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Update the delay functions and change the default pinmap for character displays (#7434)

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This commit is contained in:
Chris Pepper
2017-08-05 01:20:01 +01:00
committed by Scott Lahteine
parent 105324b85b
commit 9a950e3a5a
2 changed files with 22 additions and 9 deletions
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25
Marlin/src/HAL/HAL_LPC1768/arduino.cpp
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@ -43,17 +43,28 @@ uint32_t millis() {
return _millis;
}
//todo: recheck all of this
void delayMicroseconds(uint32_t us) {
if (us < 2) return; // function jump, compare, return about 1us
us--;
static const int nop_factor = (SystemCoreClock / 10000000); // measured accurate at 10us
static const int nop_factor = (SystemCoreClock / 11000000);
static volatile int loops = 0;
if (us < 20) { // burn cycles
//previous ops already burned most of 1us, burn the rest
loops = nop_factor / 4; //measured at 1us
while (loops > 0) --loops;
if (us < 2) return;
us--;
//redirect to delay for large values, then set new delay to remainder
if (us > 1000) {
delay(us / 1000);
us = us % 1000;
}
if (us < 5) { // burn cycles, time in interrupts will not be taken into account
loops = us * nop_factor;
while (loops > 0) --loops;
}
else { // poll systick
else { // poll systick, more accurate through interrupts
int32_t start = SysTick->VAL;
int32_t load = SysTick->LOAD;
int32_t end = start - (load / 1000) * us;
@ -67,6 +78,8 @@ void delayMicroseconds(uint32_t us) {
extern "C" void delay(int msec) {
volatile int32_t end = _millis + msec;
SysTick->VAL = SysTick->LOAD; // reset systick counter so next systick is in exactly 1ms
// this could extend the time between systicks by upto 1ms
while (_millis < end) __WFE();
}