aboutsummaryrefslogtreecommitdiffstats
path: root/machxo2/cells.cc
blob: 21c233d0468f395cc6a52504fc987ae904bb612b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
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")] = 4;
        new_cell->params[ctx->id("INIT")] = 0;
        new_cell->params[ctx->id("FF_USED")] = 0;

        for (int i = 0; i < 4; 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 <= 4);

    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