main.cpp

00001 #include "mbed.h"
00002 
00003 InterruptIn button(USER_BUTTON0);
00004 DigitalOut led1(LED1);
00005 Thread * pTestTask = NULL;
00006 
00007 static void idle_hook(void) {
00008     // Do the following instead of "__WFI()"
00009     __SEV();
00010     __WFE();
00011     __WFE();
00012 }
00013 
00014 void SoftwareStandby(void) {
00015     volatile uint32_t dummy_32;
00016     volatile uint8_t dummy_8;
00017 
00018     core_util_critical_section_enter();
00019 
00020     // Set the standby_mode_en bit of the power control register in the PL310 to 1.
00021     L2C.REG15_POWER_CTRL = 0x00000001uL;
00022     dummy_32 = L2C.REG15_POWER_CTRL;
00023 
00024     // Clear the TME bit in the watchdog timer control/status register (WTCSR) of the watchdog timer to 0 to stop the watchdog timer.
00025     WDT.WTCSR = 0xA518;
00026     WDT.WTCNT = 0x5A00;
00027     WDT.WTCSR = 0xA51D;  // CKS[2:0] = b'101 : 1/1024 x P0 (7.8ms)
00028 
00029     CPG.STBCR1 = 0x80;
00030     dummy_8 = CPG.STBCR1;
00031 
00032     __WFI();
00033 
00034     core_util_critical_section_exit();
00035 }
00036 
00037 static void interrupt_button(void) {
00038 #if(0)  // It may or may not be present.
00039     if (pTestTask != NULL) {
00040         pTestTask->signal_set(1);
00041     }
00042 #endif
00043 }
00044 
00045 void test_task(void) {
00046     int test_cnt = 0;
00047 
00048     button.fall(&interrupt_button);
00049     button.rise(&interrupt_button);
00050 
00051     while (true) {
00052         SoftwareStandby();
00053 #if(0)  // It may or may not be present.
00054         // It becomes sleep during idle task.
00055         Thread::signal_wait(1);
00056 #endif
00057         led1 = !led1;
00058         printf("%d\r\n", test_cnt++);
00059         ThisThread::sleep_for(5);  // Wait for output completion of printf().
00060     }
00061 }
00062 
00063 int main() {
00064     Thread::attach_idle_hook(idle_hook);
00065     pTestTask = new Thread();
00066     pTestTask->start(test_task);
00067 }