add firmware

drv/tick.cpp

@@ -0,0 +1,36 @@
+#include "stm32g4xx.h"
+
+#include "tick.h"
+
+static unsigned long Tick = 0;
+
+extern "C" void SysTick_Handler()
+{
+  Tick++;
+}
+//------------------------------------------------------------------------------
+
+void TICK_Init()
+{
+  SysTick->LOAD = SystemCoreClock / 1000;
+  SysTick->VAL = 0UL;
+  SysTick->CTRL = SysTick_CTRL_CLKSOURCE_Msk | SysTick_CTRL_TICKINT_Msk | SysTick_CTRL_ENABLE_Msk;
+
+  NVIC_SetPriority(SysTick_IRQn, 0);
+}
+//------------------------------------------------------------------------------
+
+unsigned long TICK_GetCount() // ms
+{
+  return Tick;
+}
+//------------------------------------------------------------------------------
+
+
+void Tick_Delay(unsigned long ms)
+{
+    const unsigned long start = Tick;
+    while ((Tick - start) < ms) {
+        __NOP();                     
+    }
+}