TMCStepper/_t_m_c__platforms_8h_source.html

#if defined(ARDUINO_ARCH_AVR) // 125kHz

  typedef volatile uint8_t* fastio_reg;

  typedef uint8_t fastio_bm;

  #define getPort(P) digitalPinToPort(P)

  #define writeMOSI_H *mosi_register |= mosi_bm

  #define writeMOSI_L *mosi_register &= ~mosi_bm

  #define writeSCK_H *sck_register |= sck_bm

  #define writeSCK_L *sck_register &= ~sck_bm

  #define readMISO *miso_register & miso_bm

#elif defined(ARDUINO_ARCH_SAM) // DUE:700kHz

  // by stimmer https://forum.arduino.cc/index.php?topic=129868.msg980466#msg980466

  #define writeMOSI_H g_APinDescription[mosi_pin].pPort -> PIO_SODR = g_APinDescription[mosi_pin].ulPin

  #define writeMOSI_L g_APinDescription[mosi_pin].pPort -> PIO_CODR = g_APinDescription[mosi_pin].ulPin

  #define writeSCK_H g_APinDescription[sck_pin].pPort -> PIO_SODR = g_APinDescription[sck_pin].ulPin

  #define writeSCK_L g_APinDescription[sck_pin].pPort -> PIO_CODR = g_APinDescription[sck_pin].ulPin

  #define readMISO PIO_Get( g_APinDescription[miso_pin].pPort, PIO_INPUT, g_APinDescription[miso_pin].ulPin )

#elif defined(TARGET_LPC1768)

  //typedef volatile LPC_GPIO_TypeDef* fastio_reg;

  //typedef uint32_t fastio_bm;

  #define writeMOSI_H LPC176x::gpio_set(mosi_pin)

  #define writeMOSI_L LPC176x::gpio_clear(mosi_pin)

  #define writeSCK_H LPC176x::delay_ns(240); LPC176x::gpio_set(sck_pin)

  #define writeSCK_L LPC176x::delay_ns(240); LPC176x::gpio_clear(sck_pin)

  #define readMISO LPC176x::gpio_get(miso_pin)

#elif defined(__STM32F1__) || defined(TARGET_STM32F1)

  #define writeMOSI_H digitalWrite(mosi_pin, HIGH)

  #define writeMOSI_L digitalWrite(mosi_pin, LOW)

  #define writeSCK_H digitalWrite(sck_pin, HIGH)

  #define writeSCK_L digitalWrite(sck_pin, LOW)

  #define readMISO digitalRead(miso_pin)

#else // DUE:116kHz

  #define writeMOSI_H digitalWrite(mosi_pin, HIGH)

  #define writeMOSI_L digitalWrite(mosi_pin, LOW)

  #define writeSCK_H digitalWrite(sck_pin, HIGH)

  #define writeSCK_L digitalWrite(sck_pin, LOW)

  #define readMISO digitalRead(miso_pin)

#endif