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ice40: PLace legaliser produces a design that is at least routable for picosoc

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Signed-off-by: David Shah <davey1576@gmail.com>
This commit is contained in:
David Shah 2018-06-28 16:31:52 +02:00
parent 27a9850921
commit 66670831b8
2 changed files with 19 additions and 1 deletions
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1
ice40/bitstream.cc
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@ -178,6 +178,7 @@ void write_asc(const Context *ctx, std::ostream &out)
bool carry_const = get_param_or_def(cell.second.get(), ctx->id("CIN_CONST"));
bool carry_set = get_param_or_def(cell.second.get(), ctx->id("CIN_SET"));
if (carry_const) {
if (!ctx->force)
assert(z == 0);
set_config(ti, config.at(y).at(x), "CarryInSet", carry_set);
}

17
ice40/place_legaliser.cc
View File

@ -155,6 +155,22 @@ class PlacementLegaliser
return i3_next;*/
return (CellInfo *)nullptr;
});
std::unordered_set<IdString> chained;
for (auto &base_chain : carry_chains) {
for (auto c : base_chain.cells)
chained.insert(c->name);
}
// Any cells not in chains, but with carry enabled, must also be put in a single-carry chain
// for correct processing
for (auto cell : sorted(ctx->cells)) {
CellInfo *ci = cell.second;
if (chained.find(cell.first) == chained.end() && is_lc(ctx, ci) && bool_or_default(ci->params, ctx->id("CARRY_ENABLE"))) {
CellChain sChain;
sChain.cells.push_back(ci);
chained.insert(cell.first);
carry_chains.push_back(sChain);
}
}
bool success = true;
// Find midpoints for all chains, before we start tearing them up
std::vector<CellChain> all_chains;
@ -274,6 +290,7 @@ class PlacementLegaliser
CellInfo *passout = make_carry_pass_out(cell->ports.at(ctx->id("COUT")));
chains.back().cells.push_back(passout);
tile.push_back(passout);
start_of_chain = true;
}
}
++curr_cell;