CX28344 Conexant, CX28344 Datasheet - Page 68

• Manufacturer Part Number: CX28344
• Description: (CX2834x) Dual / Triple / Quad / Hex / Octal - Enhanced DS3 / E3 Framer
• Manufacturer: Conexant

Functional Description
2.1.2.4
2-22
E3-G.832 Mode
In E3-G.832 mode, three alarms are generated: Remote Defect Indicator (RDI),
Remote Error Indicator (REI), and Alarm Indication Signal (AIS).
RDI
Bit 1 of MA field at E3-G.832 34.368 Mbps frame structure is used to transmit RDI.
Transmission of RDI in E3-G.832 mode is similar to RAI in E3-G.751 mode. Each of
the framers has an option to insert the RDI-bit:
!
!
!
!
If automatic RDI is enabled (by setting bit AutoRAI in Transmit Overhead Insertion 1
Control register to 1), as long as LOS or OOF conditions are detected at the receiver,
the transmitter automatically inserts 1 at the transmitted RDI-bit. When LOS and
OOF conditions are no longer detected, the transmitter sets the transmitted RDI-bit to
0 (no RDI alarm). In the automatic RDI mode the transmitter side sends automatic
RDI as long as OOFAlm or LOSAlm bits at the Maintenance Status register are set.
Forcing a RDI alarm can also be done by setting TxAlm [1] to 1. As long as TxAlm
[1] is set to 1, RDI-bit contains 1, regardless of other RDI-bits sourcing settings.
REI
REI is transmitted in bit 2 of MA octet at the E3-G.832 34.386 Kb frame structure.
For each framer this bit can be either externally supplied (with the data stream or from
an external pin) or internally generated automatically.
If the REI-bit is selected to be generated internally, the transmitter sets this bit to 1
(generate REI signal) if one or more errors are detected by BIP-8 code received in the
EM field. The REI-bit is otherwise transmitted as 0 (no BIP-8 errors). During receiver
LOS or AIS, automatic REI remains active. During receiver OOF condition, REI is
transmitted as 0 in this mode.
AIS
The ability to transmit an all-1s AIS code is also supplied for the E3-G.832 mode
(similar to the E3-G.751 mode).
In E3-G.832 mode, transmission of AIS (unframed all 1) is enabled by setting
TxAlm0 high. When AIS is enabled, the framer ignores the inserted data and
Overhead bit settings and transmit an all-1s code, as long as TxAlm0 bit is set to 1.
Start of AIS transmission and termination in E3-G.832 is immediate with the setting
of TxAlm0.
NOTE:
With payload (when the method of overhead insertion is all with data)
From TEXT pin
Automatically generate it
Force RDI alarm sending by a control register
Mindspeed Technologies™
Automatic RDI transmission does not react to TR mismatch because the framer does
not check TR mismatches. When the method of overhead insertion is all with data,
setting AutoRAI or ExtRAI has no influence on the transmitted RDI-bit.
CX28342/3/4/6/8 Data Sheet
28348-DSH-001-B