Alchitry Io Switches with Au

[garthberry]

After trying to get the switches (DIP and pushbutton) Alchitry Io working for a little too long it finally occurred to me that pulldowns need to be enabled for each of the pins attached to a switch. If pulldowns are not enabled the pin will typically float high. The pulldown resistor can be enabled on a pin by pin basis in the  constraints file as follows:

Code:

set_property PACKAGE_PIN C4 [get_ports {dip_sw[0]}]
set_property IOSTANDARD LVCMOS33 [get_ports {dip_sw[0]}]
set_property PULLDOWN TRUE [get_ports {dip_sw[0]}]