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#ifndef __INC_CLOCKLESS_ARM_K20_H
#define __INC_CLOCKLESS_ARM_K20_H
FASTLED_NAMESPACE_BEGIN
// Definition for a single channel clockless controller for the k20 family of chips, like that used in the teensy 3.0/3.1
// See clockless.h for detailed info on how the template parameters are used.
#if defined(FASTLED_TEENSY3)
#define FASTLED_HAS_CLOCKLESS 1
template <int DATA_PIN, int T1, int T2, int T3, EOrder RGB_ORDER = RGB, int XTRA0 = 0, bool FLIP = false, int WAIT_TIME = 50>
class ClocklessController : public CPixelLEDController<RGB_ORDER> {
typedef typename FastPin<DATA_PIN>::port_ptr_t data_ptr_t;
typedef typename FastPin<DATA_PIN>::port_t data_t;
data_t mPinMask;
data_ptr_t mPort;
CMinWait<WAIT_TIME> mWait;
public:
virtual void init() {
FastPin<DATA_PIN>::setOutput();
mPinMask = FastPin<DATA_PIN>::mask();
mPort = FastPin<DATA_PIN>::port();
}
virtual uint16_t getMaxRefreshRate() const { return 400; }
protected:
virtual void showPixels(PixelController<RGB_ORDER> & pixels) {
mWait.wait();
if(!showRGBInternal(pixels)) {
sei(); delayMicroseconds(WAIT_TIME); cli();
showRGBInternal(pixels);
}
mWait.mark();
}
template<int BITS> __attribute__ ((always_inline)) inline static void writeBits(register uint32_t & next_mark, register data_ptr_t port, register data_t hi, register data_t lo, register uint8_t & b) {
for(register uint32_t i = BITS-1; i > 0; i--) {
while(ARM_DWT_CYCCNT < next_mark);
next_mark = ARM_DWT_CYCCNT + (T1+T2+T3);
FastPin<DATA_PIN>::fastset(port, hi);
if(b&0x80) {
while((next_mark - ARM_DWT_CYCCNT) > (T3+(2*(F_CPU/24000000))));
FastPin<DATA_PIN>::fastset(port, lo);
} else {
while((next_mark - ARM_DWT_CYCCNT) > (T2+T3+(2*(F_CPU/24000000))));
FastPin<DATA_PIN>::fastset(port, lo);
}
b <<= 1;
}
while(ARM_DWT_CYCCNT < next_mark);
next_mark = ARM_DWT_CYCCNT + (T1+T2+T3);
FastPin<DATA_PIN>::fastset(port, hi);
if(b&0x80) {
while((next_mark - ARM_DWT_CYCCNT) > (T3+(2*(F_CPU/24000000))));
FastPin<DATA_PIN>::fastset(port, lo);
} else {
while((next_mark - ARM_DWT_CYCCNT) > (T2+T3+(2*(F_CPU/24000000))));
FastPin<DATA_PIN>::fastset(port, lo);
}
}
// This method is made static to force making register Y available to use for data on AVR - if the method is non-static, then
// gcc will use register Y for the this pointer.
static uint32_t showRGBInternal(PixelController<RGB_ORDER> pixels) {
// Get access to the clock
ARM_DEMCR |= ARM_DEMCR_TRCENA;
ARM_DWT_CTRL |= ARM_DWT_CTRL_CYCCNTENA;
ARM_DWT_CYCCNT = 0;
register data_ptr_t port = FastPin<DATA_PIN>::port();
register data_t hi = *port | FastPin<DATA_PIN>::mask();;
register data_t lo = *port & ~FastPin<DATA_PIN>::mask();;
*port = lo;
// Setup the pixel controller and load/scale the first byte
pixels.preStepFirstByteDithering();
register uint8_t b = pixels.loadAndScale0();
cli();
uint32_t next_mark = ARM_DWT_CYCCNT + (T1+T2+T3);
while(pixels.has(1)) {
pixels.stepDithering();
#if (FASTLED_ALLOW_INTERRUPTS == 1)
cli();
// if interrupts took longer than 45µs, punt on the current frame
if(ARM_DWT_CYCCNT > next_mark) {
if((ARM_DWT_CYCCNT-next_mark) > ((WAIT_TIME-INTERRUPT_THRESHOLD)*CLKS_PER_US)) { sei(); return 0; }
}
hi = *port | FastPin<DATA_PIN>::mask();
lo = *port & ~FastPin<DATA_PIN>::mask();
#endif
// Write first byte, read next byte
writeBits<8+XTRA0>(next_mark, port, hi, lo, b);
b = pixels.loadAndScale1();
// Write second byte, read 3rd byte
writeBits<8+XTRA0>(next_mark, port, hi, lo, b);
b = pixels.loadAndScale2();
// Write third byte, read 1st byte of next pixel
writeBits<8+XTRA0>(next_mark, port, hi, lo, b);
b = pixels.advanceAndLoadAndScale0();
#if (FASTLED_ALLOW_INTERRUPTS == 1)
sei();
#endif
};
sei();
return ARM_DWT_CYCCNT;
}
};
#endif
FASTLED_NAMESPACE_END
#endif