基于vivado Verilog的伪随机数发生器，采用LFSR算法，并对其进行了升级，使用反馈级联的思想，从最大周期为2^n提升为原来的3-5倍(Based on vivado Verilog pseudo random number generator, using LFSR algorithm, and upgrade it, using the idea of feedback cascade, from the maximum cycle of 2^n to 3-5 times the