TNETE2101

10BASE-T/100BASE-TX/100BASE-FX

LOW-POWER PHYSICAL-LAYER INTERFACE

SPWS032D – JANUARY 1997 – REVISED MARCH 1999

20

POST OFFICE BOX 655303

PHY generic status register – GEN_sts at 0x01

BIT

15

14

13

12

11

10

9876

5

4

3

2

1

BIT

0

0

1

1

1

1

Reserved

1

AUTOCMPLT

RFAULT

1

LINK

JABBER

1

Figure 8. PHY Generic Status Register

Table 7. PHY Generic Status Register Bit Functions

BIT

FUNCTION

NAME

NO.

FUNCTION

0

15

100BASE-T4 ability. Not supported.

1

14

100BASE-TX full-duplex ability. Supported by this PHY.

1

13

100BASE-TX half-duplex ability. Supported by this PHY.

1

12

10BASE-T full-duplex ability. Supported by this PHY.

1

11

10BASE-T half-duplex ability. Supported by this PHY.

Reserved

10–7

Reserved. Read and write as 0.

1

6

Management frame preamble suppression. This PHY accepts management frames with the preamble suppressed.

Management frames sent over MDIO do not need to be preceded by the preamble pattern of 32 1s.

AUTOCMPLT

5

Autoconfiguration complete. When AUTOCMPLT is read as 1, it indicates that the autonegotiation process has

completed and the values of registers AN_adv, AN_lpa, AN_exp, and AN_np are valid. If autonegotiation is in

progress, or has been restarted and AUTORSRT is still set to 1, or has been disabled by clearing AUTOENB to 0,

the AUTOCMPLT bit reads as 0.

RFAULT

4

Remote fault. The RFAULT bit is set to 1 during autonegotiation if an error in the protocol is detected and negotiation

is restarted. If the negotiation involved the exchange of multiple next pages, this bit indicates that the first of those

pages needs to be reloaded into AN_np due to the restart. RFAULT is latched as 1 until the register is read. The

default value of RFAULT is 0.

1

3

Autonegotiation ability. Supported by this PHY.

LINK

2

Link status. In general, when LINK is set to 1, the PHY is reporting that a good link is available to the link partner for

exchange of data. The value of LINK is latched until the register is read. The default value of LINK is 1.

In 10BASE-T mode, LINK is set to 1 when the PHY has determined that a valid 10BASE-T link is established. LINK

read as a 0 indicates that the link is not valid. The PHY implements the standard 10BASE-T link integrity test state

machine. To maintain a good link, link pulses are expected every 8–24 ms. If no link pulses are seen for over 100 ms,

the link invalid state is entered, and this bit is cleared. If AUTOENB is not set, then the bit is set again after seven

consecutive, correctly timed link pulses are received.

In 100BASE-TX mode, the LINK bit is set when the descrambler has locked onto the incoming data stream and has

remained locked for a minimum of 330

ms.

If AUTONEG is set, then the link is becoming invalid, which causes the autonegotiation process to restart.

JABBER

1

Jabber detect. The jabber function is not specified for 100BASE-TX PHYs, so JABBER always reads as 0 (default)

when the PHY is operating in the 100-Mbit/s mode.

When JABBER is read as 1, it indicates that a 10BASE-T jabber condition has been detected. JABBER is latched

as 1 until the register is read or PHY is reset.

The jabber condition occurs when a single packet transmission exceeds 20 ms. In the jabber condition, all transmit

requests are ignored, MCOL is asserted high, and collision detection is disabled, as is the internal loopback of

transmit data (when in half-duplex mode). The jabber condition persists for 576–628 ms after deassertion of MTXEN

before packet transmission can restart.

1

0

Extended capability. This PHY implements an extended register set.