From b6569df02f7a8b0ed86d9f92e8ad28ea2be072a4 Mon Sep 17 00:00:00 2001 From: Robert Jordens Date: Wed, 21 Jun 2017 12:37:11 +0200 Subject: [PATCH] dsp/tools: clean up SatAddMixin logic --- artiq/gateware/dsp/tools.py | 15 +++++++++------ 1 file changed, 9 insertions(+), 6 deletions(-) diff --git a/artiq/gateware/dsp/tools.py b/artiq/gateware/dsp/tools.py index b413fae3f..5edf9aeb5 100644 --- a/artiq/gateware/dsp/tools.py +++ b/artiq/gateware/dsp/tools.py @@ -37,9 +37,8 @@ class SatAddMixin: carry = log2_int(len(a), need_pow2=False) full = Signal((length + carry, True)) limited = Signal((length, True)) - clip = Signal(2) - if clipped is not None: - clipped.eq(clip) + if clipped is None: + clipped = Signal(2) self.comb += [ full.eq(reduce(add, a)), ] @@ -47,15 +46,19 @@ class SatAddMixin: self.comb += [ If(full[-1-carry:] == Replicate(full[-1], carry + 1), limited.eq(full), - clip.eq(0), + clipped.eq(0), ).Else( limited.eq(Cat(Replicate(~full[-1], length - 1), full[-1])), - clip.eq(Cat(full[-1], ~full[-1])), + clipped.eq(Cat(full[-1], ~full[-1])), ) ] else: self.comb += [ clip.eq(Cat(full < limits[0], full > limits[1])), - limited.eq(Array([full, limits[0], limits[1], 0])[clip]), + Case(clip, { + 0b01, limited.eq(limits[0]), + 0b10, limited.eq(limits[1]), + "default": limited.eq(full), + }) ] return limited