diff options
Diffstat (limited to 'ice40')
-rw-r--r-- | ice40/cells.cc | 13 | ||||
-rw-r--r-- | ice40/cells.h | 5 | ||||
-rw-r--r-- | ice40/pack.cc | 79 | ||||
-rw-r--r-- | ice40/pack.h | 27 |
4 files changed, 124 insertions, 0 deletions
diff --git a/ice40/cells.cc b/ice40/cells.cc index 328b5f2d..db13a55f 100644 --- a/ice40/cells.cc +++ b/ice40/cells.cc @@ -64,6 +64,19 @@ CellInfo *create_ice_cell(Design *design, IdString type, IdString name) return new_cell; } +void lut_to_lc(CellInfo *lut, CellInfo *lc, bool no_dff) +{ + lc->params["LUT_INIT"] = lut->params["LUT_INIT"]; + replace_port(lut, "I0", lc, "I0"); + replace_port(lut, "I1", lc, "I1"); + replace_port(lut, "I2", lc, "I2"); + replace_port(lut, "I3", lc, "I3"); + if (no_dff) { + replace_port(lut, "O", lc, "O"); + lc->params["DFF_ENABLE"] = "0"; + } +} + void dff_to_lc(CellInfo *dff, CellInfo *lc, bool pass_thru_lut) { lc->params["DFF_ENABLE"] = "1"; diff --git a/ice40/cells.h b/ice40/cells.h index 1fa85413..a2d45df6 100644 --- a/ice40/cells.h +++ b/ice40/cells.h @@ -45,6 +45,11 @@ inline bool is_ff(const CellInfo *cell) cell->type == "SB_DFFNESS" || cell->type == "SB_DFFNES"; } +// Convert a SB_LUT primitive to (part of) an ICESTORM_LC, swapping ports +// as needed. Set no_dff if a DFF is not being used, so that the output +// can be reconnected +void lut_to_lc(CellInfo *lut, CellInfo *lc, bool no_dff = true); + // Convert a SB_DFFx primitive to (part of) an ICESTORM_LC, setting parameters // and reconnecting signals as necessary. If pass_thru_lut is True, the LUT will // be configured as pass through and D connected to I0, otherwise D will be diff --git a/ice40/pack.cc b/ice40/pack.cc new file mode 100644 index 00000000..692bfba2 --- /dev/null +++ b/ice40/pack.cc @@ -0,0 +1,79 @@ +/* + * nextpnr -- Next Generation Place and Route + * + * Copyright (C) 2018 Clifford Wolf <clifford@clifford.at> + * Copyright (C) 2018 David Shah <dave@ds0.me> + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + */ + +#include "pack.h" +#include "cells.h" +#include "design_utils.h" +#include "log.h" + +#include <unordered_set> + +// Pack LUTs and LUT-FF pairs +static void pack_lut_lutffs(Design *design) +{ + std::unordered_set<IdString> packed_cells; + for (auto cell : design->cells) { + CellInfo *ci = cell.second; + if (is_lut(ci)) { + CellInfo *packed = create_ice_cell(design, "ICESTORM_LC", + std::string(ci->name) + "_LC"); + packed_cells.insert(ci->name); + // See if we can pack into a DFF + // TODO: LUT cascade + NetInfo *o = ci->ports.at("O").net; + CellInfo *dff = net_only_drives(o, is_ff, "D", true); + if (dff) { + lut_to_lc(ci, packed, false); + dff_to_lc(dff, packed, false); + packed_cells.insert(dff->name); + } else { + lut_to_lc(ci, packed, true); + } + } + } + for (auto pcell : packed_cells) { + design->cells.erase(pcell); + } +} + +// Pack FFs not packed as LUTFFs +static void pack_nonlut_ffs(Design *design) +{ + std::unordered_set<IdString> packed_cells; + for (auto cell : design->cells) { + CellInfo *ci = cell.second; + if (is_ff(ci)) { + CellInfo *packed = create_ice_cell(design, "ICESTORM_LC", + std::string(ci->name) + "_LC"); + packed_cells.insert(ci->name); + dff_to_lc(ci, packed, true); + } + } + for (auto pcell : packed_cells) { + design->cells.erase(pcell); + } +} + +// Main pack function +void pack_design(Design *design) +{ + pack_lut_lutffs(design); + pack_nonlut_ffs(design); +} diff --git a/ice40/pack.h b/ice40/pack.h new file mode 100644 index 00000000..87a390ff --- /dev/null +++ b/ice40/pack.h @@ -0,0 +1,27 @@ +/* + * nextpnr -- Next Generation Place and Route + * + * Copyright (C) 2018 Clifford Wolf <clifford@clifford.at> + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + */ + +#ifndef PACK_H +#define PACK_H + +#include "nextpnr.h" + +void pack_design(Design *design); + +#endif // ROUTE_H |