PM5381-BI PMC-Sierra, Inc., PM5381-BI Datasheet - Page 108

• Manufacturer Part Number: PM5381-BI
• Description: ATM UNI, Single Channel ATM PHY Interface for 2488.32Mbps
• Manufacturer: PMC-Sierra, Inc.

10.21.1 Output APS Serial Data Interface (T8TE, APISO, TXLV)
10.21.2 Input APS Serial Data Interface (RXLV, DRU, R8TD)
10.21.3 LVDS Transmit Reference (TXREF)
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2000489, Issue 4
The Output APS Serial Data Interface uses the four sets of T8TE, APISO and TXLV blocks to
transmit a SONET (SDH) stream to a working or protect mate. The SONET (SDH) OC-48
stream is selected from either the THPP or SVCA block and serialized on a 777.76 Mbps serial
TelecomBus. When the S/UNI-2488 is configured as the working mate, the Output APS Serial
Data Interface selects the transmit path processed SONET (SDH) stream from the THPP block
and transmits it through the 4 differential LVDS pairs, APSO_P/ APSO_N[4:1] to the protect
mate where the stream is line and section processed. When the S/UNI-2488 is configured as the
protect mate, the Output APS Serial Data Interface selects receive path terminated SONET (SDH)
stream from the SVCA block and transmit it through the 4 differential LVDS pairs, APSO_P/
APSO_N[4:1] to the working mate. The working mate will then process the SONET (SDH)
payload (ATM or POS) and pass the results to the system via the UTOPIA Level 3 or POSPHY
Level 3 interface.
There are four sets of T8TE, APISO and TXLV blocks. Each set implements one of four serial
streams that make up the output serial TelecomBus. The T8TE block takes a SONET (SDH)
stream and 8B/10B encodes it. The APISO block performs a parallel to serial conversion. The
TXLV block is a differential LVDS transmitter.
The Input APS Serial Data Interface uses the four sets of RXLV, DRU and R8TD blocks to
receive a SONET (SDH) stream from a working or protect mate via a serial TelecomBus. The
received SONET (SDH) OC-48 stream is passed to either the RCFP or TRMP block for further
processing. When the S/UNI-2488 is configured as the working mate and when a failure
condition exists, a receive path processed SONET (SDH) stream is expected from the protect
mate on the 4 differential LVDS pairs, APSI_P/ APSI_N[4:1]. The S/UNI-2488 will pass this
received stream to the RCFP for ATM or POS payload processing. When the S/UNI-2488 is
configured as the protect mate and when a failure condition exists, a transmit path processed
SONET (SDH) stream is expected from the working mate on the 4 differential LVDS pairs,
APSI_P/ APSI_N[4:1]. The S/UNI-2488 will pass this received stream to the TRMP for SONET
line and section insertion before it is transmitted.
There are four sets of RXLV, DRU and R8TD blocks. Each set implements one of four serial
streams that make up the input serial TelecomBus. The RXLV block is a differential LVDS
receiver. The DRU recovers the 777.76 Mbps 8B/10B encoded serial stream and deserializes it
for the R8TD block. The R8TB block converts the deserialized 8B/10B stream into the a SONET
(SDH) stream.
The TXLVREF provides an on-chip bandgap voltage reference (1.20V ±5%) and a precision
current to the TXLVs. The reference voltage is used to control the common-mode level of the
TXLV output, while the reference current is used to control the output amplitude. The precision
currents are generated by forcing the reference voltage across an external, off-chip 3.16KW (±1%)
resistor. The resulting current is then mirrored through several individual reference current
outputs, so each TXLV receives its own reference current.
S/UNI-2488 Telecom Standard Product Datasheet
Released
108