diff options
| author | Sylvain Munaut <tnt@246tNt.com> | 2023-01-29 22:04:13 +0100 |
|---|---|---|
| committer | Sylvain Munaut <tnt@246tNt.com> | 2023-01-29 22:35:19 +0100 |
| commit | f50d4c1ed13142471505e0233e7985052d868ac2 (patch) | |
| tree | deaf661d7c07a89534ed3f817714925a6a32bd44 /ice40 | |
| parent | 0cf5006e3bbad476616f09bf1baf8a2953e1c616 (diff) | |
| download | nextpnr-f50d4c1ed13142471505e0233e7985052d868ac2.tar.gz nextpnr-f50d4c1ed13142471505e0233e7985052d868ac2.tar.bz2 nextpnr-f50d4c1ed13142471505e0233e7985052d868ac2.zip | |
ice40: Support for undriven / unconnected output ports
If a port specified as output (and thus had a $nextpnr_obuf inserted)
is undriven (const `z` or const `x`), we make sure to not enable
the output driver. Also enable pull-ups if it was requested by the user.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Diffstat (limited to 'ice40')
| -rw-r--r-- | ice40/cells.cc | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/ice40/cells.cc b/ice40/cells.cc index 5e3bd139..10964f3c 100644 --- a/ice40/cells.cc +++ b/ice40/cells.cc @@ -411,7 +411,12 @@ void nxio_to_sb(Context *ctx, CellInfo *nxio, CellInfo *sbio, pool<IdString> &to nxio->movePortTo(id_O, sbio, id_D_IN_0); pull_up_attr = true; } else if (nxio->type == ctx->id("$nextpnr_obuf")) { - sbio->params[id_PIN_TYPE] = 25; + NetInfo *i = nxio->getPort(id_I); + if (i == nullptr || i->driver.cell == nullptr) { + sbio->params[id_PIN_TYPE] = 1; + pull_up_attr = true; + } else + sbio->params[id_PIN_TYPE] = 25; nxio->movePortTo(id_I, sbio, id_D_OUT_0); } else if (nxio->type == ctx->id("$nextpnr_iobuf")) { // N.B. tristate will be dealt with below |