1 /*
2 * @brief Windowed Watchdog Timer (WWDT) example
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
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 * @brief watchdog timer Interrupt Handler
51 * @return Nothing
52 * @note Handles watchdog timer warning and timeout events
53 */
WDT_IRQHandler(void)54 void WDT_IRQHandler(void)
55 {
56 uint32_t wdtStatus = Chip_WWDT_GetStatus(LPC_WWDT);
57
58 Board_LED_Toggle(0);
59
60 /* The chip will reset before this happens, but if the WDT doesn't
61 have WWDT_WDMOD_WDRESET enabled, this will hit once */
62 if (wdtStatus & WWDT_WDMOD_WDTOF) {
63 /* A watchdog feed didn't occur prior to window timeout */
64 Chip_WWDT_UnsetOption(LPC_WWDT, WWDT_WDMOD_WDEN); /* Stop WDT */
65 Chip_WWDT_ClearStatusFlag(LPC_WWDT, WWDT_WDMOD_WDTOF);
66 Chip_WWDT_Start(LPC_WWDT); /* Needs restart */
67 }
68
69 /* Handle warning interrupt */
70 if (wdtStatus & WWDT_WDMOD_WDINT) {
71 /* A watchdog feed didn't occur prior to warning timeout */
72 Chip_WWDT_ClearStatusFlag(LPC_WWDT, WWDT_WDMOD_WDINT);
73 Chip_WWDT_Feed(LPC_WWDT);
74 }
75 }
76
77 /**
78 * @brief Application Main entry point
79 * @return Nothing (This will not return)
80 */
main(void)81 int main(void)
82 {
83 uint32_t wdtFreq;
84
85 SystemCoreClockUpdate();
86 Board_Init();
87 Board_LED_Set(0, false);
88
89 /* Enable the WDT oscillator */
90 Chip_SYSCTL_PowerUp(SYSCTL_POWERDOWN_WDTOSC_PD);
91
92 /* The WDT divides the input frequency into it by 4 */
93 wdtFreq = Chip_Clock_GetWDTOSCRate() / 4;
94
95 /* Initialize WWDT (also enables WWDT clock) */
96 Chip_WWDT_Init(LPC_WWDT);
97
98 /* Set watchdog feed time constant to approximately 2s
99 Set watchdog warning time to 512 ticks after feed time constant
100 Set watchdog window time to 3s */
101 Chip_WWDT_SetTimeOut(LPC_WWDT, wdtFreq * 2);
102 Chip_WWDT_SetWarning(LPC_WWDT, 512);
103 Chip_WWDT_SetWindow(LPC_WWDT, wdtFreq * 3);
104
105 /* Configure WWDT to reset on timeout */
106 Chip_WWDT_SetOption(LPC_WWDT, WWDT_WDMOD_WDRESET);
107
108 /* Clear watchdog warning and timeout interrupts */
109 Chip_WWDT_ClearStatusFlag(LPC_WWDT, WWDT_WDMOD_WDTOF | WWDT_WDMOD_WDINT);
110
111 /* Power everything up except for ADC, USB and temp sensor on wake up from
112 deep sleep. */
113 Chip_SYSCTL_SetWakeup(~(SYSCTL_SLPWAKE_IRCOUT_PD | SYSCTL_SLPWAKE_IRC_PD |
114 SYSCTL_SLPWAKE_FLASH_PD | SYSCTL_SLPWAKE_SYSOSC_PD |
115 SYSCTL_SLPWAKE_SYSPLL_PD | SYSCTL_SLPWAKE_WDTOSC_PD));
116 /* Allow WDT to wake from deep sleep. */
117 Chip_SYSCTL_EnableERP0PeriphWakeup(SYSCTL_ERP0_WAKEUP_WDTINT);
118
119 /* Clear and enable watchdog interrupt */
120 NVIC_ClearPendingIRQ(WWDT_IRQn);
121 NVIC_EnableIRQ(WWDT_IRQn);
122
123 /* Start watchdog */
124 Chip_WWDT_Start(LPC_WWDT);
125
126 /* Sleep until WDT needs servicing */
127 while (1) {
128 LPC_PWRD_API->power_mode_configure(PMU_DEEP_SLEEP, ~PMU_PD_WDOSC);
129 __WFI();
130 }
131
132 return 0;
133 }
134