set_io --warn-no-port tx_active B1
set_io --warn-no-port tx C2
set_io --warn-no-port tx_delay C1
set_io --warn-no-port tx_inverted D2

# 16MHz clock
set_io --warn-no-port clk_16mhz B2

set_io --warn-no-port usb_pu A3