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| author | Maciej Kurc <mkurc@antmicro.com> | 2022-03-15 12:35:10 +0100 |
|---|---|---|
| committer | Maciej Kurc <mkurc@antmicro.com> | 2022-03-16 09:20:15 +0100 |
| commit | 237391c1b8047d248dc5aa27c7d78edeb86f61e9 (patch) | |
| tree | 04a63ab197608a36494e1679059ae47f32723aa8 /nexus | |
| parent | 43861c0ee298c4d2a5cc89a42e816299c7f86138 (diff) | |
| download | nextpnr-237391c1b8047d248dc5aa27c7d78edeb86f61e9.tar.gz nextpnr-237391c1b8047d248dc5aa27c7d78edeb86f61e9.tar.bz2 nextpnr-237391c1b8047d248dc5aa27c7d78edeb86f61e9.zip | |
nexus: Corrected auto frequency constraint for LF output of OSCA
Signed-off-by: Maciej Kurc <mkurc@antmicro.com>
Diffstat (limited to 'nexus')
| -rw-r--r-- | nexus/pack.cc | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/nexus/pack.cc b/nexus/pack.cc index cc86699a..bb62ec85 100644 --- a/nexus/pack.cc +++ b/nexus/pack.cc @@ -2000,7 +2000,7 @@ struct NexusPacker copy_constraint(ci, id_CLKI, id_CLKO, 1); } else if (ci->type == id_DCS) { // For DCC copy the worst case ("fastest") constraint - delay_t period_clk0, period_clk1; + delay_t period_clk0 = 0, period_clk1 = 0; bool have_clk0 = get_period(ci, id_CLK0, period_clk0); bool have_clk1 = get_period(ci, id_CLK1, period_clk1); if (have_clk0 && !have_clk1) { @@ -2014,7 +2014,7 @@ struct NexusPacker int div = int_or_default(ci->params, id_HF_CLK_DIV, 128); const float tol = 1.07f; // OSCA has +/-7% frequency tolerance, assume the worst case. set_period(ci, id_HFCLKOUT, delay_t((1.0e6 / 450) * (div + 1) / tol)); - set_period(ci, id_LFCLKOUT, delay_t((1.0e3 / 10) / tol)); + set_period(ci, id_LFCLKOUT, delay_t((1.0e9 / 32) / tol)); } else if (ci->type == id_PLL_CORE) { static const std::array<IdString, 6> div{id_DIVA, id_DIVB, id_DIVC, id_DIVD, id_DIVE, id_DIVF}; static const std::array<IdString, 6> output{id_CLKOP, id_CLKOS, id_CLKOS2, |