diff options
Diffstat (limited to 'machxo2/cells.cc')
| -rw-r--r-- | machxo2/cells.cc | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/machxo2/cells.cc b/machxo2/cells.cc new file mode 100644 index 00000000..c4421f90 --- /dev/null +++ b/machxo2/cells.cc @@ -0,0 +1,147 @@ +/* + * nextpnr -- Next Generation Place and Route + * + * Copyright (C) 2019 David Shah <david@symbioticeda.com> + * + * 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 "cells.h" +#include "design_utils.h" +#include "log.h" +#include "util.h" + +NEXTPNR_NAMESPACE_BEGIN + +void add_port(const Context *ctx, CellInfo *cell, std::string name, PortType dir) +{ + IdString id = ctx->id(name); + NPNR_ASSERT(cell->ports.count(id) == 0); + cell->ports[id] = PortInfo{id, nullptr, dir}; +} + +std::unique_ptr<CellInfo> create_generic_cell(Context *ctx, IdString type, std::string name) +{ + static int auto_idx = 0; + std::unique_ptr<CellInfo> new_cell = std::unique_ptr<CellInfo>(new CellInfo()); + if (name.empty()) { + new_cell->name = ctx->id("$nextpnr_" + type.str(ctx) + "_" + std::to_string(auto_idx++)); + } else { + new_cell->name = ctx->id(name); + } + new_cell->type = type; + if (type == ctx->id("GENERIC_SLICE")) { + new_cell->params[ctx->id("K")] = ctx->args.K; + new_cell->params[ctx->id("INIT")] = 0; + new_cell->params[ctx->id("FF_USED")] = 0; + + for (int i = 0; i < ctx->args.K; i++) + add_port(ctx, new_cell.get(), "I[" + std::to_string(i) + "]", PORT_IN); + + add_port(ctx, new_cell.get(), "CLK", PORT_IN); + + add_port(ctx, new_cell.get(), "F", PORT_OUT); + add_port(ctx, new_cell.get(), "Q", PORT_OUT); + } else if (type == ctx->id("GENERIC_IOB")) { + new_cell->params[ctx->id("INPUT_USED")] = 0; + new_cell->params[ctx->id("OUTPUT_USED")] = 0; + new_cell->params[ctx->id("ENABLE_USED")] = 0; + + add_port(ctx, new_cell.get(), "PAD", PORT_INOUT); + add_port(ctx, new_cell.get(), "I", PORT_IN); + add_port(ctx, new_cell.get(), "EN", PORT_IN); + add_port(ctx, new_cell.get(), "O", PORT_OUT); + } else { + log_error("unable to create generic cell of type %s", type.c_str(ctx)); + } + return new_cell; +} + +void lut_to_lc(const Context *ctx, CellInfo *lut, CellInfo *lc, bool no_dff) +{ + lc->params[ctx->id("INIT")] = lut->params[ctx->id("INIT")]; + + int lut_k = int_or_default(lut->params, ctx->id("K"), 4); + NPNR_ASSERT(lut_k <= ctx->args.K); + + for (int i = 0; i < lut_k; i++) { + IdString port = ctx->id("I[" + std::to_string(i) + "]"); + replace_port(lut, port, lc, port); + } + + if (no_dff) { + lc->params[ctx->id("FF_USED")] = 0; + replace_port(lut, ctx->id("Q"), lc, ctx->id("F")); + } +} + +void dff_to_lc(const Context *ctx, CellInfo *dff, CellInfo *lc, bool pass_thru_lut) +{ + lc->params[ctx->id("FF_USED")] = 1; + replace_port(dff, ctx->id("CLK"), lc, ctx->id("CLK")); + + if (pass_thru_lut) { + // Fill LUT with alternating 10 + const int init_size = 1 << lc->params[ctx->id("K")].as_int64(); + std::string init; + init.reserve(init_size); + for (int i = 0; i < init_size; i += 2) + init.append("10"); + lc->params[ctx->id("INIT")] = Property::from_string(init); + + replace_port(dff, ctx->id("D"), lc, ctx->id("I[0]")); + } + + replace_port(dff, ctx->id("Q"), lc, ctx->id("Q")); +} + +void nxio_to_iob(Context *ctx, CellInfo *nxio, CellInfo *iob, std::unordered_set<IdString> &todelete_cells) +{ + if (nxio->type == ctx->id("$nextpnr_ibuf")) { + iob->params[ctx->id("INPUT_USED")] = 1; + replace_port(nxio, ctx->id("O"), iob, ctx->id("O")); + } else if (nxio->type == ctx->id("$nextpnr_obuf")) { + iob->params[ctx->id("OUTPUT_USED")] = 1; + replace_port(nxio, ctx->id("I"), iob, ctx->id("I")); + } else if (nxio->type == ctx->id("$nextpnr_iobuf")) { + // N.B. tristate will be dealt with below + iob->params[ctx->id("INPUT_USED")] = 1; + iob->params[ctx->id("OUTPUT_USED")] = 1; + replace_port(nxio, ctx->id("I"), iob, ctx->id("I")); + replace_port(nxio, ctx->id("O"), iob, ctx->id("O")); + } else { + NPNR_ASSERT(false); + } + NetInfo *donet = iob->ports.at(ctx->id("I")).net; + CellInfo *tbuf = net_driven_by( + ctx, donet, [](const Context *ctx, const CellInfo *cell) { return cell->type == ctx->id("$_TBUF_"); }, + ctx->id("Y")); + if (tbuf) { + iob->params[ctx->id("ENABLE_USED")] = 1; + replace_port(tbuf, ctx->id("A"), iob, ctx->id("I")); + replace_port(tbuf, ctx->id("E"), iob, ctx->id("EN")); + + if (donet->users.size() > 1) { + for (auto user : donet->users) + log_info(" remaining tristate user: %s.%s\n", user.cell->name.c_str(ctx), user.port.c_str(ctx)); + log_error("unsupported tristate IO pattern for IO buffer '%s', " + "instantiate GENERIC_IOB manually to ensure correct behaviour\n", + nxio->name.c_str(ctx)); + } + ctx->nets.erase(donet->name); + todelete_cells.insert(tbuf->name); + } +} + +NEXTPNR_NAMESPACE_END |