设计一个伪随机序列发生器，采用的生成多项式为1+X^3+X^7。要求具有一个RESET端和两个控制端来调整寄存器初值（程序中设定好四种非零初值可选）。-Design a pseudo-random sequence generator, using the generating polynomial 1+ X ^ 3+ X ^ 7. Requires a RESET terminal end and two control registers to adjust the initial value (the program of four non-zero initial value set a good option).