nextpnr/himbaechel/uarch/gatemate/pack_io.cc

570 lines
25 KiB
C++

/*
* nextpnr -- Next Generation Place and Route
*
* Copyright (C) 2024 The Project Peppercorn Authors.
*
* 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"
#define HIMBAECHEL_CONSTIDS "uarch/gatemate/constids.inc"
#include "himbaechel_constids.h"
NEXTPNR_NAMESPACE_BEGIN
BelId GateMatePacker::get_bank_cpe(int bank)
{
switch (bank) {
case 0:
return ctx->getBelByLocation(Loc(97 + 2, 128 + 2, 1)); // N1, RAM_O1
case 1:
return ctx->getBelByLocation(Loc(97 + 2, 128 + 2, 0)); // N2, RAM_O2
case 2:
return ctx->getBelByLocation(Loc(160 + 2, 65 + 2, 1)); // E1, RAM_O1
case 3:
return ctx->getBelByLocation(Loc(160 + 2, 65 + 2, 0)); // E2, RAM_O2
case 4:
return ctx->getBelByLocation(Loc(1 + 2, 65 + 2, 1)); // W1, RAM_O1
case 5:
return ctx->getBelByLocation(Loc(1 + 2, 65 + 2, 0)); // W2, RAM_O2
case 6:
return ctx->getBelByLocation(Loc(97 + 2, 1 + 2, 1)); // S1, RAM_O1
case 7:
return ctx->getBelByLocation(Loc(97 + 2, 1 + 2, 0)); // S2, RAM_O2
case 8:
return ctx->getBelByLocation(Loc(49 + 2, 1 + 2, 1)); // S3, RAM_O1
default:
log_error("Unkown bank\n");
}
}
void GateMatePacker::pack_io()
{
// Trim nextpnr IOBs - assume IO buffer insertion has been done in synthesis
for (auto &port : ctx->ports) {
if (!ctx->cells.count(port.first))
log_error("Port '%s' doesn't seem to have a corresponding top level IO\n", ctx->nameOf(port.first));
CellInfo *ci = ctx->cells.at(port.first).get();
PortRef top_port;
top_port.cell = nullptr;
bool is_npnr_iob = false;
if (ci->type == ctx->id("$nextpnr_ibuf") || ci->type == ctx->id("$nextpnr_iobuf")) {
// Might have an input buffer connected to it
is_npnr_iob = true;
NetInfo *o = ci->getPort(id_O);
if (o == nullptr)
;
else if (o->users.entries() > 1)
log_error("Top level pin '%s' has multiple input buffers\n", ctx->nameOf(port.first));
else if (o->users.entries() == 1)
top_port = *o->users.begin();
}
if (ci->type == ctx->id("$nextpnr_obuf") || ci->type == ctx->id("$nextpnr_iobuf")) {
// Might have an output buffer connected to it
is_npnr_iob = true;
NetInfo *i = ci->getPort(id_I);
if (i != nullptr && i->driver.cell != nullptr) {
if (top_port.cell != nullptr)
log_error("Top level pin '%s' has multiple input/output buffers\n", ctx->nameOf(port.first));
top_port = i->driver;
}
// Edge case of a bidirectional buffer driving an output pin
if (i->users.entries() > 2) {
log_error("Top level pin '%s' has illegal buffer configuration\n", ctx->nameOf(port.first));
} else if (i->users.entries() == 2) {
if (top_port.cell != nullptr)
log_error("Top level pin '%s' has illegal buffer configuration\n", ctx->nameOf(port.first));
for (auto &usr : i->users) {
if (usr.cell->type == ctx->id("$nextpnr_obuf") || usr.cell->type == ctx->id("$nextpnr_iobuf"))
continue;
top_port = usr;
break;
}
}
}
if (!is_npnr_iob)
log_error("Port '%s' doesn't seem to have a corresponding top level IO (internal cell type mismatch)\n",
ctx->nameOf(port.first));
if (top_port.cell == nullptr) {
log_info("Trimming port '%s' as it is unused.\n", ctx->nameOf(port.first));
} else {
// Copy attributes to real IO buffer
for (auto &attrs : ci->attrs)
top_port.cell->attrs[attrs.first] = attrs.second;
for (auto &params : ci->params) {
IdString key = params.first;
if (key == id_LOC &&
top_port.cell->type.in(id_CC_LVDS_IBUF, id_CC_LVDS_OBUF, id_CC_LVDS_TOBUF, id_CC_LVDS_IOBUF)) {
if (top_port.port.in(id_I_P, id_O_P, id_IO_P))
key = id_PIN_NAME_P;
if (top_port.port.in(id_I_N, id_O_N, id_IO_N))
key = id_PIN_NAME_N;
}
if (top_port.cell->params.count(key)) {
if (top_port.cell->params[key] != params.second) {
std::string val = params.second.is_string ? params.second.as_string()
: std::to_string(params.second.as_int64());
log_warning("Overriding parameter '%s' with value '%s' for cell '%s'.\n", key.c_str(ctx),
val.c_str(), ctx->nameOf(top_port.cell));
}
}
top_port.cell->params[key] = params.second;
}
// Make sure that top level net is set correctly
port.second.net = top_port.cell->ports.at(top_port.port).net;
}
// Now remove the nextpnr-inserted buffer
ci->disconnectPort(id_I);
ci->disconnectPort(id_O);
ctx->cells.erase(port.first);
}
for (auto &cell : ctx->cells) {
CellInfo &ci = *cell.second;
if (!ci.type.in(id_CC_IBUF, id_CC_OBUF, id_CC_TOBUF, id_CC_IOBUF, id_CC_LVDS_IBUF, id_CC_LVDS_OBUF,
id_CC_LVDS_TOBUF, id_CC_LVDS_IOBUF))
continue;
bool is_lvds = ci.type.in(id_CC_LVDS_IBUF, id_CC_LVDS_OBUF, id_CC_LVDS_TOBUF, id_CC_LVDS_IOBUF);
std::string loc = str_or_default(ci.params, is_lvds ? id_PIN_NAME_P : id_PIN_NAME, "UNPLACED");
if (ci.params.count(id_LOC)) {
std::string new_loc = str_or_default(ci.params, id_LOC, "UNPLACED");
if (loc != "UNPLACED" && loc != new_loc)
log_warning("Overriding location of cell '%s' from '%s' with '%s'\n", ctx->nameOf(&ci), loc.c_str(),
new_loc.c_str());
loc = new_loc;
}
if (loc == "UNPLACED") {
const ArchArgs &args = ctx->args;
if (args.options.count("allow-unconstrained"))
log_warning("IO '%s' is unconstrained in CCF and will be automatically placed.\n", ctx->nameOf(&ci));
else
log_error("IO '%s' is unconstrained in CCF (override this error with "
"--vopt allow-unconstrained).\n",
ctx->nameOf(&ci));
}
disconnect_if_gnd(&ci, id_T);
if (ci.type == id_CC_TOBUF && !ci.getPort(id_T))
ci.type = id_CC_OBUF;
if (ci.type == id_CC_LVDS_TOBUF && !ci.getPort(id_T))
ci.type = id_CC_LVDS_OBUF;
if (ci.type.in(id_CC_IBUF, id_CC_IOBUF))
copy_constraint(ci.getPort(id_I), ci.getPort(id_Y));
if (ci.type.in(id_CC_LVDS_IBUF, id_CC_LVDS_IOBUF)) {
copy_constraint(ci.getPort(id_I_P), ci.getPort(id_Y));
copy_constraint(ci.getPort(id_I_N), ci.getPort(id_Y));
}
std::vector<IdString> keys;
for (auto &p : ci.params) {
if (p.first.in(id_PIN_NAME, id_PIN_NAME_P, id_PIN_NAME_N)) {
if (ctx->get_package_pin_bel(ctx->id(p.second.as_string())) == BelId())
log_error("Unknown %s '%s' for cell '%s'.\n", p.first.c_str(ctx), p.second.as_string().c_str(),
ci.name.c_str(ctx));
keys.push_back(p.first);
continue;
}
if (p.first.in(id_V_IO, id_LOC)) {
keys.push_back(p.first);
continue;
}
if (ci.type.in(id_CC_IBUF, id_CC_IOBUF) &&
p.first.in(id_PULLUP, id_PULLDOWN, id_KEEPER, id_SCHMITT_TRIGGER, id_DELAY_IBF, id_FF_IBF))
continue;
if (ci.type.in(id_CC_TOBUF) && p.first.in(id_PULLUP, id_PULLDOWN, id_KEEPER))
continue;
if (ci.type.in(id_CC_OBUF, id_CC_TOBUF, id_CC_IOBUF) &&
p.first.in(id_DRIVE, id_SLEW, id_DELAY_OBF, id_FF_OBF))
continue;
if (ci.type.in(id_CC_LVDS_IBUF, id_CC_LVDS_IOBUF) && p.first.in(id_LVDS_RTERM, id_DELAY_IBF, id_FF_IBF))
continue;
if (ci.type.in(id_CC_LVDS_OBUF, id_CC_LVDS_TOBUF, id_CC_LVDS_IOBUF) &&
p.first.in(id_LVDS_BOOST, id_DELAY_OBF, id_FF_OBF))
continue;
log_warning("Removing unsupported parameter '%s' for type '%s'.\n", p.first.c_str(ctx), ci.type.c_str(ctx));
keys.push_back(p.first);
}
if (ci.params.count(id_SLEW)) {
std::string val = str_or_default(ci.params, id_SLEW, "UNDEFINED");
if (val == "UNDEFINED")
keys.push_back(id_SLEW);
else if (val == "FAST")
ci.params[id_SLEW] = Property(Property::State::S0);
else if (val == "SLOW")
ci.params[id_SLEW] = Property(Property::State::S1);
else
log_error("Unknown value '%s' for SLEW parameter of '%s' cell.\n", val.c_str(), ci.name.c_str(ctx));
}
if (is_lvds) {
std::string p_pin = str_or_default(ci.params, id_PIN_NAME_P, "UNPLACED");
std::string n_pin = str_or_default(ci.params, id_PIN_NAME_N, "UNPLACED");
if (p_pin == "UNPLACED" || n_pin == "UNPLACED")
log_error("Both LVDS pins must be set to a valid locations.\n");
if (p_pin.substr(0, 6) != n_pin.substr(0, 6) || p_pin[7] != n_pin[7])
log_error("LVDS pads '%s' and '%s' do not match.\n", p_pin.c_str(), n_pin.c_str());
if (p_pin[6] != 'A')
log_error("LVDS positive pad must be from type A.\n");
if (n_pin[6] != 'B')
log_error("LVDS negative pad must be from type B.\n");
}
for (auto key : keys)
ci.params.erase(key);
// For output pins set SLEW to SLOW if not defined
if (!ci.params.count(id_SLEW) && ci.type.in(id_CC_OBUF, id_CC_TOBUF, id_CC_IOBUF))
ci.params[id_SLEW] = Property(Property::State::S1);
if ((ci.params.count(id_KEEPER) + ci.params.count(id_PULLUP) + ci.params.count(id_PULLDOWN)) > 1)
log_error("PULLUP, PULLDOWN and KEEPER are mutually exclusive parameters.\n");
if (is_lvds)
ci.params[id_LVDS_EN] = Property(Property::State::S1);
// DELAY_IBF and DELAY_OBF must be set depending of type
// Also we need to enable input/output
if (ci.type.in(id_CC_IBUF, id_CC_IOBUF, id_CC_LVDS_IBUF, id_CC_LVDS_IOBUF)) {
ci.params[id_DELAY_IBF] = Property(1 << int_or_default(ci.params, id_DELAY_IBF, 0), 16);
if (is_lvds)
ci.params[id_LVDS_IE] = Property(Property::State::S1);
else
ci.params[id_INPUT_ENABLE] = Property(Property::State::S1);
}
if (ci.type.in(id_CC_OBUF, id_CC_TOBUF, id_CC_IOBUF, id_CC_LVDS_OBUF, id_CC_LVDS_TOBUF, id_CC_LVDS_IOBUF)) {
ci.params[id_DELAY_OBF] = Property(1 << int_or_default(ci.params, id_DELAY_OBF, 0), 16);
ci.params[id_OE_ENABLE] = Property(Property::State::S1);
}
if (ci.params.count(id_DRIVE)) {
int val = int_or_default(ci.params, id_DRIVE, 0);
if (val != 3 && val != 6 && val != 9 && val != 12)
log_error("Unsupported value '%d' for DRIVE parameter of '%s' cell.\n", val, ci.name.c_str(ctx));
ci.params[id_DRIVE] = Property((val - 3) / 3, 2);
}
for (auto &p : ci.params) {
if (p.first.in(id_PULLUP, id_PULLDOWN, id_KEEPER, id_SCHMITT_TRIGGER, id_FF_OBF, id_FF_IBF, id_LVDS_RTERM,
id_LVDS_BOOST)) {
int val = int_or_default(ci.params, p.first, 0);
if (val != 0 && val != 1)
log_error("Unsupported value '%d' for %s parameter of '%s' cell.\n", val, p.first.c_str(ctx),
ci.name.c_str(ctx));
ci.params[p.first] = Property(val, 1);
}
}
// Disconnect PADs
ci.disconnectPort(id_IO);
ci.disconnectPort(id_I);
ci.disconnectPort(id_O);
ci.disconnectPort(id_IO_P);
ci.disconnectPort(id_IO_N);
ci.disconnectPort(id_I_P);
ci.disconnectPort(id_I_N);
ci.disconnectPort(id_O_P);
ci.disconnectPort(id_O_N);
if (loc.empty() || loc == "UNPLACED") {
if (uarch->available_pads.empty())
log_error("No more pads available.\n");
IdString id = *(uarch->available_pads.begin());
uarch->available_pads.erase(id);
loc = id.c_str(ctx);
}
ci.params[id_LOC] = Property(loc);
BelId bel = ctx->get_package_pin_bel(ctx->id(loc));
if (bel == BelId())
log_error("Unable to constrain IO '%s', device does not have a pin named '%s'\n", ci.name.c_str(ctx),
loc.c_str());
log_info(" Constraining '%s' to pad '%s'\n", ci.name.c_str(ctx), loc.c_str());
if (!ctx->checkBelAvail(bel)) {
log_error("Can't place %s at %s because it's already taken by %s\n", ctx->nameOf(&ci), ctx->nameOfBel(bel),
ctx->nameOf(ctx->getBoundBelCell(bel)));
}
ctx->bindBel(bel, &ci, PlaceStrength::STRENGTH_FIXED);
}
}
void GateMatePacker::pack_io_sel()
{
std::vector<CellInfo *> cells;
for (auto &cell : ctx->cells) {
CellInfo &ci = *cell.second;
if (!ci.type.in(id_CC_IBUF, id_CC_OBUF, id_CC_TOBUF, id_CC_IOBUF, id_CC_LVDS_IBUF, id_CC_LVDS_OBUF,
id_CC_LVDS_TOBUF, id_CC_LVDS_IOBUF))
continue;
cells.push_back(&ci);
}
CellInfo *ddr[9] = {nullptr}; // for each bank
auto set_out_clk = [&](CellInfo *cell, CellInfo *target) -> bool {
NetInfo *clk_net = cell->getPort(id_CLK);
if (clk_net) {
if (clk_net->name == ctx->id("$PACKER_GND")) {
cell->disconnectPort(id_CLK);
} else if (clk_net->name == ctx->id("$PACKER_VCC")) {
cell->disconnectPort(id_CLK);
} else {
if (!global_signals.count(clk_net)) {
cell->movePortTo(id_CLK, target, id_OUT4);
target->params[id_SEL_OUT_CLOCK] = Property(Property::State::S1);
return true;
} else {
int index = global_signals[clk_net];
cell->movePortTo(id_CLK, target, ctx->idf("CLOCK%d", index + 1));
target->params[id_OUT_CLOCK] = Property(index, 2);
}
}
}
return false;
};
auto set_in_clk = [&](CellInfo *cell, CellInfo *target) {
NetInfo *clk_net = cell->getPort(id_CLK);
if (clk_net) {
if (clk_net->name == ctx->id("$PACKER_GND")) {
cell->disconnectPort(id_CLK);
} else if (clk_net->name == ctx->id("$PACKER_VCC")) {
cell->disconnectPort(id_CLK);
} else {
if (!global_signals.count(clk_net)) {
cell->movePortTo(id_CLK, target, id_OUT4);
target->params[id_SEL_IN_CLOCK] = Property(Property::State::S1);
} else {
int index = global_signals[clk_net];
cell->movePortTo(id_CLK, target, ctx->idf("CLOCK%d", index + 1));
target->params[id_IN_CLOCK] = Property(index, 2);
}
}
}
};
auto merge_ibf = [&](NetInfo *di_net, CellInfo &ci, bool use_custom_clock) -> bool {
CellInfo *dff = (*di_net->users.begin()).cell;
if (is_gpio_valid_dff(dff)) {
if (!global_signals.count(ci.getPort(id_CLK)) && use_custom_clock) {
log_warning("Found DFF %s cell, but not enough CLK signals.\n", dff->name.c_str(ctx));
return false;
}
// We configure both GPIO IN and let router decide
ci.params[id_IN1_FF] = Property(Property::State::S1);
ci.params[id_IN2_FF] = Property(Property::State::S1);
packed_cells.emplace(dff->name);
ci.disconnectPort(id_Y);
dff->movePortTo(id_Q, &ci, id_DI);
set_in_clk(dff, &ci);
bool invert = bool_or_default(dff->params, id_CLK_INV, 0);
if (invert) {
ci.params[id_INV_IN1_CLOCK] = Property(Property::State::S1);
ci.params[id_INV_IN2_CLOCK] = Property(Property::State::S1);
}
return true;
} else {
log_warning("DFF '%s' cell for IO '%s', but unable to merge.\n", dff->name.c_str(ctx), ci.name.c_str(ctx));
}
return false;
};
auto merge_iddr = [&](NetInfo *di_net, CellInfo &ci, bool use_custom_clock) -> bool {
CellInfo *iddr = (*di_net->users.begin()).cell;
if (!global_signals.count(ci.getPort(id_CLK)) && use_custom_clock) {
log_warning("Found IDDR %s cell, but not enough CLK signals.\n", iddr->name.c_str(ctx));
return false;
}
ci.params[id_IN1_FF] = Property(Property::State::S1);
ci.params[id_IN2_FF] = Property(Property::State::S1);
packed_cells.emplace(iddr->name);
ci.disconnectPort(id_Y);
iddr->movePortTo(id_Q0, &ci, id_IN1);
iddr->movePortTo(id_Q1, &ci, id_IN2);
set_in_clk(iddr, &ci);
bool invert = bool_or_default(iddr->params, id_CLK_INV, 0);
if (invert) {
ci.params[id_INV_IN1_CLOCK] = Property(Property::State::S1);
} else {
ci.params[id_INV_IN2_CLOCK] = Property(Property::State::S1);
}
return false;
};
for (auto &cell : cells) {
CellInfo &ci = *cell;
bool ff_obf = bool_or_default(ci.params, id_FF_OBF, 0);
bool ff_ibf = bool_or_default(ci.params, id_FF_IBF, 0);
ci.unsetParam(id_FF_OBF);
ci.unsetParam(id_FF_IBF);
if (ci.getPort(id_T)) {
ci.params[id_OE_SIGNAL] = Property(0b10, 2);
ci.renamePort(id_T, id_OUT3);
}
ci.cluster = ci.name;
std::string loc = str_or_default(ci.params, id_LOC, "UNPLACED");
ci.unsetParam(id_LOC);
NetInfo *do_net = ci.getPort(id_A);
bool use_custom_clock = false;
if (do_net) {
if (do_net->name.in(ctx->id("$PACKER_GND"), ctx->id("$PACKER_VCC"))) {
ci.params[id_OUT23_14_SEL] =
Property(do_net->name == ctx->id("$PACKER_VCC") ? Property::State::S1 : Property::State::S0);
ci.disconnectPort(id_A);
} else {
ci.params[id_OUT_SIGNAL] = Property(Property::State::S1);
bool ff_obf_merged = false;
if (ff_obf && do_net->driver.cell->type == id_CC_DFF && do_net->users.entries() == 1) {
CellInfo *dff = do_net->driver.cell;
if (is_gpio_valid_dff(dff)) {
ci.params[id_OUT1_FF] = Property(Property::State::S1);
packed_cells.emplace(dff->name);
ci.disconnectPort(id_A);
dff->movePortTo(id_D, &ci, id_OUT1);
use_custom_clock = set_out_clk(dff, &ci);
bool invert = bool_or_default(dff->params, id_CLK_INV, 0);
if (invert) {
ci.params[id_INV_OUT1_CLOCK] = Property(Property::State::S1);
ci.params[id_INV_OUT2_CLOCK] = Property(Property::State::S1);
}
ff_obf_merged = true;
} else {
log_warning("DFF '%s' cell for IO '%s', but unable to merge.\n", dff->name.c_str(ctx),
ci.name.c_str(ctx));
}
}
bool oddr_merged = false;
if (do_net->driver.cell->type == id_CC_ODDR && do_net->users.entries() == 1) {
CellInfo *oddr = do_net->driver.cell;
ci.params[id_OUT1_FF] = Property(Property::State::S1);
ci.params[id_OUT2_FF] = Property(Property::State::S1);
ci.params[id_USE_DDR] = Property(Property::State::S1);
packed_cells.emplace(oddr->name);
ci.disconnectPort(id_A);
oddr->movePortTo(id_D0, &ci, id_OUT2);
oddr->movePortTo(id_D1, &ci, id_OUT1);
const auto &pad = ctx->get_package_pin(ctx->id(loc));
CellInfo *cpe_half = ddr[pad->pad_bank];
if (cpe_half) {
if (cpe_half->getPort(id_IN1) != oddr->getPort(id_DDR))
log_error("DDR port use signal different than already occupied DDR source.\n");
ci.ports[id_DDR].name = id_DDR;
ci.ports[id_DDR].type = PORT_IN;
ci.connectPort(id_DDR, cpe_half->getPort(id_RAM_O));
} else {
oddr->movePortTo(id_DDR, &ci, id_DDR);
cpe_half = move_ram_o(&ci, id_DDR, false);
ctx->bindBel(get_bank_cpe(pad->pad_bank), cpe_half, PlaceStrength::STRENGTH_FIXED);
ddr[pad->pad_bank] = cpe_half;
}
use_custom_clock = set_out_clk(oddr, &ci);
bool invert = bool_or_default(oddr->params, id_CLK_INV, 0);
if (!invert) {
ci.params[id_INV_OUT1_CLOCK] = Property(Property::State::S1);
} else {
ci.params[id_INV_OUT2_CLOCK] = Property(Property::State::S1);
}
oddr_merged = true;
}
if (!ff_obf_merged && !oddr_merged)
ci.renamePort(id_A, id_OUT1);
}
}
NetInfo *di_net = ci.getPort(id_Y);
if (di_net) {
bool ff_ibf_merged = false;
if (ff_ibf && di_net->users.entries() == 1 && (*di_net->users.begin()).cell->type == id_CC_DFF) {
ff_ibf_merged = merge_ibf(di_net, ci, use_custom_clock);
}
bool iddr_merged = false;
if (di_net->users.entries() == 1 && (*di_net->users.begin()).cell->type == id_CC_IDDR) {
iddr_merged = merge_iddr(di_net, ci, use_custom_clock);
}
if (!ff_ibf_merged && !iddr_merged)
ci.renamePort(id_Y, id_DI);
}
Loc root_loc = ctx->getBelLocation(ci.bel);
for (int i = 0; i < 4; i++) {
CellInfo *cpe = move_ram_o_fixed(&ci, ctx->idf("OUT%d", i + 1), root_loc);
if (cpe && i == 2)
cpe->params[id_INIT_L10] = Property(0b0101, 4); // Invert CPE out for output enable (OUT3)
}
}
flush_cells();
}
bool GateMatePacker::is_gpio_valid_dff(CellInfo *dff)
{
NetInfo *en_net = dff->getPort(id_EN);
bool invert = bool_or_default(dff->params, id_EN_INV, 0);
if (en_net) {
if (en_net->name == ctx->id("$PACKER_GND")) {
if (!invert)
return false;
dff->disconnectPort(id_EN);
} else if (en_net->name == ctx->id("$PACKER_VCC")) {
if (invert)
return false;
dff->disconnectPort(id_EN);
} else {
return false;
}
}
dff->unsetParam(id_EN_INV);
NetInfo *sr_net = dff->getPort(id_SR);
invert = bool_or_default(dff->params, id_SR_INV, 0);
if (sr_net) {
if (sr_net->name.in(ctx->id("$PACKER_GND"), ctx->id("$PACKER_VCC"))) {
bool sr_signal = sr_net->name == ctx->id("$PACKER_VCC");
if (sr_signal ^ invert)
log_error("Currently unsupported DFF configuration for '%s'\n.", dff->name.c_str(ctx));
dff->disconnectPort(id_SR);
} else {
return false;
}
}
dff->unsetParam(id_SR_VAL);
dff->unsetParam(id_SR_INV);
// Sanity check for CLK signal, that it must exist
NetInfo *clk_net = dff->getPort(id_CLK);
if (clk_net) {
if (clk_net->name == ctx->id("$PACKER_GND")) {
return false;
} else if (clk_net->name == ctx->id("$PACKER_VCC")) {
return false;
}
} else {
return false;
}
return true;
}
NEXTPNR_NAMESPACE_END