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Keep track of bits in variable length chain, to check for taps

This commit is contained in:
Eddie Hung 2019-08-23 16:21:10 -07:00
parent f2d4814284
commit 83e2d87fb8
1 changed files with 12 additions and 0 deletions
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12
passes/pmgen/xilinx_srl.pmg
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@ -186,6 +186,11 @@ state <int> shiftx_width
state <int> slice
udata <int> minlen
udata <vector<pair<Cell*,int>>> chain
udata <pool<SigBit>> chain_bits
code
chain_bits.clear();
endcode
match shiftx
select shiftx->type.in($shiftx)
@ -251,13 +256,20 @@ match next
index <SigBit> port(next, \Q)[idx] === port(shiftx, \A)[shiftx_width-1-GetSize(chain)]
filter port(next, clk_port) == port(first, clk_port)
filter en_port == IdString() || port(next, en_port) == port(first, en_port)
filter !chain_bits.count(port(next, \D)[idx])
set slice idx
endmatch
code
if (next) {
chain_bits.insert(port(next, \Q)[slice]);
chain.emplace_back(next, slice);
if (GetSize(chain) < shiftx_width)
subpattern(tail);
}
finally
if (next) {
chain_bits.erase(port(next, \Q)[slice]);
chain.pop_back();
}
endcode