S/UNI®-8x155 ASSP Telecom Standard Product Data Sheet
Released
DPLE:
The Diagnostic Path Loopback, DPLE bit enables the channel’s diagnostic loopback where
channel’s Transmit Path Overhead Processor (TPOP) is directly connected to its Receive
Path Overhead Processor (RPOP). When DPLE is logic one, loopback is enabled. Under
this operating condition, the channel continues to operates normally in the transmit
direction. When DPLE is logic zero, the channel operates normally.
LOOPT:
The LOOPT bit selects the source of timing for the transmit section of the channel. When
LOOPT is a logic zero, the transmitter timing is derived from input REFCLK (CSU). When
LOOPT is a logic one, the transmitter timing is derived from the recovered clock (Clock
Recovery Unit). LOOPT should not be set if the WANS is being used. The SDLEand
LOOPT bits should not be set high simultaneously. With internal cross bar enabled (external
or internal APS Mode) and LOOPT set, the transmit path will cause upstream device to
report frame errors.
SDLE:
The SDLE bit enables the serial diagnostic loopback. When SDLE is a logic one, the
channel’s transmit serial stream on the TXD+/- differential outputs is internally connected
to the received serial RXD+/- differential inputs. Under this operating condition, the
channel continues to operates normally in the transmit direction. The SDLEand LOOPT
bits should not be set high simultaneously.
SLLE:
The SLLE bit enables the channel’s line loopback mode. When SLLE is a logic one, the
channel’s recovered data from the receive serial RXD+/- differential inputs is mapped to the
TXD+/- differential outputs. Under this operating condition, the channel continues to
operates normally in the receive direction. LOOPT must be set high when SLLE is high for
proper operation.
Proprietary and Confidential to PMC-Sierra, Inc., and for its customers’ internal use.
Document No.: PMC- 2010299, Issue 2
121
PMC [ PMC-SIERRA, INC ]
