You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
52 lines
1.5 KiB
Python
52 lines
1.5 KiB
Python
from amaranth import *
|
|
|
|
from power_fv import pfv
|
|
from power_fv.insn.const import *
|
|
|
|
from . import InsnSpec
|
|
from .utils import iea, byte_reversed
|
|
|
|
|
|
__all__ = ["ByteReverseSpec"]
|
|
|
|
|
|
class ByteReverseSpec(InsnSpec, Elaboratable):
|
|
def __init__(self, insn):
|
|
self.pfv = pfv.Interface()
|
|
self.insn = insn
|
|
|
|
def elaborate(self, platform):
|
|
m = Module()
|
|
|
|
m.d.comb += [
|
|
self.pfv.stb .eq(1),
|
|
self.pfv.insn.eq(Cat(Const(0, 32), self.insn.as_value())),
|
|
self.pfv.intr.eq(0),
|
|
self.pfv.nia .eq(iea(self.pfv.cia + 4, self.pfv.msr.r_data.sf)),
|
|
self.pfv.msr.r_mask.sf.eq(1),
|
|
]
|
|
|
|
m.d.comb += [
|
|
self.pfv.rs.index.eq(self.insn.RS),
|
|
self.pfv.rs.r_stb.eq(1),
|
|
self.pfv.ra.index.eq(self.insn.RA),
|
|
self.pfv.ra.w_stb.eq(1),
|
|
]
|
|
|
|
if isinstance(self.insn, BRH):
|
|
for i in range(64//16):
|
|
rs_hword = self.pfv.rs.r_data.word_select(i, width=16)
|
|
ra_hword = self.pfv.ra.w_data.word_select(i, width=16)
|
|
m.d.comb += ra_hword.eq(byte_reversed(rs_hword, en=1))
|
|
|
|
elif isinstance(self.insn, BRW):
|
|
for i in range(64//32):
|
|
rs_word = self.pfv.rs.r_data.word_select(i, width=32)
|
|
ra_word = self.pfv.ra.w_data.word_select(i, width=32)
|
|
m.d.comb += ra_word.eq(byte_reversed(rs_word, en=1))
|
|
|
|
else:
|
|
assert False
|
|
|
|
return m
|