PATHDocumentation > Hardware > Power Mac G4 Cube Developer Note

     

Optional Gigabit Ethernet Port

The optional Gigabit Ethernet port supports 10Base-T, 100Base-T, and 1000Base-T transfer rates. In operation, the actual speed of the link is auto-negotiated between the computer's PHY device and the network bridge or router to which it is connected.

The connector for the Gigabit Ethernet port is an RJ-45 connector on the back of the computer. Table 3-4 shows the signals and pin assignments for 10Base-T and 100Base-T operation. Table 3-5 shows the signals and pin assignments for 1000Base-T operation.

Table 3-4   Signals for 10Base-T and 100Base-T operation

Pin

Signal name

Signal definition

1 TXP Transmit (positive lead)
2 TXN Transmit (negative lead)
3 RXP Receive (positive lead)
4 - Not used
5 - Not used
6 RXN Receive (negative lead)
7 - Not used
8 - Not used

 

Table 3-5 Signals for 1000Base-T operation

Pin

Signal name

Signal definition

1 TRD+(0) Transmit and receive data 0 (positive lead)
2 TRD-(0) Transmit and receive data 0 (negative lead)
3 TRD+(1) Transmit and receive data 1 (positive lead)
4 TRD+(2) Transmit and receive data 2 (positive lead)
5 TRD-(2) Transmit and receive data 2 (negative lead)
6 TRD-(1) Transmit and receive data 1 (negative lead)
7 TRD+(3) Transmit and receive data 3 (positive lead)
8 TRD-(3) Transmit and receive data 3 (negative lead)

To interconnect two computers for 1000Base-T operation, you must use 4-pair cable (Category 5 or 6).

The Gigabit Ethernet interface in the Power Mac G4 Cube conforms to the ISO/IEC 802.3 specification, where applicable, and complies with IEEE specifications 802.3i (10Base-T), 802.3u-1995 (100Base-T), and 802.3ab (1000Base-T).


© 2000 Apple Computer, Inc. (Last Updated 04 Oct 00)