VSC8641XKO Vitesse Semiconductor Corp, VSC8641XKO Datasheet - Page 123

• 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

8.10
Revision 4.3
August 2009
| -- Logical OR
= -- Assign value to variable
PHY_Write (PortNo, 31, 0x52b5);
PHY_Write (PortNo, 16, 0xa7fa); // Necessary write of internal register
reg = PHY_Read (PortNo, 18); // Read internal register and assign it to
var.
PHY_Write (PortNo, 18, reg); // Necessary write of internal register
reg = PHY_Read (PortNo, 17); // Read internal register and assign it to
var.
reg = (reg | 0x0008); // Modify variable value
PHY_Write (PortNo, 17, reg); // Write back modified internal register
PHY_Write (PortNo, 16, 0x87fa) // Necessary write of internal register
PHY_Write (PortNo, 31, 0x0000); // Select main register page
High VDD33 and Low VDDIOMAC Supply
Issue: If VDD33 is set to the maximum allowed 3.3 V supply and VDDIOMAC is set to
the minimum allowed 3.3 V supply, the VSC8641 device can experience performance
issues. This issue generally occurs in a lab environment and not in typical applications.
Implications: When VDDIOMAC is set to 3.3 V, VDD33 and VDDIOMAC cannot be
sourced by two different 3.3 V supplies.
Workaround: If using VDDIOMAC in 3.3 V mode, use the same 3.3 V source supply as
the VDD33, using a proper filtering scheme. For more information, see VSC8641 Design
and Layout Guide, which is available on the Vitesse Web site at www.vitesse.com.
// Select internal register page
Design Considerations
VSC8641 Datasheet
Page 123