CS61310

14

DS440F1 FEB ‘03

2.13

Control Register 1: Address 0x10

TAOS

Transmit All Ones Select

When TAOS = 1, all ones are transmitted at the TCLK frequency

LLOOP

Local Loopback

When LLOOP = 1, data input at TPOS, TNEG (TDATA) is internally looped back and output on

RPOS, RNEG (RDATA). TCLK is routed to RCLK, through the jitter attenuator, if activated.

RLOOP

Remote Loopback

When RLOOP = 1, clock and data recovered by the receiver are sent back through the transmit

path and retransmitted. The clock and data are routed through the jitter attenuator, if activated.

LBO2, 1

Line BuildOut

LBO2

LBO1

Attenuation

00

0 dB

01

-7.5 dB

10

-15 dB

1

1

-22.5 dB

CODER

Zero Substitution (valid only when TNEG (UBS) is tied high, invoking coder mode).

(TAZ)

Setting CODER to “1” enables B8ZS encoding and decoding.

When not in coder mode (TPOS/TNEG are data inputs) setting TAZ to “1” causes all zeros to

be transmitted.

NLOOP

Network Loopback

NLOOP = 1 when a network loopback code has been detected on the received signal.

An interrupt will occur when NLOOP changes state unless a “1” is written to NLOOP disabling

the interrupt.

LOS

Loss Of Signal

LOS = 1 when the loss of signal criteria have been met (175 zeros).

LOS = 0 when a valid signal is being received.

An interrupt will occur when LOS changes state unless a “1” is written to LOS disabling the in-

terrupt.

2.14

Control Register 2: Address 0x11

AIS

Alarm Indication Signal.

AIS = 1 when an all ones pattern is present at the receiver. This bit is reset to “0” by the first

read occurring after the AIS condition has cleared.

An interrupt will occur when AIS is present unless a “1” is written to AIS disabling the interrupt.

RAMPLSE

When RAMPLSE = 1, output pulse shapes are determined by the codes in the internal, pro-

grammable, transmit RAM.

LOOPDN

Loop Down

Setting LOOPDN to “1” causes the data pattern 001... to be repetitively transmitted.

7 (MSB)

6543

21

0 (LSB)

TAOS

LLOOP

RLOOP

LBO2

LBO1

CODER

TAZ

NLOOP

LOS

7(MSB)

6

5

4

3

2

1

0(LSB)

AIS

RAMPLSE

RSVD

set to “0”

LOOPDN

LOOPUP

RPWDN

TxHIZ

RSVD

set to “0”