1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
|
/**********************************************************************
*
* HDFF firmware command interface library
*
* Copyright (C) 2011 Andreas Regel
*
* 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; if not, write to the
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
*********************************************************************/
#include <string.h>
#include "bitbuffer.h"
void BitBuffer_Init(BitBuffer_t * BitBuffer,
uint8_t * Data, uint32_t MaxLength)
{
memset(Data, 0, MaxLength);
BitBuffer->Data = Data;
BitBuffer->MaxLength = MaxLength * 8;
BitBuffer->BitPos = 0;
}
void BitBuffer_SetBits(BitBuffer_t * BitBuffer, int NumBits, uint32_t Data)
{
uint32_t nextBitPos;
uint32_t bytePos;
uint32_t bitsInByte;
int shift;
if (NumBits <= 0 || NumBits > 32)
return;
nextBitPos = BitBuffer->BitPos + NumBits;
if (nextBitPos > BitBuffer->MaxLength)
return;
bytePos = BitBuffer->BitPos / 8;
bitsInByte = BitBuffer->BitPos % 8;
BitBuffer->Data[bytePos] &= (uint8_t) (0xFF << (8 - bitsInByte));
shift = NumBits - (8 - bitsInByte);
if (shift > 0)
BitBuffer->Data[bytePos] |= (uint8_t) (Data >> shift);
else
BitBuffer->Data[bytePos] |= (uint8_t) (Data << (-shift));
NumBits -= 8 - bitsInByte;
bytePos++;
while (NumBits > 0)
{
shift = NumBits - 8;
if (shift > 0)
BitBuffer->Data[bytePos] = (uint8_t) (Data >> shift);
else
BitBuffer->Data[bytePos] = (uint8_t) (Data << (-shift));
NumBits -= 8;
bytePos++;
}
BitBuffer->BitPos = nextBitPos;
}
uint32_t BitBuffer_GetByteLength(BitBuffer_t * BitBuffer)
{
return (BitBuffer->BitPos + 7) / 8;
}
|
