PRELIMINARY
PM4318 OCTLIU
DATASHEET
PMC- 2001578
ISSUE 3
OCTAL E1/T1/J1 LINE INTERFACE DEVICE
Register 009H, 089H, 109H, 189H, 209H, 289H, 309H, 389H:
Receive Line Interface Configuration #2
Bit
Type
Function
Default
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
R/W
RJATBYP
Unused
1
X
X
X
X
0
Unused
Unused
Unused
R/W
R/W
R/W
RSYNC_ALOSB
RSYNC_MEM
RSYNCSEL
0
0
RJATBYP:
The RJATBYP bit disables jitter attenuation in the receive direction. When receive jitter
attenuation is not being used, setting RJATBYP to logic 1 will reduce the latency through the
receiver section by typically 40 bits. When RJATBYP is set to logic 0, the LIU’s RSYNC
output is jitter attenuated. When the RJAT is bypassed, the octant’s RSYNC is not jitter
attenuated.
RSYNC_ALOSB:
The RSYNC_ALOSB bit controls the source of the loss of signal condition used to control the
behaviour of the receive reference presented on the RSYNC output. If RSYNC_ALOSB is a
logic 0, analogue loss of signal is used. If RSYNC_ALOSB is a logic 1, digital loss of signal is
used. When the LIU is in a loss of signal state, the RSYNC output is derived from XCLK or
held high, as determined by the RSYNC_MEM bit. When the LIU is not in a loss of signal
state, the RSYNC output is derived from the receive recovered clock of the selected octant.
The octant to be used as the source of RSYNC is determined by the RSYNC_SEL[2:0] bits.
RSYNC_MEM:
The RSYNC_MEM bit controls the octant’s RSYNC output under a loss of signal condition (as
determined by the RSYNC_ALOSB register bit). When RSYNC_MEM is a logic 1, the
octant’s RSYNC output is held high during a loss of signal condition. When RSYNC_MEM is
a logic 0, the octant’s RSYNC output is derived from the CSU 1x line rate clock during a loss
of signal condition.
RSYNCSEL:
The RSYNCSEL bit selects the frequency of the receive reference presented on the octant’s
RSYNC output. If RSYNCSEL is a logic 1, the octant’s RSYNC will be an 8 kHz clock. If
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
69
PMC [ PMC-SIERRA, INC ]
