VSC8221 Evaluation Board
VPPD-03471 VSC8221 User Guide Revision 1.0
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3.1.6
External RefClk Option
The user may choose to provide an external PHY REFCLK via the SMA connector (J11). The user must
configure the device by installing a jumper on J24 in the PLL disable or ground (left) position and
installing a jumper on J12 in the SMA (right) position.
3.1.7
Silabs Microcontroller
A Silabs F340 microcontroller is included to facilitate a software interface to the registers on the
VSC8221 through a USB port.
3.1.8
EEPROM Option
The user may choose to configure theVSC8221 via an EEPROM load. In order to program the EEPROM
properly, pull-up or pull-down resistors must be configured for either R7 – R9 or R15 – R17. See Section
19 of the datasheet regarding to EEPROM programming requirement.
3.1.9
CMODE Pins
On the lower center of the board, there is an option to change the CMODE pin pull-up or pull-down
resistors, R6, R12 – R14, and R18 – R21. See Section 18 of the datasheet for the detail on how to
program the desired operating condition parameters through the CMODE configuration bits and how to
choose the value of each CMODE pull-up or pull-down resistor.
3.1.10
CLOCKOUT SMA
The user should observe a 125MHz output clock through this SMA if the internal PHY PLL is operating
properly.
3.2
Software Requirements
The VSC8221 GUI can be loaded on to any PC or laptop that complies with the following requirements:
The PC must run a recent version of MS-Windows. According to the Microsoft website, the following
operating systems can run .NET based applications:
Windows 2000
Windows XP
Windows Vista
Windows-7
Note: The GUI may be slower when run on Windows 2000 operating system.
Hardware requirements must be considered when deploying/installing .NET applications. The
minimum hardware requirement for a system running a .NET application is a Pentium 90MHz with
32 MB of RAM. For best performance, a newer system is recommended along with a minimum of 1
GB of RAM.
If the .NET Framework 2.0 is not already installed, it may be obtained from the following link:
http://www.microsoft.com/downloads/details.aspx?FamilyID=0856EACB-4362-4B0D-8EDD-
AAB15C5E04F5&displaylang=en
