<agg>
is there any easy way to check for overflow with signed arithmetic? with unsigned i'd just make a one-wider signal and check the top bit but that seems trickier with signed
<agg>
(I guess cast inputs to unsigned and then add is probably the way...)
<mwk>
for signed C = A + B, overflow happened iff sign(A) == sign(B) && sign(A) != sign(C)
<agg>
oh, so just a separate circuit on the side to make an overflow bit? that's nice, thanks
<mwk>
and that's the usual formula used to implement sign flags in ALUs, etc
<_whitenotifier-a>
[YoWASP/nextpnr] whitequark pushed 1 commit to develop [+0/-0/±1] https://git.io/JleHg
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<agg>
whitequark: should yowasp-yosys export yowasp-yosys-config? it looks like the cxxrtl.h header is in yowasp-yosys but I can't figure out how to locate it
<whitequark>
it should but currently doesn't
<whitequark>
essentially, yosys-config needs to be rewritten for yowasp
<agg>
ah, should have known it wouldn't be that simple
<agg>
DX-MON: your pins has pin 6 appearing twice, is that deliberate?
<agg>
"1 3 6 7 2 4 *6* 8"
<DX-MON>
it is not.. thank you
<DX-MON>
the first 6 should be a 5
<DX-MON>
ohey, now it builds
<DX-MON>
wrong word.. it synthesises except for a known set of driver conflicts that are currently deliberate but which when I do proper memory region decoding on the peripheral bus will get solved
<cr19011>
"It it closer to working as intended than before"
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<DX-MON>
yeah, p.much
<DX-MON>
been working on formalising the SoC I built so I can more flexibly change it and write new periphals.. which means doing busses properly
<DX-MON>
figured I'd write a GPIO peripheral which is why the whole poking connectors and PMODs happened