diff options
Diffstat (limited to 'quantum/quantum.h')
| -rw-r--r-- | quantum/quantum.h | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/quantum/quantum.h b/quantum/quantum.h index 83694c8324..d234e6ea0d 100644 --- a/quantum/quantum.h +++ b/quantum/quantum.h @@ -210,6 +210,13 @@ typedef uint8_t pin_t; # define togglePin(pin) (PORTx_ADDRESS(pin) ^= _BV((pin)&0xF)) +/* The AVR series GPIOs have a one clock read delay for changes in the digital input signal. + * But here's more margin to make it two clocks. */ +# if !defined(GPIO_INPUT_PIN_DELAY) +# define GPIO_INPUT_PIN_DELAY 2 +# endif +# define waitInputPinDelay() wait_cpuclock(GPIO_INPUT_PIN_DELAY) + #elif defined(PROTOCOL_CHIBIOS) typedef ioline_t pin_t; @@ -225,6 +232,28 @@ typedef ioline_t pin_t; # define readPin(pin) palReadLine(pin) # define togglePin(pin) palToggleLine(pin) + +#endif + +#if defined(__ARMEL__) || defined(__ARMEB__) +/* For GPIOs on ARM-based MCUs, the input pins are sampled by the clock of the bus + * to which the GPIO is connected. + * The connected buses differ depending on the various series of MCUs. + * And since the instruction execution clock of the CPU and the bus clock of GPIO are different, + * there is a delay of several clocks to read the change of the input signal. + * + * Define this delay with the GPIO_INPUT_PIN_DELAY macro. + * If the GPIO_INPUT_PIN_DELAY macro is not defined, the following default values will be used. + * (A fairly large value of 0.25 microseconds is set.) + */ +# if !defined(GPIO_INPUT_PIN_DELAY) +# if defined(STM32_SYSCLK) +# define GPIO_INPUT_PIN_DELAY (STM32_SYSCLK/1000000L / 4) +# elif defined(KINETIS_SYSCLK_FREQUENCY) +# define GPIO_INPUT_PIN_DELAY (KINETIS_SYSCLK_FREQUENCY/1000000L / 4) +# endif +# endif +# define waitInputPinDelay() wait_cpuclock(GPIO_INPUT_PIN_DELAY) #endif // Atomic macro to help make GPIO and other controls atomic. |