(*
 * (c) 2003 Mario de Sousa
 *
 * Offered to the public under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
 * Public License for more details.
 *
 * This code is made available on the understanding that it will not be
 * used in safety-critical situations without a full and competent review.
 *)

(*
 * An IEC 61131-3 IL and ST compiler.
 *
 * Based on the
 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10)
 *
 *)

(*
 * This is part of the library conatining the functions
 * and function blocks defined in the standard.
 *
 * Conversion to BCD
 * -----------------
 *)




FUNCTION USINT_TO_BCD_BYTE: BYTE
  VAR_INPUT
    VALUE : USINT;
  END_VAR

  USINT_TO_BCD_BYTE := VALUE MOD 10;
  VALUE := VALUE / 10;
  USINT_TO_BCD_BYTE := USINT_TO_BCD_BYTE + 16*VALUE;
  IF VALUE > 9
  THEN
    (* The standard is silent on how to handle overflows!! *)
    (* We simply set it to the highets value!              *)
    USINT_TO_BCD_BYTE := 16#99;
  END_IF;
END_FUNCTION




FUNCTION UINT_TO_BCD_WORD: WORD
  VAR_INPUT
    VALUE : UINT;
  END_VAR

  UINT_TO_BCD_WORD := VALUE MOD 10;
  VALUE := VALUE / 10;
  UINT_TO_BCD_WORD := UINT_TO_BCD_WORD + 16*(VALUE MOD 10);
  VALUE := VALUE / 10;
  UINT_TO_BCD_WORD := UINT_TO_BCD_WORD + 16*16*(VALUE MOD 10);
  VALUE := VALUE / 10;
  UINT_TO_BCD_WORD := UINT_TO_BCD_WORD + 16*16*16*VALUE;
  IF VALUE > 9
  THEN
    (* The standard is silent on how to handle overflows!! *)
    (* We simply set it to the highets value!              *)
    UINT_TO_BCD_WORD := 16#9999;
  END_IF;
END_FUNCTION




FUNCTION UDINT_TO_BCD_DWORD: DWORD
  VAR_INPUT
    VALUE : UINT;
  END_VAR

  UDINT_TO_BCD_DWORD := VALUE MOD 16;
  VALUE := VALUE / 10;
  UDINT_TO_BCD_DWORD := UDINT_TO_BCD_DWORD + 16*(VALUE MOD 10);
  VALUE := VALUE / 10;
  UDINT_TO_BCD_DWORD := UDINT_TO_BCD_DWORD + 256*(VALUE MOD 10);
  VALUE := VALUE / 10;
  UDINT_TO_BCD_DWORD := UDINT_TO_BCD_DWORD + 16*256*(VALUE MOD 10);
  VALUE := VALUE / 10;
  UDINT_TO_BCD_DWORD := UDINT_TO_BCD_DWORD + 256*256*(VALUE MOD 10);
  VALUE := VALUE / 10;
  UDINT_TO_BCD_DWORD := UDINT_TO_BCD_DWORD + 16*256*256*(VALUE MOD 10);
  VALUE := VALUE / 10;
  UDINT_TO_BCD_DWORD := UDINT_TO_BCD_DWORD + 256*256*256*(VALUE MOD 10);
  VALUE := VALUE / 10;
  UDINT_TO_BCD_DWORD := UDINT_TO_BCD_DWORD + 16*256*256*256*VALUE;
  IF VALUE > 9
  THEN
    (* The standard is silent on how to handle overflows!! *)
    (* We simply set it to the highest value!              *)
    UDINT_TO_BCD_DWORD := 16#9999_9999;
  END_IF;
END_FUNCTION




FUNCTION ULINT_TO_BCD_LWORD: LWORD
  VAR_INPUT
    VALUE : UINT;
  END_VAR

  ULINT_TO_BCD_LWORD := UDINT_TO_BCD_DWORD(VALUE MOD 1_0000_0000);
  VALUE := VALUE / 1_0000_0000;
  ULINT_TO_BCD_LWORD := ULINT_TO_BCD_LWORD + 256*256*256*256*UDINT_TO_BCD_DWORD(VALUE);
END_FUNCTION