SMSC LAN9311 User Manual

Two Port 10/100 Managed Ethernet Switch with 16-Bit Non-PCI CPU Interface

Revision 1.4 (08-19-08)

98

SMSC LAN9311/LAN9311i

 

. The speed and duplex bits in the 

 should be ignored when auto-negotiation is enabled.

The Virtual PHY supports pause flow control per the IEEE 802.3 specification. The Virtual PHYs
advertised pause flow control abilities are set via bits 10 (Symmetric Pause) and 11 (Asymmetric
Pause) of the 

. This allows the

Virtual PHY to advertise its flow control abilities and auto-negotiate the flow control settings with the
emulated link partner. The default values of these bits are as shown in 

. 

The symmetric/asymmetric pause ability of the emulated link partner is based upon the advertised
pause flow control abilities of the Virtual PHY in (bits 10 & 11) of the 

. Thus, the emulated link partner always accommodates the

asymmetric/symmetric pause ability settings requested by the Virtual PHY, as shown in 

The pause flow control settings may also be manually set via the 

. This register allows the switch fabric port 0 flow control settings

to be manually set when auto-negotiation is disabled or the Manual Flow Control Select bit 0 is set.
The currently enabled duplex and flow control settings can also be monitored via this register. The flow
control values in the 

affected by the values of the manual flow control register. Refer to 

 for additional information.

In addition to the chip-level hardware reset (nRST) and Power-On Reset (POR), the Virtual PHY
supports three block specific resets. These are is discussed in the following sections. For detailed
information on all LAN9311/LAN9311i resets, refer to 

The Virtual PHY can be reset via the 

 by setting bit 3

(VPHY_RST). This bit is self clearing after approximately 102uS.

The Virtual PHY can also be reset by setting bit 15 (VPHY_RST) of the 

. This bit is self clearing and will return to 0 after the reset is complete.

The Virtual PHY can be reset via the 

 by setting bit

10 (VPHY_RST). This bit is self clearing after approximately 102uS.