mayhem-firmware/firmware/common/jtag.hpp

/*
 * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
 *
 * This file is part of PortaPack.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#ifndef __JTAG_H__
#define __JTAG_H__

#include "jtag_target.hpp"

#include <cstdint>
#include <cstddef>

#include <bitset>

namespace jtag {

class JTAG {
   public:
    constexpr JTAG(
        Target& target)
        : target(target) {
    }

    void reset() {
        /* ??? -> Test-Logic-Reset */
        for (size_t i = 0; i < 8; i++) {
            target.clock(1, 0);
        }
    }

    void run_test_idle() {
        /* Test-Logic-Reset -> Run-Test/Idle */
        target.clock(0, 0);
    }

    void runtest_tck(const size_t count) {
        target.delay(count);
    }

    uint32_t shift_ir(const size_t count, const uint32_t value) {
        /* Run-Test/Idle -> Select-DR-Scan -> Select-IR-Scan */
        target.clock(1, 0);
        target.clock(1, 0);
        /* Scan -> Capture -> Shift */
        target.clock(0, 0);
        target.clock(0, 0);

        const auto result = shift(count, value);

        /* Exit1 -> Update */
        target.clock(1, 0);
        /* Update -> Run-Test/Idle */
        target.clock(0, 0);

        return result;
    }

    uint32_t shift_dr(const size_t count, const uint32_t value) {
        /* Run-Test/Idle -> Select-DR-Scan */
        target.clock(1, 0);
        /* Scan -> Capture -> Shift */
        target.clock(0, 0);
        target.clock(0, 0);

        const auto result = shift(count, value);

        /* Exit1 -> Update */
        target.clock(1, 0);
        /* Update -> Run-Test/Idle */
        target.clock(0, 0);

        return result;
    }

   private:
    Target& target;

    uint32_t shift(const size_t count, uint32_t value);
};

} /* namespace jtag */

#endif /*__JTAG_H__*/