VSC8221 Evaluation Board
VPPD-03471 VSC8221 User Guide Revision 1.0
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Figure 4 • Register List Window
Verify that the device is up and running by reading MII Register 0. It should read back 0x1040. Reading
back “0000” or “FFFF” (all 0’s or all 1’s) indicates a problem.
To read or write the extended MII registers click on the ExtMII tab.
An initialization script may be used to configure multiple VSC8221 registers. The initialization script is
simply a text file which contains a list of registers to be written. Select the Device item on the top pull
down menu area and click on Load-All-Registers option. A pop-up window will appear. Navigate to and
select the desired script to be loaded.
As per Section 31.1 of the datasheet, there are a number of internal registers that must be changed
from their default value during device initialization. Use this method to initialize the device by loading
“vsc8221_workaround31_1.txt” included in the GUI package under the Script/ directory. GUI Setup
4.4
Test Cases
4.4.1
CAT5 to 802.3z Serdes with Clause 37 AutoNeg Detection
After power-up or reset, the VSC8221 will operate at CAT5 to 802.3z Serdes with clause 37 Auto
Negotiation Detection mode. An SFP loopback module enables MAC side SGMII loopback. 1G
Ethernet received by the VSC8221 RJ-45 port is routed through the VSC8221 and looped back via
SGMII through the SFP Electrical Loopback module.
Set up the copper Ethernet traffic source (e.g., IXIA or Smartbits).
Connect an Ethernet cable to an RJ-45.
Plug in a SFP loopback module.
Monitor the link-up bit in MII Register 1, bit 2 (MII 1.2), read twice to update. Traffic should now
be flowing.
