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ice40: Only create padin gbuf for PLLs if global output actually used

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Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
This commit is contained in:
Sylvain Munaut 2019-04-17 06:51:11 +02:00
parent 9dd68aa0e2
commit 6387a3d33e
1 changed files with 38 additions and 11 deletions
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49
ice40/pack.cc
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@ -868,16 +868,26 @@ static void place_plls(Context *ctx)
BelId gb_bel = ctx->getBelByName(ctx->id(gb_ci->attrs[ctx->id("BEL")]));
for (auto placed_pll : pll_used_bels) {
CellInfo *ci = placed_pll.second;
// Used global connections
bool gb_a_used = ci->ports.count(id_PLLOUT_A_GLOBAL) && (ci->ports[id_PLLOUT_A_GLOBAL].net != nullptr) &&
(ci->ports[id_PLLOUT_A_GLOBAL].net->users.size() > 0);
bool gb_b_used = is_sb_pll40_dual(ctx, ci) && ci->ports.count(id_PLLOUT_B_GLOBAL) &&
(ci->ports[id_PLLOUT_B_GLOBAL].net != nullptr) &&
(ci->ports[id_PLLOUT_B_GLOBAL].net->users.size() > 0);
// Check for conflict
BelPin pll_io_a, pll_io_b;
BelId gb_a, gb_b;
std::tie(pll_io_a, gb_a, pll_io_b, gb_b) = pll_all_bels[placed_pll.first];
if (gb_bel == gb_a) {
if (gb_a_used && (gb_bel == gb_a)) {
log_error("PLL '%s' A output conflict with SB_GB '%s'\n", placed_pll.second->name.c_str(ctx),
gb_cell.second->name.c_str(ctx));
} else if (gb_bel == gb_b) {
if (is_sb_pll40_dual(ctx, placed_pll.second))
log_error("PLL '%s' B output conflicts with SB_GB '%s'\n", placed_pll.second->name.c_str(ctx),
gb_cell.second->name.c_str(ctx));
}
if (gb_b_used && (gb_bel == gb_b)) {
log_error("PLL '%s' B output conflicts with SB_GB '%s'\n", placed_pll.second->name.c_str(ctx),
gb_cell.second->name.c_str(ctx));
}
}
@ -903,6 +913,13 @@ static void place_plls(Context *ctx)
log_error("PLL '%s' is of CORE type but doesn't have a valid REFERENCECLK connection\n",
ci->name.c_str(ctx));
// Used global connections
bool gb_a_used = ci->ports.count(id_PLLOUT_A_GLOBAL) && (ci->ports[id_PLLOUT_A_GLOBAL].net != nullptr) &&
(ci->ports[id_PLLOUT_A_GLOBAL].net->users.size() > 0);
bool gb_b_used = is_sb_pll40_dual(ctx, ci) && ci->ports.count(id_PLLOUT_B_GLOBAL) &&
(ci->ports[id_PLLOUT_B_GLOBAL].net != nullptr) &&
(ci->ports[id_PLLOUT_B_GLOBAL].net->users.size() > 0);
// Could this be a PAD PLL ?
bool could_be_pad = false;
BelId pad_bel;
@ -924,9 +941,9 @@ static void place_plls(Context *ctx)
}
if (bel2io.count(pll_io_b.bel) && is_sb_pll40_dual(ctx, ci))
continue;
if (bel2gb.count(gb_a))
if (gb_a_used && bel2gb.count(gb_a))
continue;
if (bel2gb.count(gb_b) && is_sb_pll40_dual(ctx, ci))
if (gb_b_used && bel2gb.count(gb_b))
continue;
found_bel = bel_pll.first;
break;
@ -1337,10 +1354,20 @@ static void pack_special(Context *ctx)
else
continue;
std::unique_ptr<CellInfo> gb =
create_padin_gbuf(ctx, packed.get(), pi.name,
"$gbuf_" + ci->name.str(ctx) + "_pllout_" + (is_b_port ? "b" : "a"));
new_cells.push_back(std::move(gb));
// Only if there is actually a net ...
if (pi.net != nullptr) {
// ... and it's used
if (pi.net->users.size() > 0) {
std::unique_ptr<CellInfo> gb =
create_padin_gbuf(ctx, packed.get(), pi.name,
"$gbuf_" + ci->name.str(ctx) + "_pllout_" + (is_b_port ? "b" : "a"));
new_cells.push_back(std::move(gb));
} else {
// If not, remove it to avoid routing issues
ctx->nets.erase(pi.net->name);
packed->ports[pi.name].net = nullptr;
}
}
}
new_cells.push_back(std::move(packed));