STANDARD PRODUCT
PM4351 COMET
DATA SHEET
PMC-1970624
ISSUE 10
COMBINED E1/T1 TRANSCEIVER
If RXELSTBYP is logic 1, the CMODE bit of the Receive Backplane
Configuration register must be logic 0 and the FPMODE bit of the Receive
Backplane Frame Pulse Configuration register must be logic 0.
RSYNC_MEM:
The RSYNC_MEM bit controls the RSYNC output under a loss of signal
condition (as determined by the RSYNC_ALOSB register bit). When
RSYNC_MEM is a logic 1, the RSYNC output is held high during a loss of
signal condition. When RSYNC_MEM is a logic 0, the RSYNC output is
derived from XCLK during a loss of signal condition.
RSYNCSEL:
The RSYNCSEL bit selects the frequency of the receive reference presented
on the RSYNC output. If RSYNCSEL is a logic 1, RSYNC will be an 8 kHz
clock. If RSYNCSEL is a logic 0, RSYNC will be an 1.544 MHz (T1) or
2.048 MHz (E1) clock.
WORDERR:
In E1 mode, the WORDERR bit determines how frame alignment signal
(FAS) errors are reported. When WORDERR is logic 1, one or more errors in
the seven bit FAS word results in a single framing error count. When
WORDERR is logic 0, each error in a FAS word results in a single framing
error count.
CNTNFAS:
In E1 mode, when the CNTNFAS bit is a logic 1, a zero in bit 2 of time slot 0
of non-frame alignment signal (NFAS) frames results in an increment of the
framing error count. If WORDERR is also a logic 1, the word is defined as
the eight bits consisting of the seven-bit FAS pattern and bit 2 of time slot 0 of
the next NFAS frame. When the CNTNFAS bit is a logic 0, only errors in the
FAS affect the framing error count.
CCOFA
The CCOFA bit determines whether the PMON counts Change-Of-Frame
Alignment (COFA) events or out-of-frame (OOF ) events. When CCOFA is
set to logic 1, COFA events are counted by PMON. When CCOFA is set to
logic 0, OOF events are counted by PMON. The CCOFA bit is only valid in
T1 mode.
PROPRIETARY AND CONFIDENTIAL
81
PMC [ PMC-SIERRA, INC ]
