There are four LEDs on the ZEM5310 in addition to the power LED.  Each is wired directly to the FPGA as shown in the table below.

LEDFPGA PIN
D1D9
D2A12
D3B13
D4G17

The LED anodes are connected to a pull-up resistor to +2.5 V and the cathodes wired directly to the FPGA on Bank 7A and 8A with a bank I/O voltage of 1.5 V.  To turn ON an LED, the FPGA pin should be at logic ‘0’.  To turn OFF an LED, the FPGA pin should be set to high impedance (tri-stated).