DIP Switch

On-board 4xDIP switch S1 used for system and user settings.
Switch 1 (S1A) is used to connect the USB controller to the I²C serial EEPROM. When S1A is "ON", serial I²C EEPROM is connected to the USB controller, when switch is "OFF", the USB controller is disconnected from the EEPROMZero-resistor R90 (not populated by default) short this switch and connect EEPROM regardless of S1A position.. Turn S1A off when programming the USB EEPROM (storing the USB vendor ID and device ID). This will force the USB controller to provide its default vendor ID and device ID.
Switch 2 (S1B) is used to control DC-DC converters. When switch is "OFF", converters are controlled by the USB controller. When switch is "ON", converters are enabled regardless of USB controller actions. At start-up, the USB controller switches off 1.2V, 1.5V and 2.5V power rails and starts up the module in low-power mode. After enumeration, the USB controller firmware switches the 1.2V, 1.5V and 2.5V power rails on, if enough current is available from the USB bus.
Switches 3 (S1C) and 4 (S1D) can be used as user switches. Switches are active-low. Pull-up resistors should be defined in user constrains file (UCF) to use this switches in FPGA design. See Table 11 for details.

Table 11: DIP switch pin-out