PioClock.hpp

[詳解]

//
//    raspberry pi pico PIO clock
//
//    Copyright (c) 2022 udonrobo
//
 
#pragma once
 
#if defined(ARDUINO_ARCH_RP2040)
 
#    include "SquareWave.pio.hpp"
#    include "StateMachineAllocator.hpp"
 
namespace Udon
{

    inline bool PioClockBegin(uint8_t pin, uint32_t clockSpeed)
    {
        auto sm = Pio::AllocateStateMachine(Udon::Pio::Sqwave::squarewave_program);
        if (not sm)
        {
            return false;
        }
 
        for (unsigned int i = 0; i < count_of(Pio::Sqwave::squarewave_program_instructions); i++)
            sm->pio->instr_mem[i] = Pio::Sqwave::squarewave_program_instructions[i];
 
        sm->pio->sm[sm->index].clkdiv = (uint32_t)(F_CPU * 0.25f * (1 << 16) / clockSpeed);    // 周波数設定(周波数低めのほうが誤差が少ない)
 
        sm->pio->sm[sm->index].pinctrl = (1 << PIO_SM0_PINCTRL_SET_COUNT_LSB) | (pin << PIO_SM0_PINCTRL_SET_BASE_LSB);    // PIOがIOピンにアクセスできるようにする
 
        gpio_set_function(pin, sm->pio == pio0 ? GPIO_FUNC_PIO0 : GPIO_FUNC_PIO1);
 
        // pio_sm_init(pio, sm, offset, &c);
        pio_sm_set_enabled(sm->pio, sm->index, true);
 
        return true;
    }
 
}    // namespace Udon
 
#endif