仓库迁移

source/rt_thread/core_delay.c

@@ -0,0 +1,91 @@
+#include "stm32f4xx.h"
+#include "core_delay.h"
+#include "rtthread.h"
+#include <rthw.h>
+
+
+#define DWT_CR      *(__IO uint32_t *)0xE0001000
+#define DWT_CYCCNT  *(__IO uint32_t *)0xE0001004
+#define DEM_CR      *(__IO uint32_t *)0xE000EDFC
+
+#define DEM_CR_TRCENA (1 << 24)
+#define DWT_CR_CYCCNTENA (1 << 0)
+
+
+
+
+//<2F><>ȡϵͳ<CFB5><CDB3>Ƶ
+static uint32_t get_sys_clocks_freq (void)
+{
+	RCC_ClocksTypeDef t={0};
+	RCC_GetClocksFreq (&t);
+	return t.SYSCLK_Frequency;
+}
+
+
+
+
+
+int delay_init(void)
+{
+  DEM_CR |= (uint32_t)DEM_CR_TRCENA;
+  DWT_CYCCNT = (uint32_t)0u;
+  DWT_CR |= (uint32_t)DWT_CR_CYCCNTENA;
+  return 0;
+}
+
+
+static uint32_t delay_get_cnt(void)
+{
+  return ((uint32_t)DWT_CYCCNT);
+}
+
+static uint32_t delay_get_tick(void)
+{
+  return ((uint32_t)DWT_CYCCNT*1000/get_sys_clocks_freq());
+}
+
+
+
+// <20><><EFBFBD><EFBFBD>1ms<6D>ľ<EFBFBD>ȷ<EFBFBD><C8B7>ʱ
+void delay_us(uint32_t us)
+{
+  uint32_t ticks;
+  uint32_t told, tnow, tcnt=0;
+
+  /* <20><>Ҫ<EFBFBD>Ľ<EFBFBD><C4BD><EFBFBD><EFBFBD><EFBFBD> */
+  ticks = us * (get_sys_clocks_freq() / 1000000);
+  tcnt = 0;
+  told = (uint32_t)delay_get_cnt();
+
+  while (1) 
+  {
+    tnow = (uint32_t)delay_get_cnt();
+    if (tnow != told) 
+    {
+      /* 32 λ<><CEBB><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ǵ<EFBFBD><C7B5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD> */
+      if (tnow > told) 
+      {
+        tcnt += tnow - told;
+      }
+      /* <20><><EFBFBD><EFBFBD>װ<EFBFBD><D7B0> */
+      else 
+      {
+        tcnt += UINT32_MAX - told + tnow;
+      }
+
+      told = tnow;
+
+      /*ʱ<>䳬<EFBFBD><E4B3AC>/<2F><><EFBFBD><EFBFBD>Ҫ<EFBFBD>ӳٵ<D3B3>ʱ<EFBFBD><CAB1>,<2C><><EFBFBD>˳<EFBFBD> */
+      if (tcnt >= ticks)break;
+    }
+  }
+}
+
+
+// ʵ<><CAB5>rt_thread <20><>us<75><73><EFBFBD><EFBFBD>ʱ
+void rt_hw_us_delay(rt_uint32_t us)
+{
+  delay_us(us);
+}
+