VSC8641XKO Vitesse Semiconductor Corp, VSC8641XKO Datasheet - Page 24

• Manufacturer Part Number: VSC8641XKO
• Description: IC PHY 10/100/1000 100-LQFP
• Manufacturer: Vitesse Semiconductor Corp
• Type: PHY Transceiverr

Specifications of VSC8641XKO

• Number Of Drivers/receivers: 1/1
• Protocol: Gigabit Ethernet
• Voltage - Supply: 2.5V, 3.3V
• Mounting Type: Surface Mount
• Package / Case: 100-LQFP
• Case: TQFP
• Dc: 07+
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 907-1031

3.5
3.6
Revision 4.3
August 2009
Manual MDI/MDI-X Setting
As an alternative to automatic MDI/MDI-X detection (using HP Auto-MDIX technology),
you can force the PHY to select MDI or MDI-X using the following scripts.
Format:
Phywrite ( register(dec), data(hex) )
Phywritemask ( register(dec), data(hex), mask(hex) )
To force MDI:
Phywrite ( 31, 0x2A30 )
Phywritemask ( 5, 0x0010, 0x0018 )
Phywrite ( 31, 0x0000 )
To force MDI-X:
Phywrite ( 31, 0x2A30 )
Phywritemask ( 5, 0x0018, 0x0018 )
Phywrite ( 31, 0x0000 )
To resume MDI/MDI-X setting based on register 18, bits 7 and 5:
Phywrite ( 31, 0x2A30 )
Phywritemask ( 5, 0x0000, 0x0018 )
Phywrite ( 31, 0x0000 )
Automatic Crossover and Polarity Detection
For trouble-free configuration and management of Ethernet links, the VSC8641 device
includes a robust, automatic, media-dependent and crossed media-dependent
detection feature, HP Auto-MDIX, in all of its three available speeds (10BASE-T,
100BASE-T, and 1000BASE-T). The function is fully compliant with clause 40 of the
IEEE standard 802.3-2002.
Additionally, the device detects and corrects polarity errors on all MDI pairs—a useful
capability that exceeds the requirements of the standard.
Both HP Auto-MDIX detection and polarity correction are enabled in the device by
default. The default settings are adjustable using device register bits 18.5:4. Status
bits for each of these functions are located in register 28.
Functional Descriptions
VSC8641 Datasheet
Page 24