47 lines
653 B
C
47 lines
653 B
C
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/*++
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Copyright (c) 1992 Microsoft Corporation
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Module Name:
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crc.c
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Abstract:
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Author:
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Thomas J. Dimitri (TommyD) 08-May-1992
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Environment:
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Kernel Mode - Or whatever is the equivalent on OS/2 and DOS.
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Revision History:
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--*/
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#include "asyncall.h"
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// asyncmac.c will define the global parameters.
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#include "globals.h"
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#include "crctable.h"
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USHORT
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CalcCRC(
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register PUCHAR Frame,
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register UINT FrameSize)
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{
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register USHORT currCRC=0;
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// we use a do while for efficiency purposes in loop optimizations
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do {
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currCRC=crc_table[((currCRC >> 8) ^ *Frame++) & 0xff] ^ (currCRC << 8);
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} while(--FrameSize);
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return currCRC;
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}
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