12 mdio user access register 0 (useraccess0), Section 4.12 – Texas Instruments TMS320TCI6486 User Manual
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MDIO Registers
4.12 MDIO User Access Register 0 (USERACCESS0)
The MDIO user access register 0 (USERACCESS0) is shown in
and described in
Figure 39. MDIO User Access Register 0 (USERACCESS0)
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 32. MDIO User Access Register 0 (USERACCESS0) 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 writeable 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.
87
SPRUEF8F – March 2006 – Revised November 2010
C6472/TCI6486 EMAC/MDIO
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