add UART example

This commit is contained in:
Sebastien Bourdeauducq 2019-03-25 16:10:07 +08:00
parent 38ccee5c01
commit b2bcbd7048
2 changed files with 89 additions and 0 deletions

48
examples/demo.nix Normal file
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{ pkgs ? import <nixpkgs> {}
, hx ? import ../default.nix { inherit pkgs; }}:
let
vivadoInput = pkgs.runCommand "test-vivado-input" {
buildInputs = [ (pkgs.python3.withPackages(ps: [hx.nmigen hx.heavycomps])) hx.yosys ];
}
''
mkdir $out
python ${./demo.py} > $out/top.v
cat > $out/top.xdc << EOF
set_property LOC K24 [get_ports serial_tx]
set_property IOSTANDARD LVCMOS25 [get_ports serial_tx]
set_property LOC K28 [get_ports clk156_p]
set_property IOSTANDARD LVDS_25 [get_ports clk156_p]
set_property DIFF_TERM TRUE [get_ports clk156_p]
set_property LOC K29 [get_ports clk156_n]
set_property IOSTANDARD LVDS_25 [get_ports clk156_n]
set_property DIFF_TERM TRUE [get_ports clk156_n]
create_clock -name clk156 -period 6.4 [get_nets clk156_p]
EOF
cat > $out/top.tcl << EOF
create_project -force -name top -part xc7k325t-ffg900-2
set_property XPM_LIBRARIES {XPM_CDC XPM_MEMORY} [current_project]
add_files {top.v}
set_property library work [get_files {top.v}]
read_xdc top.xdc
synth_design -top top -part xc7k325t-ffg900-2
opt_design
place_design
route_design
set_property BITSTREAM.CONFIG.SPI_BUSWIDTH 4 [current_design]
set_property BITSTREAM.GENERAL.COMPRESS True [current_design]
write_bitstream -force top.bit
quit
EOF
'';
in
hx.vivado.buildBitstream {
name = "test-design";
src = vivadoInput;
}

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examples/demo.py Normal file
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from nmigen import *
from nmigen.back import verilog
from heavycomps import uart
class Top:
def __init__(self, clk_freq=156e6, baudrate=115200):
self.clk_freq = clk_freq
self.baudrate = baudrate
self.clk156_p = Signal()
self.clk156_n = Signal()
self.serial_tx = Signal()
def elaborate(self, platform):
m = Module()
cd_sync = ClockDomain(reset_less=True)
m.domains += cd_sync
m.submodules.clock = Instance("IBUFGDS",
i_I=self.clk156_p, i_IB=self.clk156_n, o_O=cd_sync.clk)
tx = uart.RS232TX(round(2**32*self.baudrate/self.clk_freq))
m.submodules.tx = tx
m.d.comb += [
tx.stb.eq(1),
tx.data.eq(ord("A")),
self.serial_tx.eq(tx.tx)
]
return m
def main():
top = Top()
output = verilog.convert(Fragment.get(top, None),
ports=(top.clk156_p, top.clk156_n, top.serial_tx))
print(output)
if __name__ == "__main__":
main()