13 8bit configurable galois lfsr

13 : 8bit configurable galois lfsr

How it works

Uses 2 cycles each to set the shift and xor mask registers. It has 3 operation modes: normal shift,

How to test

After reset, set the shift register and xor state, after that normal shift mode


# Input Output
0 clock output[0] lsb normal lfsr output
1 reset output[1] other 7 bits to see the full state
2 mode[0] 00 normal shift mode, 01 set register mode, output[2]
3 mode[1] 10 set mode registers, 11 unused output[3]
4 data_in[0] is used for both filling register and xor mask state output[4]
5 data_in[1] needs 2 cycles to fill all 8 bits output[5]
6 data_in[2] first cyle is lower 4 bits, 2nd upper 4 bits output[6]
7 data_in[3] see above output[7]