caiyu/nextpnr
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Fixing implementation of constants

Browse Source 
Signed-off-by: David Shah <davey1576@gmail.com>
This commit is contained in:
David Shah 2018-06-13 14:01:42 +02:00
parent 991cf1979b
commit 9374ef29bf
4 changed files with 55 additions and 9 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
frontend/json/jsonparse.cc
View File

@ -341,6 +341,8 @@ void json_import_cell_params(Design *design, string &modname, CellInfo *cell,
modname.c_str());
}
static int const_net_idx = 0;
template <typename F>
void json_import_ports(Design *design, const string &modname,
const string &obj_name, const string &port_name,
@ -466,7 +468,7 @@ void json_import_ports(Design *design, const string &modname,
//
// Constants always get their own new net
this_net = new NetInfo;
this_net->name = net_id;
this_net->name = "$const_" + std::to_string(const_net_idx++);
const_input = (this_port.type == PORT_IN);
if (wire_node->data_string.compare(string("0")) == 0) {

5
ice40/icebreaker.pcf
View File

@ -3,7 +3,12 @@ set_io led2 25
set_io led3 21
set_io led4 23
set_io led5 26
set_io ledr 11
set_io ledg 37
set_io clki 35
set_io btn1 20
set_io btn2 19
set_io btn3 18
set_io btn_n 10

9
ice40/icebreaker.v
View File

@ -3,11 +3,15 @@ module icebreaker (
input btn1,
input btn2,
input btn3,
input btn_n,
output led1,
output led2,
output led3,
output led4,
output led5
output led5,
output ledr,
output ledg,
);
wire clk;
SB_GB clk_gb(.USER_SIGNAL_TO_GLOBAL_BUFFER(clki), .GLOBAL_BUFFER_OUTPUT(clk));
@ -22,5 +26,6 @@ module icebreaker (
outcnt <= counter >> LOG2DELAY;
end
assign {led1, led2, led3, led4, led5} = outcnt ^ (outcnt >> 1);
//assign {led1, led2, led3, led4, led5} = {!btn1, btn2, btn3, btn2, btn1};
assign {ledr, ledg} = ~(!btn_n + btn1 + btn2 + btn3);
endmodule

46
ice40/pack.cc
View File

@ -110,28 +110,62 @@ static void pack_nonlut_ffs(Design *design)
}
}
// Merge a net into a constant net
static void set_net_constant(NetInfo *orig, NetInfo *constnet, bool constval)
{
orig->driver.cell = nullptr;
for (auto user : orig->users) {
if (user.cell != nullptr) {
CellInfo *uc = user.cell;
log_info("%s user %s\n", orig->name.c_str(), uc->name.c_str());
if (is_lut(uc) && (user.port.str().at(0) == 'I') && !constval) {
uc->ports[user.port].net = nullptr;
} else {
uc->ports[user.port].net = constnet;
constnet->users.push_back(user);
}
}
}
orig->users.clear();
}
// Pack constants (simple implementation)
static void pack_constants(Design *design)
{
CellInfo *gnd_cell = create_ice_cell(design, "ICESTORM_LC", "$PACKER_GND");
gnd_cell->attrs["LUT_INIT"] = "0";
gnd_cell->params["LUT_INIT"] = "0";
NetInfo *gnd_net = new NetInfo;
gnd_net->name = "$PACKER_GND_NET";
gnd_net->driver.cell = gnd_cell;
gnd_net->driver.port = "O";
CellInfo *vcc_cell = create_ice_cell(design, "ICESTORM_LC", "$PACKER_VCC");
vcc_cell->attrs["LUT_INIT"] = "1";
vcc_cell->params["LUT_INIT"] = "1";
NetInfo *vcc_net = new NetInfo;
vcc_net->name = "$PACKER_VCC_NET";
vcc_net->driver.cell = vcc_cell;
vcc_net->driver.port = "O";
std::vector<IdString> dead_nets;
for (auto net : design->nets) {
NetInfo *ni = net.second;
if (ni->driver.cell != nullptr && ni->driver.cell->type == "GND") {
ni->driver.cell = gnd_cell;
ni->driver.port = "O";
set_net_constant(ni, gnd_net, false);
design->cells[gnd_cell->name] = gnd_cell;
design->nets[gnd_net->name] = gnd_net;
dead_nets.push_back(net.first);
} else if (ni->driver.cell != nullptr &&
ni->driver.cell->type == "VCC") {
ni->driver.cell = vcc_cell;
ni->driver.port = "O";
set_net_constant(ni, vcc_net, true);
design->cells[vcc_cell->name] = vcc_cell;
design->nets[vcc_net->name] = vcc_net;
dead_nets.push_back(net.first);
}
}
for (auto dn : dead_nets)
design->nets.erase(dn);
}
static bool is_nextpnr_iob(CellInfo *cell)