PM7346 datasheet(79/419 Pages) PMC

79 / 419 page

PM7346 S/UNI-QJET

DATASHEET

PMC-960835

ISSUE 6

SATURN QUAD USER NETWORK INTERFACE FOR J2, E3, T3

PMC-SIERRA, INC. PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA INC., AND ITS CUSTOMERS’ INTERNAL USE 58

When the C-bit parity application is enabled, both the far end alarm and control

(FEAC) channel and the path maintenance data link are extracted. Codes in the

FEAC channel are detected by the Bit Oriented Code Detector (RBOC). HDLC

messages in the Path Maintenance Data Link are received by the Data Link

Receiver (RDLC).

The T3-FRMR can be enabled to automatically assert the RAI indication in the

outgoing transmit stream upon detection of any combination of LOS, OOF or

RED, or AIS. The T3-FRMR can also be enabled to automatically insert C-bit

Parity FEBE upon detection of receive C-bit parity error.

The T3-FRMR extracts the entire DS3 overhead (56 bits per M-frame) using the

ROH output, along with the ROHCLK, and ROHFP outputs.

The T3-FRMR may be configured to generate interrupts on error events or status

changes. All sources of interrupts can be masked or acknowledged via internal

registers. Internal registers are also used to configure the T3-FRMR. Access to

these registers is via a generic microprocessor bus.

9.2

E3 Framer

The E3 Framer (E3-FRMR) Block integrates circuitry required for decoding an

HDB3-encoded signal and framing to the resulting E3 bit stream. The E3-FRMR

is directly compatible with the G.751 and G.832 E3 applications.

The E3-FRMR searches for frame alignment in the incoming serial stream based

on either the G.751 or G.832 formats. For the G.751 format, the E3-FRMR

expects to see the selected framing pattern error-free for three consecutive

frames before declaring INFRAME. For the G.832 format, the E3-FRMR expects

to see the selected framing pattern error-free for two consecutive frames before

declaring INFRAME. Once the frame alignment is established, the incoming

data is continuously monitored for framing bit errors and byte interleaved parity

errors (in G.832 format).

While in-frame, the E3-FRMR also extracts various overhead bytes and

processes them according to the framing format selected:

In G.832 E3 format, the E3-FRMR extracts:

• the Trail Trace bytes and outputs them as a serial stream for further

processing by the Trail Trace Buffer (TTB) block;

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