Lucent Technologies Inc.

21

Data Sheet

LU6612

July 2000

FASTCAT Single-FET for 10Base-T/100Base-TX

Table 18. MR29—Device-Specific Register 2 (100 Mbits/s Control) Bit Descriptions

1. Note that the format for the pin descriptions is as follows: the first number is the register number, the second number is the bit position in the

register, and the name of the instantiated pad is in capital letters.

2. R = read, W = write.

Description

29.15 (LOCALRST)

R/W

Management Reset. This is the local management reset bit. Writing a logic 1 to

this bit will cause the lower 16 registers and registers 28 and 29 to be reset to

their default values. This bit is self-clearing. The default is 0.

29.14 (RST1)

R/W

Generic Reset 1. This register is used for manufacture test only. The default is 0.

29.13 (RST2)

R/W

Generic Reset 2. This register is used for manufacture test only. The default is 0.

29.12 (100OFF)

R/W

100 Mbits/s Transmitter Off. When this bit is set to 0, it forces RX low and RY

high. This bit defaults to 1.

29.11

R/W

Reserved. Program to zero.

29.10 (CRS_SEL)

R/W

Carrier Sense Select. CRS will be asserted on receive only when this bit is set to

a 1. If this bit is set to logic 0, CRS will be asserted on receive or transmit. The

default is 0.

29.9 (LINK_ERR)

R/W

Link Error Indication. When this bit is a 1, a link error code will be reported on

RXD[3:0] of the LU6612 when RX_ER is asserted on the MII. The specific error

codes are listed in the RXD pin description. If it is 0, it will disable this function.

The default is 0.

29.8 (PKT_ERR)

R/W

Packet Error Indication Enable. When this bit is a 1, a packet error code, which

indicates that the scrambler is not locked, will be reported on RXD[3:0] of the

LU6612 when RX_ER is asserted on the MII. When this bit is 0, it will disable this

function. The default is 0.

29.7 (RESERVED)

R/W

Reserved. This bit must remain as a zero. The default is 0.

29.6 (EDB)

R/W

Encoder/Decoder Bypass. When this bit is set to 1, the 4B/5B encoder and

5B/4B decoder function will be disabled. The default is a zero. At powerup/reset, if

PCSEN

is strapped low, then this bit is set to a 1. The default is 0.

29.5 (SAB)

R/W

Symbol Aligner Bypass. When this bit is set to 1, the aligner function will be dis-

abled. The default is 0.

29.4 (SDB)

R/W

Scrambler/Descrambler Bypass. When this bit is set to 1, the scrambling/

descrambling functions will be disabled. The default is a zero. At powerup/reset, if

PCSEN

is strapped low, then this bit is set to a 1. The default is 0.

29.3 (CARIN_EN)

R/W

Carrier Integrity Enable. When this bit is set to a 1, carrier integrity is enabled.

(This function is not supported by QS6611.) The default is 0.

29.2 (JAM_COL)

R/W

Jam Enable. When this bit is a 1, it enables JAM associated with carrier integrity

to be ORed with COL. The default is 0.

29.1 (RESERVED)

R/W

Reserved. This bit must remain as a zero. The default is 0.

29.0 (RESERVED)

R/W

Reserved. This bit must remain as a zero. The default is 0.