There are eight general-purpose LEDs on the ECM1900. Each is wired to the FPGA (bank 66) as shown in the table below.
|LED REF DES||FPGA PIN|
LED Operation in HDL
The LED anodes are connected to a pull-up resistor to +3.3 V, and the cathodes wired through NMOS transistors to the FPGA I/O on Bank 66.
To operate the LEDs from FPGA gateware (HDL):
- To turn ON an LED, the corresponding FPGA pin should be at logic
- To turn OFF an LED, the corresponding FPGA pin should be at logic