diff options
author | David Shah <davey1576@gmail.com> | 2018-06-20 15:15:51 +0200 |
---|---|---|
committer | David Shah <davey1576@gmail.com> | 2018-06-20 15:15:51 +0200 |
commit | e45508f6c41273830312a5b88c5e25f266dc67ae (patch) | |
tree | 3cdc327ddeafbfc0d84b62ca42cac08e584da402 | |
parent | 2da90889efb194be4140ebfd5893bdf0ced223f3 (diff) | |
download | nextpnr-e45508f6c41273830312a5b88c5e25f266dc67ae.tar.gz nextpnr-e45508f6c41273830312a5b88c5e25f266dc67ae.tar.bz2 nextpnr-e45508f6c41273830312a5b88c5e25f266dc67ae.zip |
Improving timing annotator
Signed-off-by: David Shah <davey1576@gmail.com>
-rw-r--r-- | common/timing.cc | 18 | ||||
-rw-r--r-- | ice40/main.cc | 2 |
2 files changed, 19 insertions, 1 deletions
diff --git a/common/timing.cc b/common/timing.cc index 5ffd4ea7..a4bda3bb 100644 --- a/common/timing.cc +++ b/common/timing.cc @@ -79,6 +79,14 @@ static delay_t follow_net(Context *ctx, NetInfo *net, int path_length, void assign_budget(Context *ctx, float default_clock) { log_info("Annotating ports with timing budgets\n"); + // Clear delays to a very high value first + delay_t default_slack = delay_t(1.0e12 / default_clock); + for (auto net : ctx->nets) { + for (auto &usr : net.second->users) { + usr.budget = default_slack; + } + } + // Go through all clocked drivers and set up paths for (auto cell : ctx->cells) { for (auto port : cell.second->ports) { if (port.second.type == PORT_OUT) { @@ -93,6 +101,16 @@ void assign_budget(Context *ctx, float default_clock) } } } + // Post-allocation check + for (auto net : ctx->nets) { + for (auto user : net.second->users) { + if (user.budget < 0) + log_warning("port %s.%s, connected to net '%s', has negative " + "timing budget of %fns\n", + user.cell->name.c_str(ctx), user.port.c_str(ctx), + net.first.c_str(ctx), ctx->getDelayNS(user.budget)); + } + } } NEXTPNR_NAMESPACE_END diff --git a/ice40/main.cc b/ice40/main.cc index ea7c9a66..13d8ac0b 100644 --- a/ice40/main.cc +++ b/ice40/main.cc @@ -273,7 +273,7 @@ int main(int argc, char *argv[]) if (!pack_design(&ctx) && !ctx.force) log_error("Packing design failed.\n"); - assign_budget(&ctx); + assign_budget(&ctx, 50e6); print_utilisation(&ctx); if (!vm.count("pack-only")) { |