halcrc.c

一个免费的SMART CARD OS系统。

/* ============================================================================
   Project Name : jayaCard
   Module Name  : proto/hal/simu/halcrc.c
   Version : $Id: halcrc.c,v 1.7 2004/01/11 09:56:33 dgil Exp $

	Description: CRC calculus

    The Original Code is jayaCard code.

    The Initial Developer of the Original Code is Gilles Dumortier.

    Portions created by the Initial Developer are Copyright (C) 2002-2004 the
    Initial Developer. All Rights Reserved.

    Contributor(s):

    This program is free software; you can redistribute it and/or modify
    it 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.

    You should have received a copy of the GNU General Public License
    along with this program; see http://www.gnu.org/licenses/gpl.html

   History Rev	Description
   011903 dgil	wrote it from scratch
   ============================================================================
*/

#include "precomp.h"

/* =========================================================================
	Local
   ========================================================================= */

jword	__simu_crc;

/* =========================================================================
	__hal_tcl_init_crc()

	initialise the T=CL CRC to begin a calculation.

	use tcl_type { TCL_TYPEA; TCL_TYPEB } to initialise the correct CRC.

   ========================================================================= */

void __hal_tcl_init_crc(void)
{
	if (tcl_type==TCL_TYPEA) {
		__simu_crc = 0x6363;
	} else {
		__simu_crc = 0xFFFF;
	}
	/* LOG2("HAL_CRC", "Init with %.4X (%s)", __simu_crc, tcl_type == TCL_TYPEA ?
		"Type A" : "Type B" ); */
}

/* =========================================================================
	__hal_crc_init()

	initialise the system CRC to begin a calculation.
   ========================================================================= */

void __hal_crc_init(void)
{
	__simu_crc = 0x6363;
}

/* =========================================================================
	__simu_calculate_crc()
   ========================================================================= */

void __simu_calculate_crc(jbyte by)
{
	/* LOG1("HAL_CRC", "Calculate CRC on byte %.2x", by ); */
	by = (by^(jbyte)(__simu_crc & 0x00FF));
	by = (by^(by<<4));
	__simu_crc = (__simu_crc >> 8)^((jword)by << 8)^((jword)by<<3)^((jword)by>>4);
	/* LOG1("HAL_CRC", "New CRC value %.4x", __simu_crc ); */
}

/* =========================================================================
	__simu_tcl_locrc()
   ========================================================================= */

jbyte __simu_tcl_locrc(void)
{
	if (tcl_type==TCL_TYPEA) {
		return LOBYTE(__simu_crc);
	} else {
		return LOBYTE(~__simu_crc);
	}
}

/* =========================================================================
	__simu_tcl_hicrc()
   ========================================================================= */

jbyte __simu_tcl_hicrc(void)
{
	if (tcl_type==TCL_TYPEA) {
		return HIBYTE(__simu_crc);
	} else {
		return HIBYTE(~__simu_crc);
	}
}

/* =========================================================================
	__simu_crc_lo()
   ========================================================================= */

jbyte __simu_crc_lo(void)
{
	return LOBYTE(__simu_crc);
}

/* =========================================================================
	__simu_crc_hi()
   ========================================================================= */

jbyte __simu_crc_hi(void)
{
	return HIBYTE(__simu_crc);
}

/* =========================================================================
	That's all folks !
   ========================================================================= */