LEDs and Pushbuttons
There are eight LEDs and four pushbuttons on the XEM6001. Each is wired directly to the FPGA as shown in the tables below.
| LED | FPGA PIN |
|---|---|
| D1 | A4 |
| D2 | C5 |
| D3 | B5 |
| D4 | A5 |
| D5 | C6 |
| D6 | B6 |
| D7 | A6 |
| D8 | A7 |
| BUTTON | FPGA PIN |
|---|---|
| BTN1 | D5 |
| BTN2 | D6 |
| BTN3 | D8 |
| BTN4 | D9 |
The LED anodes are connected to a pull-up resistor to +3.3VDD and the cathodes wired directly to the FPGA. To turn ON an LED, the FPGA pin should be brought low. To turn OFF an LED, the FPGA pin should be brought high.
The pushbuttons are connected between their respective FPGA pin and DGND. The FPGA side of the connection has a pull-up resistor to +3.3VDD. Therefore, in the pressed state, the FPGA pin will be at DGND (low) and in the unpressed state, the FPGA pin will be at +3.3VDD (high). Note that the pushbuttons are not debounced on the XEM6001. In order to deglitch the signals from the pushbuttons, proper debouncing should be done inside the FPGA.