68 lines
1.7 KiB
Python
68 lines
1.7 KiB
Python
|
from migen.fhdl.std import *
|
||
|
|
from migen.genlib.misc import optree
|
||
|
|
|
||
|
|
@DecorateModule(InsertReset)
|
||
|
|
@DecorateModule(InsertCE)
|
||
|
|
class SATAScrambler(Module):
|
||
|
|
"""SATA Scrambler
|
||
|
|
|
||
|
|
Implement a SATA Scrambler
|
||
|
|
|
||
|
|
Attributes
|
||
|
|
----------
|
||
|
|
value : out
|
||
|
|
Scrambled value.
|
||
|
|
"""
|
||
|
|
def __init__(self):
|
||
|
|
self.value = Signal(32)
|
||
|
|
|
||
|
|
###
|
||
|
|
|
||
|
|
context = Signal(16, reset=0xf0f6)
|
||
|
|
next_value = Signal(32)
|
||
|
|
self.sync += context.eq(next_value[16:32])
|
||
|
|
|
||
|
|
# from SATA specification, if possible replace it
|
||
|
|
# with a generic implementation using polynoms.
|
||
|
|
lfsr_coefs = (
|
||
|
|
(15, 13, 4, 0), #0
|
||
|
|
(15, 14, 13, 5, 4, 1, 0),
|
||
|
|
(14, 13, 6, 5, 4, 2,1, 0),
|
||
|
|
(15, 14, 7, 6, 5, 3,2, 1),
|
||
|
|
(13, 8, 7, 6, 3, 2, 0),
|
||
|
|
(14, 9, 8, 7, 4, 3, 1),
|
||
|
|
(15, 10, 9, 8, 5, 4, 2),
|
||
|
|
(15, 13, 11, 10, 9, 6, 5, 4, 3, 0),
|
||
|
|
(15, 14, 13, 12, 11, 10,7, 6, 5, 1, 0),
|
||
|
|
(14, 12, 11, 8, 7, 6, 4, 2, 1, 0),
|
||
|
|
(15, 13, 12, 9, 8, 7, 5, 3, 2, 1),
|
||
|
|
(15, 14, 10, 9, 8, 6, 3, 2, 0),
|
||
|
|
(13, 11, 10, 9, 7, 3, 1, 0),
|
||
|
|
(14, 12, 11, 10, 8, 4, 2, 1),
|
||
|
|
(15, 13, 12, 11, 9, 5, 3, 2),
|
||
|
|
(15, 14, 12, 10, 6, 3, 0),
|
||
|
|
|
||
|
|
(11, 7, 1, 0), #16
|
||
|
|
(12, 8, 2, 1),
|
||
|
|
(13, 9, 3, 2),
|
||
|
|
(14, 10, 4, 3),
|
||
|
|
(15, 11, 5, 4),
|
||
|
|
(15, 13, 12, 6, 5, 4, 0),
|
||
|
|
(15, 14, 7, 6, 5, 4, 1, 0),
|
||
|
|
(13, 8, 7, 6, 5, 4, 2, 1, 0),
|
||
|
|
(14, 9, 8,7, 6, 5, 3, 2, 1),
|
||
|
|
(15, 10, 9, 8, 7, 6, 4, 3, 2),
|
||
|
|
(15, 13, 11, 10, 9, 8, 7, 5, 3, 0),
|
||
|
|
(15, 14, 13, 12, 11, 10, 9, 8, 6, 1, 0),
|
||
|
|
(14, 12, 11, 10, 9, 7, 4, 2, 1, 0),
|
||
|
|
(15, 13, 12, 11, 10, 8, 5, 3, 2, 1),
|
||
|
|
(15, 14, 12, 11, 9, 6, 3, 2, 0),
|
||
|
|
(12, 10, 7, 3, 1, 0),
|
||
|
|
)
|
||
|
|
|
||
|
|
for n, coefs in enumerate(lfsr_coefs):
|
||
|
|
eq = [context[i] for i in coefs]
|
||
|
|
self.comb += next_value[n].eq(optree("^", eq))
|
||
|
|
|
||
|
|
self.comb += self.value.eq(next_value)
|