sdc-plugin/buffers.h

/*
 *  yosys -- Yosys Open SYnthesis Suite
 *
 *  Copyright (C) 2020  The Symbiflow Authors
 *
 *  Permission to use, copy, modify, and/or distribute this software for any
 *  purpose with or without fee is hereby granted, provided that the above
 *  copyright notice and this permission notice appear in all copies.
 *
 *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */
#ifndef _BUFFERS_H_
#define _BUFFERS_H_

#include <string>
#include <unordered_map>
#include <vector>
#include "kernel/rtlil.h"

USING_YOSYS_NAMESPACE

struct Buffer {
    Buffer(float delay, const std::string& name, const std::string& output)
        : delay(delay), name(name), output(output) {}
    float delay;
    std::string name;
    std::string output;
};

struct IBuf : Buffer {
    IBuf() : Buffer(0, "IBUF", "O"){};
};

struct Bufg : Buffer {
    Bufg() : Buffer(0, "BUFG", "O"){};
};

struct Pll {
    Pll(RTLIL::Cell* cell, float input_clock_period, float input_clock_rising_edge);

    // Helper function to fetch a cell parameter or return a default value
    static float FetchParam(RTLIL::Cell* cell, std::string&& param_name,
                            float default_value);

    // Get the period of the input clock
    // TODO Add support for CLKINSEL
    float ClkinPeriod() { return clkin1_period; }

    static const std::vector<std::string> inputs;
    static const std::vector<std::string> outputs;
    std::unordered_map<std::string, float> clkout_period;
    std::unordered_map<std::string, float> clkout_duty_cycle;
    std::unordered_map<std::string, float> clkout_rising_edge;
    std::unordered_map<std::string, float> clkout_falling_edge;

   private:
    // Approximate equality check of the input clock period and specified in
    // CLKIN[1/2]_PERIOD parameter
    void CheckInputClockPeriod(RTLIL::Cell* cell, float input_clock_period);

    // Fetch cell's parameters needed for further calculations
    void FetchParams(RTLIL::Cell* cell);

    // Calculate the period on the output clocks
    void CalculateOutputClockPeriods();

    // Calculate the rising and falling edges of the output clocks
    void CalculateOutputClockWaveforms(float input_clock_rising_edge);

    static const float delay;
    static const std::string name;
    std::unordered_map<std::string, float> clkout_divisor;
    std::unordered_map<std::string, float> clkout_phase;
    float clkin1_period;
    float clkin2_period;
    float divclk_divisor;
    float clk_mult;
    float clk_fbout_phase;
};

#endif  // _BUFFERS_H_