track millis - no magic

teensy4/EventResponder.cpp

@@ -339,7 +339,7 @@ extern "C" volatile uint32_t systick_millis_count;
 extern "C" volatile uint32_t systick_cycle_count;
 extern "C" void systick_isr(void)
 {
-	systick_cycle_count += F_CPU_ACTUAL/1000;
+	systick_cycle_count = ARM_DWT_CYCCNT;
 	systick_millis_count++;
 	MillisTimer::runFromTimer();
 }