PM5381-BI PMC-Sierra, Inc., PM5381-BI Datasheet - Page 516

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

13.2
Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use
Document ID: PMC-2000489, Issue 4
HPT mode is used for systems which have devices that do not have J1 pointer interpretors so J1
indications are required on the TelecomBus interfaces. The S/UNI-2488 MUST be configured
for HPT mode when the S/UNI-2488 is being used as the APS protect device in an APS
application (see Figure 7).
The serial TelecomBus needs to be configured for MST or HPT modes. In MST mode, the J1
character is not overwritten by special 8B/10B characters. In HPT mode, it is specially marked to
indicate the J1 location.
On the S/UNI-2488 APSO interface, MST mode is activated for timeslot x by setting the
TMODEx[1:0] bits to logic ‘b00 in the T8TE TelecomBus Mode #1 and T8TE TelecomBus Mode
#2 registers. HPT mode is activated by setting TMODEx[1:0] to logic ‘b01. Note that regardless
of the MST/HPT setting in the transmit direction, valid H1/H2 bytes (J1 Pointer) are always
output on the TelecomBus, so a downstream device may operate in MST mode.
Cross Connect Mode of Operation
The processing of an STS-48c frame is the normal mode of operation of the S/UNI-2488,
however, the device can also be configured to process any mixture of STS-12c, STS-3c or STS-1
payloads within an STS-48 frame. This mode of operation is supported to allow for use in cross
connect applications where multiple S/UNI-2488s are connected to a cross connect fabric (such
as the PM5372 TSE) through the S/UNI-2488’s APS ports.
The XCONNECTMODE register bit of register 0001H (S/UNI Master Reset, Configuration and
Loopback register) controls the cross connect mode of operation. When this bit is set to logic 1,
the four RHPP and SVCA blocks of the S/UNI-2488 operate as independent STS-12 masters
(normally, these blocks are configured as one master and three slaves in order to process an STS-
48c payload). The RHPP and SVCA registers must then be programmed for their payload types.
Each RHPP processes the path overhead of any legal mix of STS-1/3c/12c (VC-3/4/4-4c)
payloads. The STS (VC) payloads are independently floating inside the transport frame and the
RHPP interprets each of the STS-1/3c/12c (AU3/4/4-4c) pointers in order to locate the boundaries
of the payloads i.e. the path trace bytes (J1). Once the STS (VC) payloads are located, the RHPP
extracts the path overhead bytes, the fixed stuff bytes and the entire synchronous payload
envelope (SPE) bytes.
The pointer interpreter state machines detect path loss of pointer (LOP-P) and path alarm
indication signal (AIS-P) defects on the STS (AU) pointers and report the status on two separate
ports PLOP and PAIS. The concatenation pointer interpreter state machines detect path loss of
pointer concatenation (LOPC-P) and path concatenation alarm indication signal (AISC-L)
defects on the STS (AU) concatenated pointers and report the status on two separate ports LOPC
and PAISC.
S/UNI-2488 Telecom Standard Product Datasheet
Released
516