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crc_001.c
Go to the documentation of this file.
1 /*
2 * @brief Cyclic Redundancy Check (CRC) Engine driver
3 *
4 * @note
5 * Copyright(C) NXP Semiconductors, 2012
6 * All rights reserved.
7 *
8 * @par
9 * Software that is described herein is for illustrative purposes only
10 * which provides customers with programming information regarding the
11 * LPC products. This software is supplied "AS IS" without any warranties of
12 * any kind, and NXP Semiconductors and its licenser disclaim any and
13 * all warranties, express or implied, including all implied warranties of
14 * merchantability, fitness for a particular purpose and non-infringement of
15 * intellectual property rights. NXP Semiconductors assumes no responsibility
16 * or liability for the use of the software, conveys no license or rights under any
17 * patent, copyright, mask work right, or any other intellectual property rights in
18 * or to any products. NXP Semiconductors reserves the right to make changes
19 * in the software without notification. NXP Semiconductors also makes no
20 * representation or warranty that such application will be suitable for the
21 * specified use without further testing or modification.
22 *
23 * @par
24 * Permission to use, copy, modify, and distribute this software and its
25 * documentation is hereby granted, under NXP Semiconductors' and its
26 * licensor's relevant copyrights in the software, without fee, provided that it
27 * is used in conjunction with NXP Semiconductors microcontrollers. This
28 * copyright, permission, and disclaimer notice must appear in all copies of
29 * this code.
30 */
31
32 #include "crc_001.h"
33
34 /*****************************************************************************
35 * Private types/enumerations/variables
36 ****************************************************************************/
37
38 /*****************************************************************************
39 * Public types/enumerations/variables
40 ****************************************************************************/
41
42 /*****************************************************************************
43 * Private functions
44 ****************************************************************************/
45
46 /*****************************************************************************
47 * Public functions
48 ****************************************************************************/
49
50 /* Sets up the CRC engine with defaults based on the polynomial to be used */
51 void IP_CRC_UseDefaultConfig(IP_CRC_001_T *pCRC, IP_CRC_001_POLY_T poly)
52 {
53 switch (poly) {
54 case CRC_POLY_CRC16:
55 pCRC->MODE = MODE_CFG_CRC16;
56 pCRC->SEED = CRC_SEED_CRC16;
57 break;
58
59 case CRC_POLY_CRC32:
60 pCRC->MODE = MODE_CFG_CRC32;
61 pCRC->SEED = CRC_SEED_CRC32;
62 break;
63
64 case CRC_POLY_CCITT:
65 default:
66 pCRC->MODE = MODE_CFG_CCITT;
67 pCRC->SEED = CRC_SEED_CCITT;
68 break;
69 }
70 }
71
72 /* Convenience function for computing a standard CCITT checksum from an 8-bit data block */
73 uint32_t IP_CRC_CRC8(IP_CRC_001_T *pCRC, const uint8_t *data, uint32_t bytes)
74 {
75 while (bytes > 0) {
76 IP_CRC_Write8(pCRC, *data);
77 data++;
78 bytes--;
79 }
80 return IP_CRC_ReadSum(pCRC);
81 }
82
83 /* Configure CRC engine and compute CRC16 checksum from 16-bit data */
84 uint32_t IP_CRC_CRC16(IP_CRC_001_T *pCRC, const uint16_t *data, uint32_t hwords)
85 {
86 while (hwords > 0) {
87 IP_CRC_Write16(pCRC, *data);
88 data++;
89 hwords--;
90 }
91 return IP_CRC_ReadSum(pCRC);
92 }
93
94 /* Configure CRC engine and compute CRC32 checksum from 32-bit data */
95 uint32_t IP_CRC_CRC32(IP_CRC_001_T *pCRC, const uint32_t *data, uint32_t words)
96 {
97 while (words > 0) {
98 IP_CRC_Write32(pCRC, *data);
99 data++;
100 words--;
101 }
102 return IP_CRC_ReadSum(pCRC);
103 }