Improve README and doxygen comments

src/hal/delay.cpp

@@ -1,7 +1,10 @@
 #include <sta/hal/delay.hpp>
 #ifdef STA_HAL_DELAY_ENABLE
 
-#include <main.h>
+#include <sta/assert.hpp>
+#include <sta/hal.hpp>
+#include <sta/lang.hpp>
+#include <sta/hal/clocks.hpp>
 
 
 namespace sta
@@ -24,6 +27,36 @@ namespace sta
 		__HAL_TIM_SET_COUNTER(&STA_HAL_DELAY_US_TIM, 0);
 		while (__HAL_TIM_GET_COUNTER(&STA_HAL_DELAY_US_TIM) < us);
 	}
+
+
+	bool isValidDelayUsTIM()
+	{
+		// Get PCLK multiplier for TIM clock
+		uint32_t pclkMul = 1;
+		switch (STA_HAL_DELAY_US_TIM.Init.ClockDivision)
+		{
+		case TIM_CLOCKDIVISION_DIV1:
+			pclkMul = 1;
+			break;
+		case TIM_CLOCKDIVISION_DIV2:
+			pclkMul = 2;
+			break;
+		case TIM_CLOCKDIVISION_DIV4:
+			pclkMul = 4;
+			break;
+		default:
+			STA_ASSERT(false);
+			STA_UNREACHABLE();
+		}
+
+		// Calculate TIM clock frequency
+		uint32_t clkFreq = pclkMul * STA_HAL_GET_HANDLE_PCLK_FREQ_FN(STA_HAL_DELAY_US_TIM)();
+		// Calculate update frequency based on prescaler value
+		uint32_t updateFreq = clkFreq / STA_HAL_DELAY_US_TIM.Init.Prescaler;
+
+		// TIM must have at least microsecond precision (>= 1 MHz frequency)
+		return (updateFreq == 1000000);
+	}
 } // namespace sta
 
 #endif // STA_HAL_DELAY_US_TIM