LPCOpen Platform  v1.03
LPCOpen Platform for NXP LPC Microcontrollers
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crc.c
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1 /*
2  * @brief Cyclic Redundancy Check (CRC) generator example.
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 licensor 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 "board.h"
33 
59 /*****************************************************************************
60  * Private types/enumerations/variables
61  ****************************************************************************/
62 
63 /* CRC data test patterns */
64 static const uint8_t bytes[] = {0x38, 0x38, 0x38, 0x38};
65 static const uint16_t words[] = {0x3534, 0x3534, 0x3534, 0x3534};
66 static const uint32_t dwords[] = {0x33323130, 0x33323130, 0x33323130, 0x33323130};
67 static const uint32_t expect[] = {0x56AB, 0x7A89, 0xD7D6, 0x7D27, 0xA6669D7D};
68 
69 #define TICKRATE_HZ (10) /* 10 ticks per second */
70 static volatile uint32_t ticks;
71 
72 /*****************************************************************************
73  * Public types/enumerations/variables
74  ****************************************************************************/
75 
76 /*****************************************************************************
77  * Private functions
78  ****************************************************************************/
79 
80 /*****************************************************************************
81  * Public functions
82  ****************************************************************************/
83 
88 void SysTick_Handler(void)
89 {
90  ticks++;
91  __SEV();
92 }
93 
99 int main(void)
100 {
101  uint32_t result[6], gencrc;
102 
103  /* Board Initialization */
104  Board_Init();
105 
106  /* Chip Initialization */
107  Chip_CRC_Init();
108 
109  /* Enable SysTick Timer */
110  SysTick_Config(SystemCoreClock / TICKRATE_HZ);
111 
112  /* Loop tests with occasional forced error */
113  while (1) {
114  result[0] = Chip_CRC_CRC8(&bytes[0], 1);
115  result[1] = Chip_CRC_CRC8(bytes, (sizeof(bytes) / sizeof(bytes[0])));
116  result[2] = Chip_CRC_CRC16(&words[0], 1);
117  if (ticks % 2 == 0) {
118  /* introduce bit errors on every other tick */
119  result[2] -= 1;
120  }
121  result[3] = Chip_CRC_CRC16(words, (sizeof(words) / sizeof(words[0])));
122  result[4] = Chip_CRC_CRC32(&dwords[0], 1);
123  result[5] = Chip_CRC_CRC32(dwords, (sizeof(dwords) / sizeof(dwords[0])));
124 
125  gencrc = Chip_CRC_CRC32((uint32_t *) result, 5);
126  result[0] = Chip_CRC_CRC32((uint32_t *) expect, 5);
127  if (result[0] != gencrc) {
128  Board_LED_Set(0, true);
129  }
130  else {
131  Board_LED_Set(0, false);
132  }
133 
134  /* Wait for tick */
135  __WFE();
136  }
137  return 0;
138 }
139