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Adding IO buffer insertion function to JSON frontend

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Signed-off-by: David Shah <davey1576@gmail.com>
This commit is contained in:
David Shah 2018-06-13 09:42:33 +02:00
parent 0bf54951cf
commit 0aec418ee3
1 changed files with 55 additions and 0 deletions
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55
frontend/json/jsonparse.cc
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@ -640,6 +640,61 @@ void json_import_cell(Design *design, string modname, JsonNode *cell_node,
// check_all_nets_driven(design);
}
static void insert_iobuf(Design *design, NetInfo *net, PortType type,
string name)
{
// Instantiate a architecture-independent IO buffer connected to a given
// net, of a given type, and named after the IO port.
//
// During packing, this generic IO buffer will be converted to an
// architecure primitive.
//
CellInfo *iobuf = new CellInfo();
iobuf->name = name;
std::copy(net->attrs.begin(), net->attrs.end(),
std::inserter(iobuf->attrs, iobuf->attrs.begin()));
if (type == PORT_IN) {
iobuf->type = "$nextpnr_ibuf";
iobuf->ports["O"] = PortInfo{"O", net, PORT_OUT};
assert(net->driver.cell == nullptr);
net->driver.port = "O";
net->driver.cell = iobuf;
} else if (type == PORT_OUT) {
iobuf->type == "$nextpnr_obuf";
iobuf->ports["I"] = PortInfo{"I", net, PORT_IN};
PortRef ref;
ref.cell = iobuf;
ref.port = "I";
net->users.push_back(ref);
} else if (type == PORT_INOUT) {
iobuf->type == "$nextpnr_iobuf";
iobuf->ports["I"] = PortInfo{"I", nullptr, PORT_IN};
if (net->driver.cell != NULL) {
// Split the input and output nets for bidir ports
NetInfo *net2 = new NetInfo();
net2->name = "$" + net->name.str() + "$iobuf_i";
net2->driver = net->driver;
net2->driver.cell->ports[net2->driver.port].net = net2;
net->driver.cell = nullptr;
design->nets[net2->name] = net2;
iobuf->ports["I"].net = net2;
PortRef ref;
ref.cell = iobuf;
ref.port = "I";
net2->users.push_back(ref);
}
iobuf->ports["O"] = PortInfo{"O", net, PORT_OUT};
assert(net->driver.cell == nullptr);
net->driver.port = "O";
net->driver.cell = iobuf;
} else {
assert(false);
}
design->cells[iobuf->name] = iobuf;
}
void json_import(Design *design, string modname, JsonNode *node)
{
if (is_blackbox(node))