From a750daabd40ac4fe2054bb88b632ab720d985c4e Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Wed, 21 Aug 2019 05:45:43 +0100 Subject: [PATCH] add new Parts class --- src/ieee754/part_mul_add/multiply.py | 39 ++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+) diff --git a/src/ieee754/part_mul_add/multiply.py b/src/ieee754/part_mul_add/multiply.py index 084f7dde..64994ad3 100644 --- a/src/ieee754/part_mul_add/multiply.py +++ b/src/ieee754/part_mul_add/multiply.py @@ -708,6 +708,45 @@ class LSBNegTerm(Elaboratable): return m +class Parts(Elaboratable): + + def __init__(self, pbwid, epps, n_parts): + self.pbwid = pbwid + # inputs + self.epps = PartitionPoints.like(epps, name="epps") # expanded points + # outputs + self.parts = [Signal(name=f"part_{i}") for i in range(n_parts)] + + def elaborate(self, platform): + m = Module() + + epps, parts = self.epps, self.parts + # collect part-bytes (double factor because the input is extended) + pbs = Signal(self.pbwid, reset_less=True) + tl = [] + for i in range(self.pbwid): + pb = Signal(name="pb%d" % i, reset_less=True) + m.d.comb += pb.eq(epps.part_byte(i, mfactor=2)) # double + tl.append(pb) + m.d.comb += pbs.eq(Cat(*tl)) + + # negated-temporary copy of partition bits + npbs = Signal.like(pbs, reset_less=True) + m.d.comb += npbs.eq(~pbs) + byte_count = 8 // len(parts) + for i in range(len(parts)): + pbl = [] + pbl.append(npbs[i * byte_count - 1]) + for j in range(i * byte_count, (i + 1) * byte_count - 1): + pbl.append(pbs[j]) + pbl.append(npbs[(i + 1) * byte_count - 1]) + value = Signal(len(pbl), name="value_%d" % i, reset_less=True) + m.d.comb += value.eq(Cat(*pbl)) + m.d.comb += parts[i].eq(~(value).bool()) + + return m + + class Part(Elaboratable): """ a key class which, depending on the partitioning, will determine what action to take when parts of the output are signed or unsigned. -- 2.30.2