Merge pull request sipeed#11 from ReinForce-II/fix_millis_and_micros

fix millis and micros

Author: bitsk

cores/arduino/Common.h

@@ -122,8 +122,8 @@ int analogRead(pin_size_t pinNumber);
 void analogReference(AnalogReferenceMode mode);
 void analogWrite(pin_size_t pinNumber, int value);
 
-unsigned long millis(void);
-unsigned long micros(void);
+uint64_t millis(void);
+uint64_t micros(void);
 void delay(unsigned long);
 void delayMicroseconds(unsigned int us);
 unsigned long pulseIn(pin_size_t pin, uint8_t state, unsigned long timeout);

cores/arduino/wiring.c

@@ -1,12 +1,12 @@
 #include "Arduino.h"
 #include "gd32vf103.h"
 
-unsigned long millis(void){
-    return (unsigned long)(get_timer_value() * (SystemCoreClock/4000.0));
+uint64_t millis(void){
+    return (uint64_t)(get_timer_value() * (4000.F / SystemCoreClock));
 }
 
-unsigned long micros(void){
-    return (unsigned long)(get_timer_value() * (SystemCoreClock/4000000.0));
+uint64_t micros(void){
+    return (uint64_t)(get_timer_value() * (4000000.F / SystemCoreClock));
 }
 
 void delay(unsigned long dwMs){