DS2149

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Table 9-B. Control and Operation Mode Selection

MODE1 MODE0 HARDWARE SOFTWARE NRZ BIPOLAR AMI B8ZS

OUTPUTS

DISABLED

Low

Low

On

Off

Off

On

Off

Off

No

Low

High

On

Off

Off

On

Off

Off

Yes

Low

Open

On

Off

On

Off

On

Off

No

High

Low

Off

On

X

X

X

X

No

High

High

Off

On

X

X

X

X

Yes

High

Open

Off

On

X

X

X

X

No

Open

Low

On

Off

On

Off

Off

On

No

Open

High

On

Off

On

Off

Off

On

Yes

Open

Open

On

Off

On

Off

Off

On

No

10. DIAGNOSTIC MODE OPERATION

The DS2149 offers several diagnostic modes as listed in Table 10-A. Various diagnostic modes are only

available in software mode. In hardware mode, the diagnostic modes are selected by a combination of pin

settings. In software mode, the diagnostic modes are selected by setting appropriate bits in the diagnostic

control register.

Table 10-A. Diagnostic Modes

AVAILABILITY

SOFTWARE MODE

DIAGNOSTIC MODE

HARDWARE

SOFTWARE

MASKABLE

Local Loopback (LLB)

Yes

Yes

No

Analog Loopback (ALB)

Yes

Yes

No

Remote Loopback (RLB)

Yes

Yes

No

In-Band Network Loopback (NLB)

Yes

Yes

Yes

Dual Loopback (DLOOP)

Yes

Yes

No

Internal Data Pattern Generation and Detection

Transmit AIS (TAIS)

Yes

Yes

No

Quasirandom Signal Source (QRSS)

Yes

Yes

Yes

In-Band Loop-Up/Down Code Generator

No

Yes

No

Error Insertion and Detection

Bipolar Violation Insertion (INSBPV)

Yes

Yes

No

Logic Error Insertion (INSLER)

Yes

Yes

No

Bipolar Violation Detection (BPV)

Yes

Yes

No

Logic Error Detection, QRSS (QPD)

Yes

Yes

No

Alarm Condition Monitoring

Receive Carrier Loss (RCL) Monitoring

Yes

Yes

Yes

Receive Alarm Indication Signal (AIS) Monitoring

No

Yes

Yes

Transmit Driver Failure Monitoring (DFMO)

No

Yes

Yes

Jitter Attenuator Limit Trip (JALT)

No

Yes

Yes

Other Diagnostic Reports

Receive Line Attenuation Indicator (LATN)

No

Yes

No