se050_crc.hpp

Go to the documentation of this file.

 
#pragma once
 
#include <cstddef>
#include <cstdint>
 
namespace se050::crc {
 
[[nodiscard]] inline std::uint16_t Crc16Edc7816(const std::uint8_t* buffer, std::size_t offset,
                                                std::size_t length) noexcept {
    std::uint16_t crc = 0xFFFFU;
    for (std::size_t i = offset; i < offset + length; ++i) {
        crc ^= static_cast<std::uint16_t>(buffer[i]);
        for (int bit = 8; bit > 0; --bit) {
            if ((crc & 0x0001U) != 0U) {
                crc = static_cast<std::uint16_t>((crc >> 1) ^ 0x8408U);
            } else {
                crc = static_cast<std::uint16_t>(crc >> 1);
            }
        }
    }
    crc = static_cast<std::uint16_t>(crc ^ 0xFFFFU);
    return crc;
}
 
inline void AppendEdc(std::uint8_t* frame, std::size_t len_without_edc) noexcept {
    const std::uint16_t c = Crc16Edc7816(frame, 0, len_without_edc);
    frame[len_without_edc] = static_cast<std::uint8_t>(c & 0xFFU);
    frame[len_without_edc + 1U] = static_cast<std::uint8_t>((c >> 8) & 0xFFU);
}
 
[[nodiscard]] inline bool VerifyFrameCrc(const std::uint8_t* frame, std::size_t total_len) noexcept {
    if (total_len < 5U) {
        return false;
    }
    const std::uint16_t recv =
        static_cast<std::uint16_t>(static_cast<std::uint16_t>(frame[total_len - 1U]) << 8 |
                                    frame[total_len - 2U]);
    const std::uint16_t calc = Crc16Edc7816(frame, 0, total_len - 2U);
    return recv == calc;
}
 
}  // namespace se050::crc