Datasheet

Table Of Contents
MDC
TA
Register Data
Z
Z
Z Z Z
0 0 0 00 00 00 00 0 00 00 00 00 0 00 01 1 1 11 1 1
Idle
Z
Z
MDIO
(STA)
MDIO
(PHY)
Idle Start
Opcode
(Read)
PHY Address
(PHYAD = 0Ch)
Register Address
(00h = BMCR)
MDC
ZZ
MDIO
(STA)
TA
Register Data
Z
Z
0 1 0 00 00 00 00 0 00 01 00 00 0 0 00 01 1 0 00 1 0
Idle
Idle
Start
Opcode
(Read)
PHY Address
(PHYAD = 0Ch)
Register Address
(00h = BMCR)
TLK100
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SLLS931BAUGUST 2009REVISED DECEMBER 2009
For write transactions, the station-management entity writes data to the addressed TLK100, thus
eliminating the requirement for MDIO Turnaround. The Turnaround time is filled by the management entity
by inserting <10>. Figure 4-3 shows the timing relationship for a typical MII register write access. The
frame structure and general read/write transactions are shown in Table 4-1, Figure 4-2, and Figure 4-3.
Table 4-1. Typical MDIO Frame Format
MII Management Serial Protocol <idle><start><op code><device addr><reg addr><turnaround><data><idle>
Read Operation <idle><01><10><AAAAA><RRRRR><Z0><xxxx xxxx xxxx xxxx><idle>
Write Operation <idle><01><01><AAAAA><RRRRR><10><xxxx xxxx xxxx xxxx><idle>
Figure 4-2. Typical MDC/MDIO Read Operation
Figure 4-3. Typical MDC/MDIO Write Operation
4.2.1 Extended Address Space Access
The TLK100 SMI function supports read/write access to the extended register set using registers
REGCR(0x000Dh) and ADDAR(0x000Eh) and the MDIO Manageable Device (MMD) indirect method
defined in IEEE802.3ah Draft for clause 22 for accessing the clause 45 extended register set.
Accessing the standard register set, i.e. MDIO registers 0 to 31, can be performed using the normal direct
MDIO access or the indirect method, except for register REGCR(0x000Dh) and ADDAR(0x000Eh) which
can be accessed only using the normal MDIO transaction. The SMI function will ignore indirect accesses
to these registers.
REGCR(0x000Dh) is the MDIO Manageable MMD access control. In general, register REGCR(4:0) is the
device address DEVAD that directs any accesses of ADDAR(0x000Eh) register to the appropriate MMD.
Specifically, the TLK100 uses the vendor specific DEVAD[4:0] = "11111" for accesses. All accesses
through registers REGCR and ADDAR should use this DEVAD. Transactions with other DEVAD are
ignored. REGCR[15:14] holds the access function: address (00), data with no post increment (01), data
with post increment on read and writes (10) and data with post increment on writes only (11).
Copyright © 2009, Texas Instruments Incorporated Interfaces 23
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