sdc-plugin/buffers.h

/*
 * Copyright (C) 2019-2022 The SymbiFlow Authors
 *
 * Use of this source code is governed by a ISC-style
 * license that can be found in the LICENSE file or at
 * https://opensource.org/licenses/ISC
 *
 * SPDX-License-Identifier: ISC
 */
#ifndef _BUFFERS_H_
#define _BUFFERS_H_

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

USING_YOSYS_NAMESPACE

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

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

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

struct ClockDivider {
    std::string type;
};

struct Pll : public ClockDivider {
    Pll() : ClockDivider({"PLLE2_ADV"}) {}
    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_