KW_IORLW: gen_code(0x3800 | val); break;
	case KW_XORLW: gen_code(0x3a00 | val); break;
      }
      break;

    case KW_ADDLW:
      if(gen_byte_c(0x3e00) != OK)
	return FAIL;
      break;

    case KW_MOVLW:
      if(gen_byte_c(0x3000) != OK)
	return FAIL;
      break;

    case KW_ADDWF:
    case KW_SUBWF:
    case KW_ANDWF:
    case KW_IORWF:
    case KW_XORWF:
    case KW_COMF:
    case KW_DECF:
    case KW_INCF:
    case KW_MOVF:
    case KW_DECFSZ:
    case KW_INCFSZ:
    case KW_RLF:
    case KW_RRF:
    case KW_SWAPF:
      val = get_expression();
      if(expr_error)
	return FAIL;
      if(val < 0 || val > 0x7f)
	error(0, "Register file address out of range");
      t = 1;
      if(token_type == TOK_COMMA) {
	get_token();
	t = get_expression();
	if(expr_error)
	  return FAIL;
      }	else {
	if(warnlevel > 0)
	  warning("Destination speficier omitted");
      }

      val = (val & 0x7f) | (t != 0 ? 0x80 : 0);
      switch(op) {
        case KW_ADDWF:  gen_code(0x0700 | val); break;
	case KW_SUBWF:  gen_code(0x0200 | val); break;
	case KW_ANDWF:  gen_code(0x0500 | val); break;
	case KW_IORWF:  gen_code(0x0400 | val); break;
	case KW_XORWF:  gen_code(0x0600 | val); break;
	case KW_COMF:   gen_code(0x0900 | val); break;
	case KW_DECF:   gen_code(0x0300 | val); break;
	case KW_INCF:   gen_code(0x0a00 | val); break;
	case KW_MOVF:   gen_code(0x0800 | val); break;
	case KW_DECFSZ: gen_code(0x0b00 | val); break;
	case KW_INCFSZ: gen_code(0x0f00 | val); break;
	case KW_RLF:    gen_code(0x0d00 | val); break;
	case KW_RRF:    gen_code(0x0c00 | val); break;
	case KW_SWAPF:  gen_code(0x0e00 | val); break;
      }
      break;

    case KW_CLRF:
    case KW_MOVWF:
      val = get_expression();
      if(expr_error)
	return FAIL;
      if(val < 0 || val > 0x7f)
	error(0, "Register file address out of range");
      switch(op) {
        case KW_CLRF:  gen_code(0x0180 | val); break;
	case KW_MOVWF: gen_code(0x0080 | val); break;
      }
      break;

    case KW_BCF:
    case KW_BSF:
    case KW_BTFSC:
    case KW_BTFSS:
      val = get_expression();
      if(expr_error)
	return FAIL;
      if(val < 0 || val > 0x7f)
	error(0, "Register file address out of range");
      if(token_type != TOK_COMMA) {
	error(1, "',' expected");
	return FAIL;
      }
      get_token();
      t = get_expression();
      if(expr_error)
	return FAIL;
      if(t < 0 || t > 7) {
	error(0, "Bit number out of range");
      }
      val |= (t << 7);
      switch(op) {
        case KW_BCF:   gen_code(0x1000 | val); break;
	case KW_BSF:   gen_code(0x1400 | val); break;
	case KW_BTFSC: gen_code(0x1800 | val); break;
	case KW_BTFSS: gen_code(0x1c00 | val); break;
      }
      break;

    case KW_CALL:
    case KW_GOTO:
      t = 0;
      if(token_type == TOK_IDENTIFIER || token_type == TOK_LOCAL_ID) {
	symtype =
	  (token_type == TOK_IDENTIFIER ? SYMTAB_GLOBAL : SYMTAB_LOCAL);

	if(symtype == SYMTAB_LOCAL && local_level == 0) {
	  error(1, "Local symbol outside a LOCAL block");
	  return FAIL;
	}

	sym = lookup_symbol(token_string, symtype);
	if(sym == NULL || sym->type == SYM_FORWARD) {
	  if(sym == NULL) {
	    sym = add_symbol(token_string, symtype);
	    sym->type = SYM_FORWARD;
	  }

	  val = 0;
	  add_patch(symtype, sym, PATCH11);
	  t = 1;
	  get_token();
	  goto gen_goto_call;
	}
      }

      val = get_expression();
      if(expr_error)
	return FAIL;
      if(val < 0 || val >= prog_mem_size)
	error(0, "GOTO/CALL address out of range");
gen_goto_call:
      val &= 0x7ff;
      switch(op) {
        case KW_CALL: gen_code(0x2000 | val); break;
	case KW_GOTO: gen_code(0x2800 | val); break;
      }
      if(t)
	list_flags |= LIST_FORWARD;
	break;

    case KW_TRIS:
      t = get_expression();
      if(expr_error)
	return FAIL;
      if(t < 5 || t > 7)
	error(0, "Invalid register address for TRIS");
      gen_code(0x0060 | t);
      if(warnlevel > 1)
	warning("TRIS instruction not recommended");
      break;

/*
 * RETLW allows multiple parameters/strings, for generating lookup tables
 */
    case KW_RETLW:
      for(;;) {
	if(token_type == TOK_STRCONST) {
	  for(cp = token_string; *cp != '\0'; cp++)
	    gen_code(0x3400 | (int)((unsigned char)(*cp)));
	  get_token();
	} else {
	  if(gen_byte_c(0x3400) != OK)
	    return FAIL;
	}

	if(token_type != TOK_COMMA)
	  break;

	get_token();
      }
      break;

    case KW_NOP:
      gen_code(0x0000);
      break;

    case KW_CLRW:
      gen_code(0x0100);
      break;

    case KW_OPTION:
      gen_code(0x0062);
      if(warnlevel > 1)
	warning("OPTION instruction not recommended");
      break;

    case KW_SLEEP:
      gen_code(0x0063);
      break;

    case KW_CLRWDT:
      gen_code(0x0064);
      break;

    case KW_RETFIE:
      gen_code(0x0009);
      break;

    case KW_RETURN:
      gen_code(0x0008);
      break;

    default:
      error(1, "Syntax error");
      return FAIL;
  }
  return OK;
}