JTAG and/or IO pin usage

You can connect the pin which drives the JTAG pins to other IO if you're careful, but you can't reuse the pins themselves.

The safest way is to share TCK with another clock, and tie TMS high when not in JTAG mode. The MAX will then ignore TDI and tristate TDO.

An alternative is to tie TCK either high or low, while using other pins as IO. The MAX will ignore TDI and will probably tristate TDO, but if you get noise on TCK then it could get into a state where it drives TDO.