xilinx/xc7/tests/ps7/counter_emio/zybo.xdc

set_property LOC K17 [get_ports {clk}]
set_property IOSTANDARD LVCMOS33 [get_ports {clk}]

set_property LOC M14 [get_ports {led[0]}]
set_property LOC M15 [get_ports {led[1]}]
set_property LOC G14 [get_ports {led[2]}]
set_property LOC D18 [get_ports {led[3]}]

set_property IOSTANDARD LVCMOS33 [get_ports {led[0]}]
set_property IOSTANDARD LVCMOS33 [get_ports {led[1]}]
set_property IOSTANDARD LVCMOS33 [get_ports {led[2]}]
set_property IOSTANDARD LVCMOS33 [get_ports {led[3]}]