3.20. User switches and LEDs

The FPGA provides a switch and LED register that enables you to read the general-purpose push button switch and the user switches (S6) and light the user LEDs (located next to switch S6). See Figure 1.1 for the location of the switches and LEDs. Figure 3.38 shows the interface.


Switch S6-1 and S6-2 are used to control the Boot Monitor. See Boot Monitor configuration switch.

Set bits [7:0] in the SYS_LED register at 0x10000008 to illuminate LEDs 7-0. The state of the user switches S6[8:1] is present on bits [7:0] of the SYS_SW register at 0x10000004.


The state of the general-purpose push button S3 can be read from GPIO 2. See General Purpose Input/Output, GPIO. The GPIO can be programmed to generate an interrupt when the switch is pressed.

Figure 3.38. Switch and LED interface

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