1 /*
2 * @brief LPC15xx Cyclic Redundancy Check (CRC) Engine driver
3 *
4 * @note
5 * Copyright(C) NXP Semiconductors, 2013
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 #include "chip.h"
32
33 /*****************************************************************************
34 * Private types/enumerations/variables
35 ****************************************************************************/
36
37 /*****************************************************************************
38 * Public types/enumerations/variables
39 ****************************************************************************/
40
41 /*****************************************************************************
42 * Private functions
43 ****************************************************************************/
44
45 /*****************************************************************************
46 * Public functions
47 ****************************************************************************/
48
49 /* Initialize CRC engine */
Chip_CRC_Init(void)50 void Chip_CRC_Init(void)
51 {
52 Chip_Clock_EnablePeriphClock(SYSCTL_CLOCK_CRC);
53 Chip_SYSCTL_PeriphReset(RESET_CRC);
54 }
55
56 /* De-initialize CRC engine */
Chip_CRC_Deinit(void)57 void Chip_CRC_Deinit(void)
58 {
59 Chip_Clock_DisablePeriphClock(SYSCTL_CLOCK_CRC);
60 }
61
62 /* Sets up the CRC engine with defaults based on the polynomial to be used */
Chip_CRC_UseDefaultConfig(CRC_POLY_T poly)63 void Chip_CRC_UseDefaultConfig(CRC_POLY_T poly)
64 {
65 switch (poly) {
66 case CRC_POLY_CRC16:
67 Chip_CRC_UseCRC16();
68 break;
69
70 case CRC_POLY_CRC32:
71 Chip_CRC_UseCRC32();
72 break;
73
74 case CRC_POLY_CCITT:
75 default:
76 Chip_CRC_UseCCITT();
77 break;
78 }
79 }
80
81 /* configure CRC engine and compute CCITT checksum from 8-bit data */
Chip_CRC_CRC8(const uint8_t * data,uint32_t bytes)82 uint32_t Chip_CRC_CRC8(const uint8_t *data, uint32_t bytes)
83 {
84 Chip_CRC_UseCCITT();
85 while (bytes > 0) {
86 Chip_CRC_Write8(*data);
87 data++;
88 bytes--;
89 }
90
91 return Chip_CRC_Sum();
92 }
93
94 /* Convenience function for computing a standard CRC16 checksum from 16-bit data block */
Chip_CRC_CRC16(const uint16_t * data,uint32_t hwords)95 uint32_t Chip_CRC_CRC16(const uint16_t *data, uint32_t hwords)
96 {
97 Chip_CRC_UseCRC16();
98 while (hwords > 0) {
99 Chip_CRC_Write16(*data);
100 data++;
101 hwords--;
102 }
103
104 return Chip_CRC_Sum();
105 }
106
107 /* Convenience function for computing a standard CRC32 checksum from 32-bit data block */
Chip_CRC_CRC32(const uint32_t * data,uint32_t words)108 uint32_t Chip_CRC_CRC32(const uint32_t *data, uint32_t words)
109 {
110 Chip_CRC_UseCRC32();
111 while (words > 0) {
112 Chip_CRC_Write32(*data);
113 data++;
114 words--;
115 }
116
117 return Chip_CRC_Sum();
118 }
119