5.
The
EMACMIIDATA
register should be written with the address of the extended register to be
accessed. This value is written to the
EPHYADDAR
register.
6.
Initiate write by writing the
EMACMIIADDR
register fields:
■
PLA
: Physical Layer Address of the PHY. The integrated PHY's address is 0x0.
■
MII
: Address of the PHY register to be written. In this case, it should be the address of the
EPHYADDAR
register, 0xE.
■
CR
: Clock Reference for the MDIO interface.
■
MIIW
: Write Initiation. This bit is set to 1 to indicate that a write operation is to be executed.
■
MIIB
: MII Busy. This bit is set to 1 to indicate that the MII is now busy with a write operation.
The EMAC clears this bit when the write has been transmitted.
7.
Check the
MIIB
bit in the
EMACMIIADDR
register to identify if the MII interface is busy. When
the
MIIB
bit is 0, the MII interface is available to write to the PHY registers.
8.
The
EMACMIIDATA
register should be written with the value to be passed into the
EPHYREGCTL
register. The
DEVAD
field of the
EPHYREGCTL
register identifies the device
address, which is 0x1F, for the integrated PHY. The
FUNC
field of the
EPHYREGCTL
register
should be set to 0x1 to indicate a write to an extended register address with no increment.
9.
Initiate write by writing the
EMACMIIADDR
register fields:
■
PLA
: Physical Layer Address of the PHY. The integrated PHY's address is 0x0.
■
MII
: Address of the PHY register to be written. In this case, it should be the address of the
EPHYADDAR
register, 0xD.
■
CR
: Clock Reference for the MDIO interface.
■
MIIW
: Write Initiation. This bit is set to 1 to indicate that a write operation is to be executed.
■
MIIB
: MII Busy. This bit is set to 1 to indicate that the MII is now busy with a write operation.
The EMAC clears this bit when the write has been transmitted.
10.
Check the
MIIB
bit in the
EMACMIIADDR
register to identify if the MII interface is busy. When
the
MIIB
bit is 0, the MII interface is available to write to the PHY registers.
11.
The
EMACMIIDATA
register should be programmed with the data to be written to the
EPHYADDAR
register which is transferred to the previously selected extended PHY register.
12.
Initiate write by writing the
EMACMIIADDR
register fields:
■
PLA
: Physical Layer Address of the PHY. The integrated PHY's address is 0x0.
■
MII
: Address of the PHY register to be written. In this case, it should be the address of the
EPHYADDAR
register, 0xD.
■
CR
: Clock Reference for the MDIO interface.
■
MIIW
: Write Initiation. This bit is set to 1 to indicate that a write operation is to be executed.
June 18, 2014
1462
Texas Instruments-Production Data
Ethernet Controller