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timing: Fix Fmax for clocks with mixed edge usage

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Signed-off-by: David Shah <dave@ds0.me>
This commit is contained in:
David Shah 2018-11-04 14:26:16 +00:00
parent 07e265868b
commit bd2b3e5e02
1 changed files with 11 additions and 10 deletions
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21
common/timing.cc
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@ -517,6 +517,7 @@ void timing_analysis(Context *ctx, bool print_histogram, bool print_fmax, bool p
print_histogram ? &slack_histogram : nullptr);
auto min_slack = timing.walk_paths();
std::map<IdString, std::pair<ClockPair, CriticalPath>> clock_reports;
std::map<IdString, double> clock_fmax;
std::vector<ClockPair> xclock_paths;
if (print_path || print_fmax) {
for (auto path : crit_paths) {
@ -524,10 +525,15 @@ void timing_analysis(Context *ctx, bool print_histogram, bool print_fmax, bool p
const ClockEvent &b = path.first.end;
if (a.clock != b.clock || a.clock == ctx->id("$async$"))
continue;
delay_t slack = path.second.path_period - path.second.path_delay;
if (!clock_reports.count(a.clock) ||
slack < (clock_reports.at(a.clock).second.path_period - clock_reports.at(a.clock).second.path_delay)) {
double Fmax;
if (a.edge == b.edge)
Fmax = 1000 / ctx->getDelayNS(path.second.path_delay);
else
Fmax = 500 / ctx->getDelayNS(path.second.path_delay);
if (!clock_fmax.count(a.clock) ||
Fmax < clock_fmax.at(a.clock)) {
clock_reports[a.clock] = path;
clock_fmax[a.clock] = Fmax;
}
}
@ -578,6 +584,7 @@ void timing_analysis(Context *ctx, bool print_histogram, bool print_fmax, bool p
const NetInfo *clknet = get_net_or_empty(front_driver.cell, clockInfo.clock_port);
if (clknet != nullptr && clknet->name == clocks.start.clock &&
clockInfo.edge == clocks.start.edge) {
last_port = clockInfo.clock_port;
}
}
}
@ -631,13 +638,7 @@ void timing_analysis(Context *ctx, bool print_histogram, bool print_fmax, bool p
if (print_fmax) {
log_break();
for (auto &clock : clock_reports) {
double Fmax;
if (clock.second.first.start.edge == clock.second.first.end.edge)
Fmax = 1000 / ctx->getDelayNS(clock.second.second.path_delay);
else
Fmax = 500 / ctx->getDelayNS(clock.second.second.path_delay);
log_info("Max frequency for clock '%s': %.02f MHz\n", clock.first.c_str(ctx), Fmax);
log_info("Max frequency for clock '%s': %.02f MHz\n", clock.first.c_str(ctx), clock_fmax[clock.first]);
}
log_break();