Merge branch 'q3k/pll' into 'master'

ice40: support CORE PLLs

See merge request SymbioticEDA/nextpnr!17

9 files changed, 375 insertions, 14 deletions

diff --git a/ice40/arch.cc b/ice40/arch.cc
index 2270fdc1..1d7e9546 100644
--- a/ice40/arch.cc
+++ b/ice40/arch.cc
@@ -2,6 +2,7 @@
  *  nextpnr -- Next Generation Place and Route
  *
  *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
+ *  Copyright (C) 2018  Serge Bazanski <q3k@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
@@ -314,11 +315,12 @@ WireId Arch::getBelPinWire(BelId bel, PortPin pin) const
     int num_bel_wires = chip_info->bel_data[bel.index].num_bel_wires;
     const BelWirePOD *bel_wires = chip_info->bel_data[bel.index].bel_wires.get();
 
-    for (int i = 0; i < num_bel_wires; i++)
+    for (int i = 0; i < num_bel_wires; i++) {
         if (bel_wires[i].port == pin) {
             ret.index = bel_wires[i].wire_index;
             break;
         }
+    }
 
     return ret;
 }
diff --git a/ice40/arch_place.cc b/ice40/arch_place.cc
index d32ebe98..59e1807d 100644
--- a/ice40/arch_place.cc
+++ b/ice40/arch_place.cc
@@ -3,6 +3,7 @@
  *
  *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
  *  Copyright (C) 2018  David Shah <david@symbioticeda.com>
+ *  Copyright (C) 2018  Serge Bazanski <q3k@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
@@ -107,6 +108,32 @@ bool Arch::isValidBelForCell(CellInfo *cell, BelId bel) const
         bel_cells.push_back(cell);
         return logicCellsCompatible(bel_cells);
     } else if (cell->type == id_sb_io) {
+        // Do not allow placement of input SB_IOs on blocks where there a PLL is outputting to.
+
+        // Find shared PLL by looking for driving bel siblings from D_IN_0
+        // that are a PLL clock output.
+        auto wire = getBelPinWire(bel, PIN_D_IN_0);
+        PortPin pll_bel_pin;
+        BelId pll_bel;
+        for (auto pin : getWireBelPins(wire)) {
+            if (pin.pin == PIN_PLLOUT_A || pin.pin == PIN_PLLOUT_B) {
+                pll_bel = pin.bel;
+                pll_bel_pin = pin.pin;
+                break;
+            }
+        }
+        // Is there a PLL that shares this IO buffer?
+        if (pll_bel.index != -1) {
+            // Is a PLL placed in this PLL bel?
+            if (!checkBelAvail(pll_bel)) {
+                // Is the shared port driving a net?
+                auto pll_cell = getBoundBelCell(pll_bel);
+                auto pi = cells.at(pll_cell)->ports[portPinToId(pll_bel_pin)];
+                if (pi.net != nullptr) {
+                    return false;
+                }
+            }
+        }
         return getBelPackagePin(bel) != "";
     } else if (cell->type == id_sb_gb) {
         NPNR_ASSERT(cell->ports.at(id_glb_buf_out).net != nullptr);
diff --git a/ice40/bitstream.cc b/ice40/bitstream.cc
index 9ac8e857..e9851a83 100644
--- a/ice40/bitstream.cc
+++ b/ice40/bitstream.cc
@@ -3,6 +3,7 @@
  *

  *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>

  *  Copyright (C) 2018  David Shah <david@symbioticeda.com>

+ *  Copyright (C) 2018  Serge Bazanski <q3k@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

@@ -74,14 +75,26 @@ void set_config(const TileInfoPOD &ti, std::vector<std::vector<int8_t>> &tile_cf
         for (int i = 0; i < cfg.num_bits; i++) {

             int8_t &cbit = tile_cfg.at(cfg.bits[i].row).at(cfg.bits[i].col);

             if (cbit && !value)

-                log_error("clearing already set config bit %s", name.c_str());

+                log_error("clearing already set config bit %s\n", name.c_str());

             cbit = value;

         }

     } else {

         int8_t &cbit = tile_cfg.at(cfg.bits[index].row).at(cfg.bits[index].col);

         cbit = value;

         if (cbit && !value)

-            log_error("clearing already set config bit %s[%d]", name.c_str(), index);

+            log_error("clearing already set config bit %s[%d]\n", name.c_str(), index);

+    }

+}

+

+// Set an IE_{EN,REN} logical bit in a tile config. Logical means enabled.

+// On {HX,LP}1K devices these bits are active low, so we need to invert them.

+void set_ie_bit_logical(const Context *ctx, const TileInfoPOD &ti, std::vector<std::vector<int8_t>> &tile_cfg,

+                        const std::string &name, bool value)

+{

+    if (ctx->args.type == ArchArgs::LP1K || ctx->args.type == ArchArgs::HX1K) {

+        set_config(ti, tile_cfg, name, !value);

+    } else {

+        set_config(ti, tile_cfg, name, value);

     }

 }

 

@@ -117,7 +130,7 @@ static const BelConfigPOD &get_ec_config(const ChipInfoPOD *chip, BelId bel)
 typedef std::vector<std::vector<std::vector<std::vector<int8_t>>>> chipconfig_t;

 

 static void set_ec_cbit(chipconfig_t &config, const Context *ctx, const BelConfigPOD &cell_cbits, std::string name,

-                        bool value)

+                        bool value, std::string prefix)

 {

     const ChipInfoPOD *chip = ctx->chip_info;

 

@@ -125,7 +138,7 @@ static void set_ec_cbit(chipconfig_t &config, const Context *ctx, const BelConfi
         const auto &cbit = cell_cbits.entries[i];

         if (cbit.entry_name.get() == name) {

             const auto &ti = chip->bits_info->tiles_nonrouting[tile_at(ctx, cbit.x, cbit.y)];

-            set_config(ti, config.at(cbit.y).at(cbit.x), std::string("IpConfig.") + cbit.cbit_name.get(), value);

+            set_config(ti, config.at(cbit.y).at(cbit.x), prefix + cbit.cbit_name.get(), value);

             return;

         }

     }

@@ -133,7 +146,7 @@ static void set_ec_cbit(chipconfig_t &config, const Context *ctx, const BelConfi
 }

 

 void configure_extra_cell(chipconfig_t &config, const Context *ctx, CellInfo *cell,

-                          const std::vector<std::pair<std::string, int>> &params, bool string_style)

+                          const std::vector<std::pair<std::string, int>> &params, bool string_style, std::string prefix)

 {

     const ChipInfoPOD *chip = ctx->chip_info;

     const auto &bc = get_ec_config(chip, cell->bel);

@@ -163,10 +176,10 @@ void configure_extra_cell(chipconfig_t &config, const Context *ctx, CellInfo *ce
 

         value.resize(p.second);

         if (p.second == 1) {

-            set_ec_cbit(config, ctx, bc, p.first, value.at(0));

+            set_ec_cbit(config, ctx, bc, p.first, value.at(0), prefix);

         } else {

             for (int i = 0; i < p.second; i++) {

-                set_ec_cbit(config, ctx, bc, p.first + "_" + std::to_string(i), value.at(i));

+                set_ec_cbit(config, ctx, bc, p.first + "_" + std::to_string(i), value.at(i), prefix);

             }

         }

     }

@@ -258,8 +271,13 @@ void write_asc(const Context *ctx, std::ostream &out)
             }

         }

     }

+

+    std::unordered_set<Loc> sb_io_used_by_pll;

+    std::unordered_set<Loc> sb_io_used_by_io;

+

     // Set logic cell config

     for (auto &cell : ctx->cells) {

+

         BelId bel = cell.second.get()->bel;

         if (bel == BelId()) {

             std::cout << "Found unplaced cell " << cell.first.str(ctx) << " while generating bitstream!" << std::endl;

@@ -304,6 +322,7 @@ void write_asc(const Context *ctx, std::ostream &out)
         } else if (cell.second->type == ctx->id("SB_IO")) {

             const BelInfoPOD &beli = ci.bel_data[bel.index];

             int x = beli.x, y = beli.y, z = beli.z;

+            sb_io_used_by_io.insert(Loc(x, y, z));

             const TileInfoPOD &ti = bi.tiles_nonrouting[TILE_IO];

             unsigned pin_type = get_param_or_def(cell.second.get(), ctx->id("PIN_TYPE"));

             bool neg_trigger = get_param_or_def(cell.second.get(), ctx->id("NEG_TRIGGER"));

@@ -405,7 +424,70 @@ void write_asc(const Context *ctx, std::ostream &out)
                                                                            {"MODE_8x8", 1},

                                                                            {"A_SIGNED", 1},

                                                                            {"B_SIGNED", 1}};

-            configure_extra_cell(config, ctx, cell.second.get(), mac16_params, false);

+            configure_extra_cell(config, ctx, cell.second.get(), mac16_params, false, std::string("IpConfig."));

+        } else if (cell.second->type == ctx->id("ICESTORM_PLL")) {

+            const std::vector<std::pair<std::string, int>> pll_params = {{"DELAY_ADJMODE_FB", 1},

+                                                                         {"DELAY_ADJMODE_REL", 1},

+                                                                         {"DIVF", 7},

+                                                                         {"DIVQ", 3},

+                                                                         {"DIVR", 4},

+                                                                         {"FDA_FEEDBACK", 4},

+                                                                         {"FDA_RELATIVE", 4},

+                                                                         {"FEEDBACK_PATH", 3},

+                                                                         {"FILTER_RANGE", 3},

+                                                                         {"PLLOUT_SELECT_A", 2},

+                                                                         {"PLLOUT_SELECT_B", 2},

+                                                                         {"PLLTYPE", 3},

+                                                                         {"SHIFTREG_DIV_MODE", 1},

+                                                                         {"TEST_MODE", 1}};

+            configure_extra_cell(config, ctx, cell.second.get(), pll_params, false, std::string("PLL."));

+

+            // Configure the SB_IOs that the clock outputs are going through.

+            for (auto &port : cell.second->ports) {

+                // If this port is not a PLLOUT port, ignore it.

+                if (port.second.name != ctx->id("PLLOUT_A") && port.second.name != ctx->id("PLLOUT_B"))

+                    continue;

+

+                // If the output is not driving any net, ignore it.

+                if (port.second.net == nullptr)

+                    continue;

+

+                // Get IO Bel that this PLL port goes through by finding sibling

+                // Bel driving the same wire via PIN_D_IN_0.

+                auto wire = ctx->getBelPinWire(cell.second->bel, ctx->portPinFromId(port.second.name));

+                BelId io_bel;

+                for (auto pin : ctx->getWireBelPins(wire)) {

+                    if (pin.pin == PIN_D_IN_0) {

+                        io_bel = pin.bel;

+                        break;

+                    }

+                }

+                NPNR_ASSERT(io_bel.index != -1);

+                auto io_bel_loc = ctx->getBelLocation(io_bel);

+

+                // Check that this SB_IO is either unused or just used as an output.

+                if (sb_io_used_by_io.count(io_bel_loc)) {

+                    log_error("SB_IO '%s' already in use, cannot route PLL through\n", ctx->getBelName(bel).c_str(ctx));

+                }

+                sb_io_used_by_pll.insert(io_bel_loc);

+

+                // Get IE/REN config location (cf. http://www.clifford.at/icestorm/io_tile.html)

+                auto ieren = get_ieren(bi, io_bel_loc.x, io_bel_loc.y, io_bel_loc.z);

+                int iex, iey, iez;

+                std::tie(iex, iey, iez) = ieren;

+                NPNR_ASSERT(iez != -1);

+

+                // Write config.

+                const TileInfoPOD &ti = bi.tiles_nonrouting[TILE_IO];

+                // Enable input buffer and disable pull-up resistor in block

+                // (this is used by the PLL).

+                set_ie_bit_logical(ctx, ti, config.at(iey).at(iex), "IoCtrl.IE_" + std::to_string(iez), true);

+                set_ie_bit_logical(ctx, ti, config.at(iey).at(iex), "IoCtrl.REN_" + std::to_string(iez), false);

+                // PINTYPE[0] passes the PLL through to the fabric.

+                set_config(ti, config.at(io_bel_loc.y).at(io_bel_loc.x),

+                           "IOB_" + std::to_string(io_bel_loc.z) + ".PINTYPE_0", true);

+            }

+

         } else {

             NPNR_ASSERT(false);

         }

@@ -416,14 +498,16 @@ void write_asc(const Context *ctx, std::ostream &out)
             const TileInfoPOD &ti = bi.tiles_nonrouting[TILE_IO];

             const BelInfoPOD &beli = ci.bel_data[bel.index];

             int x = beli.x, y = beli.y, z = beli.z;

+            if (sb_io_used_by_pll.count(Loc(x, y, z))) {

+                continue;

+            }

+

             auto ieren = get_ieren(bi, x, y, z);

             int iex, iey, iez;

             std::tie(iex, iey, iez) = ieren;

             if (iez != -1) {

-                if (ctx->args.type == ArchArgs::LP1K || ctx->args.type == ArchArgs::HX1K) {

-                    set_config(ti, config.at(iey).at(iex), "IoCtrl.IE_" + std::to_string(iez), true);

-                    set_config(ti, config.at(iey).at(iex), "IoCtrl.REN_" + std::to_string(iez), false);

-                }

+                set_ie_bit_logical(ctx, ti, config.at(iey).at(iex), "IoCtrl.IE_" + std::to_string(iez), true);

+                set_ie_bit_logical(ctx, ti, config.at(iey).at(iex), "IoCtrl.REN_" + std::to_string(iez), false);

             }

         } else if (ctx->bel_to_cell[bel.index] == IdString() && ctx->getBelType(bel) == TYPE_ICESTORM_RAM) {

             const BelInfoPOD &beli = ci.bel_data[bel.index];

diff --git a/ice40/cells.cc b/ice40/cells.cc
index 71a65d44..610bf85e 100644
--- a/ice40/cells.cc
+++ b/ice40/cells.cc
@@ -3,6 +3,7 @@
  *
  *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
  *  Copyright (C) 2018  David Shah <david@symbioticeda.com>
+ *  Copyright (C) 2018  Serge Bazanski <q3k@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
@@ -207,6 +208,40 @@ std::unique_ptr<CellInfo> create_ice_cell(Context *ctx, IdString type, std::stri
         add_port(ctx, new_cell.get(), "ACCUMCO", PORT_OUT);
         add_port(ctx, new_cell.get(), "SIGNEXTOUT", PORT_OUT);
 
+    } else if (type == ctx->id("ICESTORM_PLL")) {
+        new_cell->params[ctx->id("DELAY_ADJMODE_FB")] = "0";
+        new_cell->params[ctx->id("DELAY_ADJMODE_REL")] = "0";
+
+        new_cell->params[ctx->id("DIVF")] = "0";
+        new_cell->params[ctx->id("DIVQ")] = "0";
+        new_cell->params[ctx->id("DIVR")] = "0";
+
+        new_cell->params[ctx->id("FDA_FEEDBACK")] = "0";
+        new_cell->params[ctx->id("FDA_RELATIVE")] = "0";
+        new_cell->params[ctx->id("FEEDBACK_PATH")] = "0";
+        new_cell->params[ctx->id("FILTER_RANGE")] = "0";
+
+        new_cell->params[ctx->id("PLLOUT_SELECT_A")] = "0";
+        new_cell->params[ctx->id("PLLOUT_SELECT_B")] = "0";
+
+        new_cell->params[ctx->id("PLLTYPE")] = "0";
+        new_cell->params[ctx->id("SHIFTREG_DIVMODE")] = "0";
+        new_cell->params[ctx->id("TEST_MODE")] = "0";
+
+        add_port(ctx, new_cell.get(), "BYPASS", PORT_IN);
+        add_port(ctx, new_cell.get(), "DYNAMICDELAY", PORT_IN);
+        add_port(ctx, new_cell.get(), "EXTFEEDBACK", PORT_IN);
+        add_port(ctx, new_cell.get(), "LATCHINPUTVALUE", PORT_IN);
+        add_port(ctx, new_cell.get(), "REFERENCECLK", PORT_IN);
+        add_port(ctx, new_cell.get(), "RESETB", PORT_IN);
+
+        add_port(ctx, new_cell.get(), "SCLK", PORT_IN);
+        add_port(ctx, new_cell.get(), "SDI", PORT_IN);
+        add_port(ctx, new_cell.get(), "SDI", PORT_OUT);
+
+        add_port(ctx, new_cell.get(), "LOCK", PORT_OUT);
+        add_port(ctx, new_cell.get(), "PLLOUT_A", PORT_OUT);
+        add_port(ctx, new_cell.get(), "PLLOUT_B", PORT_OUT);
     } else {
         log_error("unable to create iCE40 cell of type %s", type.c_str(ctx));
     }
@@ -312,6 +347,21 @@ void nxio_to_sb(Context *ctx, CellInfo *nxio, CellInfo *sbio)
     }
 }
 
+uint8_t sb_pll40_type(const BaseCtx *ctx, const CellInfo *cell)
+{
+    if (cell->type == ctx->id("SB_PLL40_PAD"))
+        return 2;
+    if (cell->type == ctx->id("SB_PLL40_2_PAD"))
+        return 4;
+    if (cell->type == ctx->id("SB_PLL40_2F_PAD"))
+        return 5;
+    if (cell->type == ctx->id("SB_PLL40_CORE"))
+        return 3;
+    if (cell->type == ctx->id("SB_PLL40_2F_CORE"))
+        return 7;
+    NPNR_ASSERT(0);
+}
+
 bool is_clock_port(const BaseCtx *ctx, const PortRef &port)
 {
     if (port.cell == nullptr)
diff --git a/ice40/cells.h b/ice40/cells.h
index 2f9c77e8..16135448 100644
--- a/ice40/cells.h
+++ b/ice40/cells.h
@@ -71,6 +71,21 @@ inline bool is_sb_spram(const BaseCtx *ctx, const CellInfo *cell) { return cell-
 
 inline bool is_sb_mac16(const BaseCtx *ctx, const CellInfo *cell) { return cell->type == ctx->id("SB_MAC16"); }
 
+inline bool is_sb_pll40(const BaseCtx *ctx, const CellInfo *cell)
+{
+    return cell->type == ctx->id("SB_PLL40_PAD") || cell->type == ctx->id("SB_PLL40_2_PAD") ||
+           cell->type == ctx->id("SB_PLL40_2F_PAD") || cell->type == ctx->id("SB_PLL40_CORE") ||
+           cell->type == ctx->id("SB_PLL40_2F_CORE");
+}
+
+inline bool is_sb_pll40_pad(const BaseCtx *ctx, const CellInfo *cell)
+{
+    return cell->type == ctx->id("SB_PLL40_PAD") || cell->type == ctx->id("SB_PLL40_2_PAD") ||
+           cell->type == ctx->id("SB_PLL40_2F_PAD");
+}
+
+uint8_t sb_pll40_type(const BaseCtx *ctx, const CellInfo *cell);
+
 // 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
diff --git a/ice40/chipdb.py b/ice40/chipdb.py
index 1127767d..108197c1 100644
--- a/ice40/chipdb.py
+++ b/ice40/chipdb.py
@@ -182,6 +182,8 @@ def wire_type(name):
         wt = "LOCAL"
     elif name in ("WCLK", "WCLKE", "WE", "RCLK", "RCLKE", "RE"):
         wt = "LOCAL"
+    elif name in ("PLLOUT_A", "PLLOUT_B"):
+        wt = "LOCAL"
 
     if wt is None:
         print("No type for wire: %s (%s)" % (longname, name), file=sys.stderr)
@@ -584,6 +586,9 @@ def is_ec_output(ec_entry):
     if "glb_netwk_" in wirename: return True
     return False
 
+def is_ec_pll_clock_output(ec, ec_entry):
+    return ec[0] == 'PLL' and ec_entry[0] in ('PLLOUT_A', 'PLLOUT_B')
+
 def add_bel_ec(ec):
     ectype, x, y, z = ec
     bel = len(bel_name)
@@ -598,6 +603,10 @@ def add_bel_ec(ec):
                 add_bel_output(bel, wire_names[entry[1]], entry[0])
             else:
                 add_bel_input(bel, wire_names[entry[1]], entry[0])
+        elif is_ec_pll_clock_output(ec, entry):
+            x, y, z = entry[1]
+            z = 'io_{}/D_IN_0'.format(z)
+            add_bel_output(bel, wire_names[(x, y, z)], entry[0])
         else:
             extra_cell_config[bel].append(entry)
 
diff --git a/ice40/gfx.h b/ice40/gfx.h
index 8a55407d..7eeaccf1 100644
--- a/ice40/gfx.h
+++ b/ice40/gfx.h
@@ -464,7 +464,11 @@ enum GfxTileWireId
     TILE_WIRE_SP12_H_R_23,
 
     TILE_WIRE_SP12_H_L_22,
-    TILE_WIRE_SP12_H_L_23
+    TILE_WIRE_SP12_H_L_23,
+
+    TILE_WIRE_PLLIN,
+    TILE_WIRE_PLLOUT_A,
+    TILE_WIRE_PLLOUT_B
 };
 
 void gfxTileWire(std::vector<GraphicElement> &g, int x, int y, GfxTileWireId id, GraphicElement::style_t style);
diff --git a/ice40/pack.cc b/ice40/pack.cc
index f054be6b..b4f711f3 100644
--- a/ice40/pack.cc
+++ b/ice40/pack.cc
@@ -3,6 +3,7 @@
  *
  *  Copyright (C) 2018  Clifford Wolf <clifford@symbioticeda.com>
  *  Copyright (C) 2018  David Shah <david@symbioticeda.com>
+ *  Copyright (C) 2018  Serge Bazanski <q3k@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
@@ -540,6 +541,56 @@ static void promote_globals(Context *ctx)
     }
 }
 
+// spliceLUT adds a pass-through LUT LC between the given cell's output port
+// and either all users or only non_LUT users.
+static std::unique_ptr<CellInfo> spliceLUT(Context *ctx, CellInfo *ci, IdString portId, bool onlyNonLUTs)
+{
+    auto port = ci->ports[portId];
+
+    NPNR_ASSERT(port.net != nullptr);
+
+    // Create pass-through LUT.
+    std::unique_ptr<CellInfo> pt =
+            create_ice_cell(ctx, ctx->id("ICESTORM_LC"), ci->name.str(ctx) + "$nextpnr_ice40_pack_pll_lc");
+    pt->params[ctx->id("LUT_INIT")] = "255"; // output is always I3
+
+    // Create LUT output net.
+    std::unique_ptr<NetInfo> out_net = std::unique_ptr<NetInfo>(new NetInfo);
+    out_net->name = ctx->id(ci->name.str(ctx) + "$nextnr_ice40_pack_pll_net");
+    out_net->driver.cell = pt.get();
+    out_net->driver.port = ctx->id("O");
+    pt->ports.at(ctx->id("O")).net = out_net.get();
+
+    // New users of the original cell's port
+    std::vector<PortRef> new_users;
+    for (const auto &user : port.net->users) {
+        if (onlyNonLUTs && user.cell->type == ctx->id("ICESTORM_LC")) {
+            new_users.push_back(user);
+            continue;
+        }
+        // Rewrite pointer into net in user.
+        user.cell->ports[user.port].net = out_net.get();
+        // Add user to net.
+        PortRef pr;
+        pr.cell = user.cell;
+        pr.port = user.port;
+        out_net->users.push_back(pr);
+    }
+
+    // Add LUT to new users.
+    PortRef pr;
+    pr.cell = pt.get();
+    pr.port = ctx->id("I3");
+    new_users.push_back(pr);
+    pt->ports.at(ctx->id("I3")).net = port.net;
+
+    // Replace users of the original net.
+    port.net->users = new_users;
+
+    ctx->nets[out_net->name] = std::move(out_net);
+    return pt;
+}
+
 // Pack special functions
 static void pack_special(Context *ctx)
 {
@@ -595,6 +646,123 @@ static void pack_special(Context *ctx)
                 replace_port(ci, ctx->id(pi.name.c_str(ctx)), packed.get(), ctx->id(newname));
             }
             new_cells.push_back(std::move(packed));
+        } else if (is_sb_pll40(ctx, ci)) {
+            std::unique_ptr<CellInfo> packed =
+                    create_ice_cell(ctx, ctx->id("ICESTORM_PLL"), ci->name.str(ctx) + "_PLL");
+            packed_cells.insert(ci->name);
+
+            if (is_sb_pll40_pad(ctx, ci)) {
+                // TODO(q3k): Implement these after checking their behaviour on
+                // a board with exposed 'clock pads'.
+                log_error("SB_PLL40_*_PAD cells are not supported yet.\n");
+            }
+
+            for (auto attr : ci->attrs)
+                packed->attrs[attr.first] = attr.second;
+            for (auto param : ci->params)
+                packed->params[param.first] = param.second;
+
+            auto feedback_path = packed->params[ctx->id("FEEDBACK_PATH")];
+            packed->params[ctx->id("FEEDBACK_PATH")] =
+                    feedback_path == "DELAY"
+                            ? "0"
+                            : feedback_path == "SIMPLE" ? "1"
+                                                        : feedback_path == "PHASE_AND_DELAY"
+                                                                  ? "2"
+                                                                  : feedback_path == "EXTERNAL" ? "6" : feedback_path;
+            packed->params[ctx->id("PLLTYPE")] = std::to_string(sb_pll40_type(ctx, ci));
+
+            for (auto port : ci->ports) {
+                PortInfo &pi = port.second;
+                std::string newname = pi.name.str(ctx);
+                size_t bpos = newname.find('[');
+                if (bpos != std::string::npos) {
+                    newname = newname.substr(0, bpos) + "_" + newname.substr(bpos + 1, (newname.size() - bpos) - 2);
+                }
+                if (pi.name == ctx->id("PLLOUTCOREA"))
+                    newname = "PLLOUT_A";
+                if (pi.name == ctx->id("PLLOUTCOREB"))
+                    newname = "PLLOUT_B";
+                if (pi.name == ctx->id("PLLOUTCORE"))
+                    newname = "PLLOUT_A";
+                replace_port(ci, ctx->id(pi.name.c_str(ctx)), packed.get(), ctx->id(newname));
+            }
+
+            // If PLL is not constrained already, do that - we need this
+            // information to then constrain the LOCK LUT.
+            BelId pll_bel;
+            bool constrained = false;
+            if (packed->attrs.find(ctx->id("BEL")) == packed->attrs.end()) {
+                for (auto bel : ctx->getBels()) {
+                    if (ctx->getBelType(bel) != TYPE_ICESTORM_PLL)
+                        continue;
+                    log_info("  constrained '%s' to %s\n", packed->name.c_str(ctx), ctx->getBelName(bel).c_str(ctx));
+                    packed->attrs[ctx->id("BEL")] = ctx->getBelName(bel).str(ctx);
+                    pll_bel = bel;
+                    constrained = true;
+                }
+                if (!constrained) {
+                    log_error("  could not constrain '%s' to any PLL Bel\n", packed->name.c_str(ctx));
+                }
+            }
+
+            // The LOCK signal on iCE40 PLLs goes through the neigh_op_bnl_1 wire.
+            // In practice, this means the LOCK signal can only directly reach LUT
+            // inputs.
+            // If we have a net connected to LOCK, make sure it only drives LUTs.
+            auto port = packed->ports[ctx->id("LOCK")];
+            if (port.net != nullptr) {
+                bool found_lut = false;
+                bool all_luts = true;
+                unsigned int lut_count = 0;
+                for (const auto &user : port.net->users) {
+                    NPNR_ASSERT(user.cell != nullptr);
+                    if (user.cell->type == ctx->id("ICESTORM_LC")) {
+                        found_lut = true;
+                        lut_count++;
+                    } else {
+                        all_luts = false;
+                    }
+                }
+
+                if (found_lut && all_luts) {
+                    // Every user is a LUT, carry on now.
+                } else if (found_lut && !all_luts && lut_count < 8) {
+                    // Strategy: create a pass-through LUT, move all non-LUT users behind it.
+                    log_info("    LUT strategy for %s: move non-LUT users to new LUT\n", port.name.c_str(ctx));
+                    auto pt = spliceLUT(ctx, packed.get(), port.name, true);
+                    new_cells.push_back(std::move(pt));
+                } else {
+                    // Strategy: create a pass-through LUT, move every user behind it.
+                    log_info("    LUT strategy for %s: move all users to new LUT\n", port.name.c_str(ctx));
+                    auto pt = spliceLUT(ctx, packed.get(), port.name, false);
+                    new_cells.push_back(std::move(pt));
+                }
+
+                // Find wire that will be driven by this port.
+                const auto pll_out_wire = ctx->getBelPinWire(pll_bel, ctx->portPinFromId(port.name));
+                NPNR_ASSERT(pll_out_wire.index != -1);
+
+                // Now, constrain all LUTs on the output of the signal to be at
+                // the correct Bel relative to the PLL Bel.
+                int x = ctx->chip_info->wire_data[pll_out_wire.index].x;
+                int y = ctx->chip_info->wire_data[pll_out_wire.index].y;
+                int z = 0;
+                for (const auto &user : port.net->users) {
+                    NPNR_ASSERT(user.cell != nullptr);
+                    NPNR_ASSERT(user.cell->type == ctx->id("ICESTORM_LC"));
+
+                    // TODO(q3k): handle when the Bel might be already the
+                    // target of another constraint.
+                    NPNR_ASSERT(z < 8);
+                    auto target_bel = ctx->getBelByLocation(Loc(x, y, z++));
+                    auto target_bel_name = ctx->getBelName(target_bel).str(ctx);
+                    user.cell->attrs[ctx->id("BEL")] = target_bel_name;
+                    log_info("    constrained '%s' to %s\n", user.cell->name.c_str(ctx), target_bel_name.c_str());
+                }
+            }
+
+            new_cells.push_back(std::move(packed));
         }
     }
 
diff --git a/ice40/portpins.inc b/ice40/portpins.inc
index d78625d1..f9dac887 100644
--- a/ice40/portpins.inc
+++ b/ice40/portpins.inc
@@ -118,6 +118,8 @@ X(DYNAMICDELAY_5)
 X(DYNAMICDELAY_6)
 X(DYNAMICDELAY_7)
 X(LOCK)
+X(PLLOUT_A)
+X(PLLOUT_B)
 X(BYPASS)
 X(RESETB)
 X(LATCHINPUTVALUE)