1 /*
2 * @brief Blinky example using timers and sysTick
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 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 #include <stdio.h>
34
35 /*****************************************************************************
36 * Private types/enumerations/variables
37 ****************************************************************************/
38
39 #define TICKRATE_HZ1 (15) /* 15 ticks per second */
40
41 /*****************************************************************************
42 * Public types/enumerations/variables
43 ****************************************************************************/
44
45 /*****************************************************************************
46 * Private functions
47 ****************************************************************************/
48
49 /*****************************************************************************
50 * Public functions
51 ****************************************************************************/
52
53 /**
54 * @brief Handle interrupt from SysTick timer
55 * @return Nothing
56 */
SysTick_Handler(void)57 void SysTick_Handler(void)
58 {
59 Board_LED_Toggle(0);
60 Board_LED_Toggle(1);
61 }
62
63 /**
64 * @brief main routine for blinky example
65 * @return Function should not exit.
66 */
main(void)67 int main(void)
68 {
69 uint32_t sysTickRate;
70
71 SystemCoreClockUpdate();
72 Board_Init();
73 Board_LED_Set(0, false);
74 Board_LED_Set(1, true);
75
76 /* The sysTick counter only has 24 bits of precision, so it will
77 overflow quickly with a fast core clock. You can alter the
78 sysTick divider to generate slower sysTick clock rates. */
79 Chip_Clock_SetSysTickClockDiv(1);
80
81 /* A SysTick divider is present that scales the sysTick rate down
82 from the core clock. Using the SystemCoreClock variable as a
83 rate reference for the SysTick_Config() function won't work,
84 so get the sysTick rate by calling Chip_Clock_GetSysTickClockRate() */
85 sysTickRate = Chip_Clock_GetSysTickClockRate();
86
87 /* Enable and setup SysTick Timer at a periodic rate */
88 SysTick_Config(sysTickRate / TICKRATE_HZ1);
89
90 /* LEDs toggle in interrupt handlers */
91 while (1) {
92 __WFI();
93 }
94
95 return 0;
96 }
97