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watchdog.c
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1 /*
2 * @brief WWDT 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
70 /*****************************************************************************
71 * Private types/enumerations/variables
72 ****************************************************************************/
73 #define FEED_ON_SYSTICKINT 0
74 #define FEED_ON_WARNINT 1
75 #define NO_FEED 2
76
77 static volatile int wdtFeedState;
78 static volatile bool On = false;
79
80 /*****************************************************************************
81 * Public types/enumerations/variables
82 ****************************************************************************/
83
84 /*****************************************************************************
85 * Private functions
86 ****************************************************************************/
87
88 /* WDT interrupt handler */
89 static void wdt_handle(void) {
90 uint32_t wdtStatus = Chip_WWDT_GetStatus(LPC_WWDT);
91
92 On = (bool) !On;
93
94 /* The chip will reset before this happens, but if the WDT doesn't
95 have WWDT_MOD_WDRESET enabled, this will hit once */
96 if (wdtStatus & WWDT_WDMOD_WDTOF) {
97 /* A watchdog feed didn't occur prior to window timeout */
98 Chip_WWDT_ClearStatusFlag(LPC_WWDT, WWDT_WDMOD_WDTOF);
99
100 if (wdtFeedState == NO_FEED) {
101 Chip_WWDT_Start(LPC_WWDT); /* Needs restart */
102 }
103 }
104 #if !defined(CHIP_LPC175X_6X)
105 /* Handle warning interrupt */
106 if (wdtStatus & WWDT_WDMOD_WDINT) {
107 /* A watchdog feed didn't occur prior to warning timeout */
108 Chip_WWDT_ClearStatusFlag(LPC_WWDT, WWDT_WDMOD_WDINT);
109
110 if (wdtFeedState == FEED_ON_WARNINT) {
111 Chip_WWDT_Feed(LPC_WWDT);
112 }
113 }
114 #endif
115 }
116
117 /*****************************************************************************
118 * Public functions
119 ****************************************************************************/
120
126 void WDT_IRQHandler(void)
127 {
128 wdt_handle();
129 }
130
136 void SysTick_Handler(void)
137 {
138 if (wdtFeedState == FEED_ON_SYSTICKINT) {
139 On = (bool) !On;
140 Chip_WWDT_Feed(LPC_WWDT);
141 }
142 }
143
148 int main(void)
149 {
150 uint8_t ch;
151 uint32_t wdtFreq;
152
153 Board_Init();
154
155 /* Watchdog will be fed on each watchdog interrupt */
156 wdtFeedState = FEED_ON_SYSTICKINT;
157
158 /* Initialize WWDT and event router */
159 Chip_WWDT_Init(LPC_WWDT);
160
161 #if defined(WATCHDOG_CLKSEL_SUPPORT)
162 Chip_WWDT_SelClockSource(LPC_WWDT, WWDT_CLKSRC_WATCHDOG_PCLK);
163 wdtFreq = Chip_Clock_GetPeripheralClockRate(SYSCTL_PCLK_WDT) / 4;
164 #else
165 wdtFreq = WDT_OSC;
166 #endif
167
168 /* Set watchdog feed time constant to 0.1s */
169 Chip_WWDT_SetTimeOut(LPC_WWDT, wdtFreq / 10);
170 #if !defined(CHIP_LPC175X_6X)
171 /* Set watchdog warning time to 512 ticks after feed time constant
172 Set watchdog window time to 0.9s */
173 Chip_WWDT_SetWarning(LPC_WWDT, 512);
174 Chip_WWDT_SetWindow(LPC_WWDT, wdtFreq - (wdtFreq / 10));
175 #endif
177 /* Configure WWDT to reset on timeout */
178 Chip_WWDT_SetOption(LPC_WWDT, WWDT_WDMOD_WDRESET);
179
180 /* Clear watchdog warning and timeout interrupts */
181 Chip_WWDT_ClearStatusFlag(LPC_WWDT, WWDT_WDMOD_WDTOF | WWDT_WDMOD_WDINT);
182
183 /* Start watchdog */
184 Chip_WWDT_Start(LPC_WWDT);
185
186 /* Setup Systick for a 20Hz tick rate. Systick clock is clocked at
187 CPU core clock speed */
188 SysTick_Config(Chip_Clock_GetSystemClockRate() / 20);
189
190 /* Enable watchdog interrupt */
191 NVIC_ClearPendingIRQ(WDT_IRQn);
192 NVIC_EnableIRQ(WDT_IRQn);
193
194 /* Watchdog test options */
195 DEBUGOUT("Press '1' to enable watchdog feed on systick interrupt\n\r");
196 #if !defined(CHIP_LPC175X_6X)
197 DEBUGOUT("Press '2' to enable watchdog feed on warning interrupt\n\r");
198 #endif
199 DEBUGOUT("Press '3' to disable watchdog feed (will reset device)\n\r");
200
201 while (1) {
202 do {
203 ch = DEBUGIN();
204 Board_LED_Set(0, On);
205 } while ((ch < '1') || (ch > '4'));
206
207 switch (ch) {
208 case '1':
209 default:
210 wdtFeedState = FEED_ON_SYSTICKINT;
211 DEBUGOUT("Watchdog feed on systick interrupt\r\n");
212 break;
213 #if !defined(CHIP_LPC175X_6X)
214 case '2':
215 wdtFeedState = FEED_ON_WARNINT;
216 DEBUGOUT("Watchdog feed on warning interrupt\r\n");
217 break;
218 #endif
219 case '3':
220 wdtFeedState = NO_FEED;
221 DEBUGOUT("No feeding - board will reset\r\n");
222 break;
223 }
224 }
225 }
226