TNETE2101

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

LOW-POWER PHYSICAL-LAYER INTERFACE

SPWS032D – JANUARY 1997 – REVISED MARCH 1999

24

POST OFFICE BOX 655303

message-page encoding (LPMP = 1)

BIT

15

14

13

12

11

10

987654321

BIT

0

LPNP

ACK

LPMP

ACK2

T

Message Code Field

Figure 13. Message-Page-Encoding Register

Table 10. Message-Page-Encoding Register Bit Functions

BIT

FUNCTION

NAME

NO.

FUNCTION

LPNP

15

Link partner next page. When LPNP is set to 1, the link partner is ready to exchange an extra next page.

See the description of NP in register AN_adv for more information on next-page exchange.

ACK

14

Acknowledge. Reserved for internal use of the autonegotiation process. Ignore during read.

LPMP

13

Link partner message page. When LPMP is set to 1, register AN_lpa contains a message page.

ACK2

12

Acknowledge 2. Reserved for internal use of the autonegotiation process. Ignore during read.

T

11

Toggle. Reserved for internal use of the autonegotiation process. Ignore during read.

Message Code Field

10–0

Message code. An 11-bit message code. See Table 11 for descriptions of the currently defined IEEE

message codes.

message-code field values

Table 11 summarizes the message-code field values specified in IEEE Std 802.3. All message codes not

specified are reserved for future IEEE use or allocation.

Table 11. Message-Code Field Values

MESSAGE

CODE

BIT 10–0

MESSAGE-CODE DESCRIPTION

0

00000000000

Reserved for future autonegotiation use

1

00000000001

Null message. The null-message code is transmitted during next-page exchange when the local device has

no further messages to transmit and the link partner is still transmitting valid next pages.

2

00000000010

Technology ability extension code 1 [one unformatted page (UP) with technology ability field to follow]. This

message code is reserved for future expansion of the technology ability field and indicates that a defined user

code with a specific technology ability field encoding follows.

3

00000000011

Technology ability extension code 2 (two UPs with technology ability fields to follow). This message code is

reserved for future expansion of the technology ability field and indicates that two defined user codes with

specific technology ability field encoding follow.

4

00000000100

Remote-fault number code (one UP with binary-coded remote fault follows). This message code is followed

by a single user code whose encoding specifies the type of fault that has occurred. The following user codes

are defined:

0 – RF test. Used to test remote-fault operation.

1 – Link loss

2 – Jabber

3 – Parallel detection fault. Sent to identify when PDFAULT (in AN_exp) is set.