ASIX ELECTRONICS CORPORATION

35

CONFIDENTIAL

AX88872P Swipeater Controller

PRELIMINARY

Appendix B: Design Note

B.1 Using Station Management (STA) Connection

There are two methods to get two switch port speed and duplex information in AX88872 . One way is by hardware pins

such as SPEED0, SDUPLEX0, SPEED1, SDUPLEX1. AX88872 also provides 2 pins (MDC and MDIO, STA – Station

Management connection) to read PHY Auto Negotiation Remote Capability register to get current speed and duplex

status. For the PHY connected to repeater ports must be configured by STA write function. In a word, AX88872 use STA

read function to get PHY register status for switch port and use STA write function to program PHY register for hub port.

The address setting of PHY must be fixed as follows:

Application 1: 8 hub ports + 2 switch ports application

RP : repeater port

SP : switch port

RP0

RP1

RP2

RP3

RP4

RP5

RP6

RP7

SP0

SP1

04h

05h

06h

07h

08h

09h

0ah

0bh

0fh

10h

The corresponding option setting

/RdPhy_En = 0, WrPhyNo_S = 1, WrPhyStrAddr = 1

Application 2: 6 hub ports + 2 switch ports application

RP : repeater port

SP : switch port

RP0

RP1

RP2

RP3

RP4

RP5

SP0

SP1

18h

19h

1ah

1bh

1ch

1dh

1eh

1fh

The corresponding option setting

/RdPhy_En = 0, WrPhyNo_S = 0, WrPhyStrAddr = 0