The LatticeECP3 doesn't have a dedicated control signal to put the FPGA IO to tri-state. There are cases that some designers might want to have the LatticeECP3 FPGA IO tri-stated when a new line card is being inserted as some partner devices in these line-cards might not support hot swap. The solution is that the designer can force a temporary pull-down the PROGRAMN pin to achieve tri-state IOs, and then later the LatticeECP3 can be re-activated (via reconfiguration) after the line-card is reliably inserted and stabilized in the system.