High Performance Two Port 10/100 Managed Ethernet Switch with 32-Bit Non-PCI CPU Interface

Datasheet

14.4Ethernet PHY Control and Status Registers

This section details the various LAN9312 Ethernet PHY control and status registers. The LAN9312 contains three PHY’s: Port 1 PHY, Port 2 PHY and a Virtual PHY. All PHY registers follow the IEEE

802.3(clause 22.2.4) specified MII management register set. All functionality and bit definitions comply with these standards. The IEEE 802.3 specified register index (in decimal) is included with each register definition, allowing for addressing of these registers via the MII serial management protocol. For additional information on the MII management protocol, refer to the IEEE 802.3 Specification.

Each individual PHY is assigned a unique PHY address as detailed in Section 7.1.1, "PHY Addressing," on page 82.

14.4.1Virtual PHY Registers

The Virtual PHY provides a basic MII management interface for communication with the Host MAC for connection to the Host as if it was attached to a single port PHY. The Virtual PHY registers differ from the Port 1 & 2 PHY registers in that they are addressable via the memory map, as described in Table 14.1, as well as serially. These modes of access are described in Section 14.2.8, "Virtual PHY," on page 245.

Because the Virtual PHY registers are also memory mapped, their definitions have been included in the System Control and Status Registers Section 14.2.8, "Virtual PHY," on page 245. A list of the Virtual PHY MII addressable registers and their corresponding register index numbers is also included in Table 14.4.

Note: When serially accessed, the Virtual PHY registers are only 16-bits wide, as is standard for MII management of PHY’s.

14.4.2Port 1 & 2 PHY Registers

The Port 1 and Port 2 PHY’s are comparable in functionality and have an identical set of non-memory mapped registers. The Port 1 and Port 2 PHY registers are not memory mapped. These registers are indirectly accessed through the Host MAC MII Access Register (HMAC_MII_ACC) and Host MAC MII Data Register (HMAC_MII_DATA) registers in the Host MAC via the MII serial management protocol specified in IEEE 802.3 clause 22. Because the Port 1 & 2 PHY registers are functionally identical, their register descriptions have been consolidated. A lowercase “x” has been appended to the end of each PHY register name in this section, where “x” should be replaced with “1” or “2” for the Port 1 PHY or the Port 2 PHY registers respectively. A list of the Port 1 & 2 PHY MII addressable registers and their corresponding register index numbers is included in Table 14.7. Each individual PHY is assigned a unique PHY address as detailed in Section 7.1.1, "PHY Addressing," on page 82.

Table 14.7 Port 1 & 2 PHY MII Serially Adressable Registers

INDEX #

SYMBOL

REGISTER NAME

 

 

 

0

PHY_BASIC_CONTROL_x

Port x PHY Basic Control Register, Section 14.4.2.1

 

 

 

1

PHY_BASIC_STATUS_x

Port x PHY Basic Status Register, Section 14.4.2.2

 

 

 

2

PHY_ID_MSB_x

Port x PHY Identification MSB Register, Section 14.4.2.3

 

 

 

3

PHY_ID_LSB_x

Port x PHY Identification LSB Register, Section 14.4.2.4

 

 

 

4

PHY_AN_ADV_x

Port x PHY Auto-Negotiation Advertisement Register,

 

 

Section 14.4.2.5

 

 

 

5

PHY_AN_LP_BASE_ABILITY_x

Port x PHY Auto-Negotiation Link Partner Base Page Ability

 

 

Register, Section 14.4.2.6

 

 

 

6

PHY_AN_EXP_x

Port x PHY Auto-Negotiation Expansion Register,

 

 

Section 14.4.2.7

 

 

 

SMSC LAN9312

285

Revision 1.4 (08-19-08)

 

DATASHEET