29704-BRF-003-A Datasheet, PDF (1/2 Pages) M/A-COM Technology Solutions, Inc. – OptiPHY F155 Quad OC-3/STM-1 ATM/POS PHY

OptiPHY^™ F155 Quad OC-3/STM-1 ATM/POS PHY
CX29704/2/1
Four-Channel CX29704, two-channel
CX29702, one-channel CX29701 155Mbps
ATM/POS PHY with Clock and Data Recovery
The CX2970x is an integrated circuit that implements
four-channel ATM/Packet over SONET/SDH (POS)
processing functions at 155.52 Mbps. The device contains
both the PMD and TC sublayers and features a UTOPIA
Level 2 interface to the ATM layer or, optionally, a POS
PHY Level 2 interface to the link layer. This device also
includes dedicated serial ports for the insertion and
extraction of the DCC overhead bytes.
SONET/SDH Processing
In the transmit path, this device generates all section,
line and path overhead bytes, in addition to implementing
framing, scrambling and alarm indication functions. On the
receive path, all framing, descrambling, alarm detection and
pointer interpretations are performed. A serial interface
inserts and extracts the section or line DCC bytes.
ATM Cell Processing
For ATM cell processing, the CX2970x performs all cell
encapsulation, HEC calculation, cell delineation, payload
scrambling/descrambling and idle cell insertion/filtering.
Data is exchanged with a higher-layer device using a
UTOPIA Level 2 interface.
POS Processing
In POS mode, the CX2970x performs all HDLC framing,
scrambling/descrambling, interframe fills, FIFO management
> KEY FEATURES
> Integrated clock and data
recovery (CDR)
> Clock recovery conforms
to GR-253-CORE jitter
requirements
> Low-power, 3.3 V CMOS
technology
> Synthesizes a 155 MHz Tx
clock from a 19 MHz input
> UTOPIA Level 2 and POS
Level 2 system interfaces
and stuffing/destuffing operations. Data is exchanged
with higher-layer devices using a POS PHY Level 2 interface.
Line Interface
The CX2970x includes on-chip clock and data recovery
(CDR) for 155.52 Mbps line rates. This CDR block also
implements the serialize/deserialize functions. On
the receive path, after recovery of the data and its
associated clock, data is sent to the SONET/SDH
framer via a parallel bus.
Higher-Layer Interface
The CX2970x supports several interfaces to higher-
layer devices. The component supports a UTOPIA Level
2 interface for ATM cells and a POS PHY interface for
PPP packets in POS mode. Up to eight CX2970x devices
can be connected to a single higher-level device
(multiport ATM-layer or POS-layer device),
in various operation modes.
>