Delphi CRC校验

/// <summary>
/// CRC校验
/// </summary>
/// <param name='data'>数据</param>
/// <returns>校验和</returns>
function CRC16(data: TBytes): TBytes;

var
    CRC16Lo, CRC16Hi: Byte; // //CRC寄存器
    CL, CH: Byte; // //多项式码0xA001
    SaveHi, SaveLo: Byte;
    Flag: Int16;
    i: Integer;
    returnData: TBytes;
begin
    CRC16Lo := $FF;
    CRC16Hi := $FF;
    CL := $1;
    CH := $A0;

    for i := 0 to High(data) - 2 do
    begin
        CRC16Lo := Byte(CRC16Lo xor data[i]); // 每一个数据与CRC寄存器进行异或
        for Flag := 0 to 7 do
        begin
            SaveHi := CRC16Hi;
            SaveLo := CRC16Lo;

            CRC16Hi := Byte(CRC16Hi shr 1); // 高位右移一位
            CRC16Lo := Byte(CRC16Lo shr 1); // 低位右移一位