Caching IDR pointer
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4a84203917
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@ -29,11 +29,11 @@
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*/
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uint32_t pulseIn( uint32_t pin, uint32_t state, uint32_t timeout )
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{
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// cache the reg map and bit of the pin in order to speed up the
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// cache the IDR address and bit of the pin in order to speed up the
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// pulse width measuring loop and achieve finer resolution. calling
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// digitalRead() instead yields much coarser resolution.
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const gpio_reg_map * const regs = digitalPinToPort(pin)->regs;
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__io uint32_t * const idr = portInputRegister(digitalPinToPort(pin));
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const uint32_t bit = digitalPinToBitMask(pin);
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const uint32_t stateMask = (state ? bit:0);
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@ -46,7 +46,7 @@ uint32_t pulseIn( uint32_t pin, uint32_t state, uint32_t timeout )
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volatile uint32_t dummyWidth=0;
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// wait for any previous pulse to end
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while ((regs->IDR & bit) == stateMask) {
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while ((*idr & bit) == stateMask) {
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if (numloops++ == maxloops) {
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return 0;
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}
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@ -54,7 +54,7 @@ uint32_t pulseIn( uint32_t pin, uint32_t state, uint32_t timeout )
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}
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// wait for the pulse to start
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while ((regs->IDR & bit) != stateMask) {
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while ((*idr & bit) != stateMask) {
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if (numloops++ == maxloops) {
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return 0;
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}
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@ -62,7 +62,7 @@ uint32_t pulseIn( uint32_t pin, uint32_t state, uint32_t timeout )
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}
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// wait for the pulse to stop
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while ((regs->IDR & bit) == stateMask) {
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while ((*idr & bit) == stateMask) {
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if (numloops++ == maxloops) {
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return 0;
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}
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