基于VHDL的参数化LFSR模型设计

Design of parameterized LFSR modules based on VHDL

利用VHDL二维数组模型定义LFSR的反馈状态查找表并实现了参数化LFSR反馈回路。对当前状态进行全零模式检测和条件异或运算,结合VHDL条件生成语句实现了参数化Bruijn计数器。定义循环模式计算函数来得到任意位数和模式下的LFSR尾状态,通过状态比较实现了任意循环模式下的参数化LFSR模型。软件综合结果表明,在不同的参数实现下,LFSR模型有优秀的时序性能,能够满足实际应用需要。

The utilization of the feedback state lookup table of VHDL 2-D data structure helps to realize the parameterized LFSR feedback loop. By means of zero state detection and conditional XOR computation, the Bruijn counter could involve the all-zero state in the recursive cycle. After computing the LFSR＇s ending state and comparing it with the current state, the parameterized LFSR module in any cycle mode could be implemented. The results show that LFSR module has a high timing per-formance with different parameters and can meet practical requirements.