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Caching IDR pointer

This commit is contained in:
lacklustrlabs 2017-11-19 09:39:29 +01:00
parent 4a84203917
commit 0f6d90943a
1 changed files with 5 additions and 5 deletions
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10
STM32F1/cores/maple/stm32f1/wiring_pulse_f1.cpp
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@ -29,11 +29,11 @@
*/ */
uint32_t pulseIn( uint32_t pin, uint32_t state, uint32_t timeout ) uint32_t pulseIn( uint32_t pin, uint32_t state, uint32_t timeout )
{ {
// cache the reg map and bit of the pin in order to speed up the // cache the IDR address and bit of the pin in order to speed up the
// pulse width measuring loop and achieve finer resolution. calling // pulse width measuring loop and achieve finer resolution. calling
// digitalRead() instead yields much coarser resolution. // digitalRead() instead yields much coarser resolution.
const gpio_reg_map * const regs = digitalPinToPort(pin)->regs; __io uint32_t * const idr = portInputRegister(digitalPinToPort(pin));
const uint32_t bit = digitalPinToBitMask(pin); const uint32_t bit = digitalPinToBitMask(pin);
const uint32_t stateMask = (state ? bit:0); const uint32_t stateMask = (state ? bit:0);
@ -46,7 +46,7 @@ uint32_t pulseIn( uint32_t pin, uint32_t state, uint32_t timeout )
volatile uint32_t dummyWidth=0; volatile uint32_t dummyWidth=0;
// wait for any previous pulse to end // wait for any previous pulse to end
while ((regs->IDR & bit) == stateMask) { while ((*idr & bit) == stateMask) {
if (numloops++ == maxloops) { if (numloops++ == maxloops) {
return 0; return 0;
} }
@ -54,7 +54,7 @@ uint32_t pulseIn( uint32_t pin, uint32_t state, uint32_t timeout )
} }
// wait for the pulse to start // wait for the pulse to start
while ((regs->IDR & bit) != stateMask) { while ((*idr & bit) != stateMask) {
if (numloops++ == maxloops) { if (numloops++ == maxloops) {
return 0; return 0;
} }
@ -62,7 +62,7 @@ uint32_t pulseIn( uint32_t pin, uint32_t state, uint32_t timeout )
} }
// wait for the pulse to stop // wait for the pulse to stop
while ((regs->IDR & bit) == stateMask) { while ((*idr & bit) == stateMask) {
if (numloops++ == maxloops) { if (numloops++ == maxloops) {
return 0; return 0;
} }