From 89868b493be48969ffa5d2c0a2625a5aa3cabdcf Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Thu, 4 Apr 2019 08:29:53 +0100 Subject: [PATCH] use ObjectProxy in get_op --- src/add/fadd_state.py | 8 ++++++-- src/add/fpbase.py | 31 +++++++++++++++++++++++++------ 2 files changed, 31 insertions(+), 8 deletions(-) diff --git a/src/add/fadd_state.py b/src/add/fadd_state.py index 343f13ed..79a8723d 100644 --- a/src/add/fadd_state.py +++ b/src/add/fadd_state.py @@ -7,6 +7,8 @@ from nmigen.cli import main, verilog from fpbase import FPNumIn, FPNumOut, FPOp, Overflow, FPBase +from singlepipe import eq + class FPADD(FPBase): @@ -49,13 +51,15 @@ class FPADD(FPBase): # gets operand a with m.State("get_a"): - self.get_op(m, self.in_a, a, "get_b") + res = self.get_op(m, self.in_a, a, "get_b") + m.d.sync += eq([a, self.in_a.ack], res) # ****** # gets operand b with m.State("get_b"): - self.get_op(m, self.in_b, b, "special_cases") + res = self.get_op(m, self.in_b, b, "special_cases") + m.d.sync += eq([b, self.in_b.ack], res) # ****** # special cases: NaNs, infs, zeros, denormalised diff --git a/src/add/fpbase.py b/src/add/fpbase.py index dc2c9020..b15c21ca 100644 --- a/src/add/fpbase.py +++ b/src/add/fpbase.py @@ -7,6 +7,9 @@ from math import log from operator import or_ from functools import reduce +from pipeline import ObjectProxy + + class MultiShiftR: def __init__(self, width): @@ -353,6 +356,22 @@ class FPNumIn(FPNumBase): self.latch_in = Signal() self.op = op + def decode2(self, m): + """ decodes a latched value into sign / exponent / mantissa + + bias is subtracted here, from the exponent. exponent + is extended to 10 bits so that subtract 127 is done on + a 10-bit number + """ + v = self.v + args = [0] * self.m_extra + [v[0:self.e_start]] # pad with extra zeros + #print ("decode", self.e_end) + res = ObjectProxy(m, pipemode=False) + res.m = Cat(*args) # mantissa + res.e = v[self.e_start:self.e_end] - self.P127 # exp + res.s = v[-1] # sign + return res + def decode(self, v): """ decodes a latched value into sign / exponent / mantissa @@ -509,15 +528,15 @@ class FPBase: when both stb and ack are 1. acknowledgement is sent by setting ack to ZERO. """ + res = v.decode2(m) + ack = Signal() with m.If((op.ack) & (op.stb)): m.next = next_state - m.d.sync += [ - # op is latched in from FPNumIn class on same ack/stb - v.decode(op.v), - op.ack.eq(0) - ] + # op is latched in from FPNumIn class on same ack/stb + m.d.comb += ack.eq(0) with m.Else(): - m.d.sync += op.ack.eq(1) + m.d.comb += ack.eq(1) + return [res, ack] def denormalise(self, m, a): """ denormalises a number. this is probably the wrong name for -- 2.30.2