Diff: libraries/tests/KL25Z/pit/main.cpp

Revision:

0:6c56fb4bc5f0

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libraries/tests/KL25Z/pit/main.cpp	Fri Nov 04 20:27:58 2016 +0000
@@ -0,0 +1,48 @@
+#include "mbed.h"
+
+extern "C" {
+volatile uint32_t msTicks;
+
+void SysTick_Handler(void) {
+    msTicks++;
+}
+
+void Delay(uint32_t dlyTicks) {
+    uint32_t curTicks;
+
+    curTicks = msTicks;
+    while ((msTicks - curTicks) < dlyTicks);
+}
+}
+
+int main() {
+    SysTick_Config(SystemCoreClock / 1000);
+
+    SIM->SCGC6 |= SIM_SCGC6_PIT_MASK;   // Clock PIT
+    PIT->MCR = 0;                       // Enable PIT
+
+    // Timer 1
+    PIT->CHANNEL[1].LDVAL = 0xFFFFFFFF;
+    PIT->CHANNEL[1].TCTRL = 0x0;                 // Disable Interrupts
+    PIT->CHANNEL[1].TCTRL |= PIT_TCTRL_CHN_MASK; // Chain to timer 0
+    PIT->CHANNEL[1].TCTRL |= PIT_TCTRL_TEN_MASK; // Start timer 1
+
+    // Timer 2
+    PIT->CHANNEL[0].LDVAL = 0xFFFFFFFF;
+    PIT->CHANNEL[0].TCTRL = PIT_TCTRL_TEN_MASK;  // Start timer 0, disable interrupts
+
+    DigitalOut led(LED_BLUE);
+    while (true) {
+        Delay(1000);
+        led = !led;
+
+        uint64_t ticks = (uint64_t)PIT->LTMR64H << 32;
+        ticks         |= (uint64_t)PIT->LTMR64L;
+        printf("ticks: 0x%x%x\n", (uint32_t)(ticks>>32), (uint32_t)(ticks & 0xFFFFFFFF));
+
+        ticks = (~ticks) / 24;
+        uint32_t us = (uint32_t)(0xFFFFFFFF & ticks);
+
+        printf("us   : 0x%x\n", us);
+    }
+}