EB-GS2985-S
Evaluation Board User Guide
52246 - 2
July 2009
19 of 25
Pin Override Functionality
1.9.5 Start-up Process
1. Ensure the software and drivers are installed on your PC.
2. Connect the Gennum USB Dongle Board to the EB-GS2985-S using the supplied
ribbon cable as per
Figure 1-11
.
3. Connect the power supplies as per
Section 1.7
and power up the board.
4. Connect the Gennum USB Dongle Board to a PC USB port via a USB cable.
5. Perform a hard reset, via the Reset button on the Gennum USB Dongle board as per
Figure 1-10
.
6. Launch the GS2985 Control Software on the PC connected to the Gennum USB
Dongle Board.
7. The GS2985 registers can now be controlled through the SPI.
1.10 Optional Connectors
The EB-GS2985-S board also features footprints for two optional test points (SQ_ADJ
and XTAL_BUF_OUT).
DATA/CLOCK
Sets the DDO1 output.
checked = DATA, unchecked = CLOCK
DDO1 DISABLE
Disables DDO1
DATA_MUTE
Mutes all DATA outputs
AUTOBYPASS
Sets the reclocker in autobypass mode
BYPASS
Sets the reclocker in bypass mode
MANUAL
checked = manual data rate selection,
unchecked = auto data rate detection
KBB
Sets KBB to one of three settings (GND,
Floating, VCC)
