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14 mdio user access register 1 (useraccess1), Section 4.14 – Texas Instruments TMS320TCI6486 User Manual

Page 89

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MDIO Registers

4.14 MDIO User Access Register 1 (USERACCESS1)

The MDIO user access register 1 (USERACCESS1) is shown in

Figure 41

and described in

Table 34

.

Figure 41. MDIO User Access Register 1 (USERACCESS1)

31

30

29

28

26

25

21

20

16

GO

WRITE

ACK

Reserved

REGADR

PHYADR

R/WS-0

R/W-0

R/W-0

R-0

R/W-0

R/W-0

15

0

DATA

R/W-0

LEGEND: R = Read only; R/W = Read/Write; R/WS = Read/Write 1 to set; -n = value after reset

Table 34. MDIO User Access Register 1 (USERACCESS1) Field Descriptions

Bit

Field

Value

Description

31

GO

Go bit. Writing a 1 to this bit causes the MDIO state machine to perform an MDIO access when it is
convenient for it to do so, this is not an instantaneous process. Writing a 0 to this bit has no effect.
This bit is write-able only if the MDIO state machine is enabled. This bit will self clear when the
requested access has been completed. Any writes to the USERACCESS0 register are blocked
when the go bit is 1.

30

WRITE

Write enable bit. Setting this bit to a 1 causes the MDIO transaction to be a register write, otherwise
it is a register read.

0

The user command is a read operation

1

The user command is a write operation

29

ACK

Acknowledge bit. This bit is set if the PHY acknowledged the read transaction.

28-26

Reserved

0

Reserved

25-21

REGADR

Register address bits. This field specifies the PHY register to be accessed for this transaction.

20-16

PHYADR

PHY address bits. This field specifies the PHY to be accessed for this transaction.

15-0

DATA

User data bits. These bits specify the data value read from or to be written to the specified PHY
register.

89

SPRUEF8F – March 2006 – Revised November 2010

C6472/TCI6486 EMAC/MDIO

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