Enable timer, use for delay functions

dougg3 · Sep 10, 2023 · 9df4cd0 · 9df4cd0
1 parent 6a9b75d
commit 9df4cd0
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Showing 2 changed files with 22 additions and 8 deletions.
diff --git a/hal/m258ke/board.c b/hal/m258ke/board.c
@@ -51,6 +51,12 @@ void Board_Init(void)
 	// Enable USB device controller
 	CLK->APBCLK0 |= CLK_APBCLK0_USBDCKEN_Msk;
 
+	// Enable timer 0
+	CLK->APBCLK0 |= CLK_APBCLK0_TMR0CKEN_Msk;
+
+	// Timer 0 clock source = 48 MHz HIRC
+	CLK->CLKSEL1 = (CLK->CLKSEL1 & (~(CLK_CLKSEL1_TMR0SEL_Msk))) | (7UL << CLK_CLKSEL1_TMR0SEL_Pos);
+
 	// Enable all GPIO
 	CLK->AHBCLK |=
 			CLK_AHBCLK_GPACKEN_Msk |
@@ -59,6 +65,9 @@ void Board_Init(void)
 			CLK_AHBCLK_GPDCKEN_Msk |
 			CLK_AHBCLK_GPECKEN_Msk |
 			CLK_AHBCLK_GPFCKEN_Msk;
+
+	// Start the timer, prescaler = 48, so 1 MHz
+	TIMER0->CTL = TIMER_CTL_CNTEN_Msk | (3UL << TIMER_CTL_OPMODE_Pos) | 47;
 }
 
 /** Determines if a brownout was detected at startup

diff --git a/hal/m258ke/hardware.h b/hal/m258ke/hardware.h
@@ -44,22 +44,27 @@ static inline void EnableInterrupts(void)
 	__enable_irq();
 }
 
-/** Blocks for the specified number of milliseconds
+/** Blocks for the specified number of microseconds
  *
- * @param ms The number of milliseconds to wait
+ * @param us The number of microseconds to wait
  */
-static inline void DelayMS(uint32_t ms)
+static inline void DelayUS(uint32_t us)
 {
-
+	const uint32_t startTime = TIMER0->CNT & 0xFFFFFFUL;
+	uint32_t nowTime;
+	do
+	{
+		nowTime = TIMER0->CNT & 0xFFFFFFUL;
+	} while (((nowTime - startTime) & 0xFFFFFFUL) < us);
 }
 
-/** Blocks for the specified number of microseconds
+/** Blocks for the specified number of milliseconds
  *
- * @param us The number of microseconds to wait
+ * @param ms The number of milliseconds to wait
  */
-static inline void DelayUS(uint32_t us)
+static inline void DelayMS(uint32_t ms)
 {
-
+	DelayUS(ms * 1000UL);
 }
 
 #endif /* HAL_M258KE_HARDWARE_H_ */