PRELIMINARY
PM4318 OCTLIU
DATASHEET
PMC- 2001578
ISSUE 3
OCTAL E1/T1/J1 LINE INTERFACE DEVICE
Register 054H, 0D4H, 154H, 1D4H, 254H, 2D4H, 354H, 3D4H: CDRC Configuration
Bit
Type
Function
Default
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
AMI
0
0
0
0
0
0
0
0
LOS[1]
LOS[0]
Reserved
Reserved
ALGSEL
O162
Reserved
Reserved:
These bits must be a logic 0 for correct operation.
O162:
If the AMI bit is logic 0 in E1 mode, the Recommendation O.162 compatibility select bit
(O162) allows selection between two line code violation definitions:
If O162 is a logic 0, a line code violation is indicated if the serial stream does not match the
verbatim HDB3 definition given in Recommendation G.703. A bipolar violation that is not part
of an HDB3 signature or a bipolar violation in an HDB3 signature that is the same polarity as
the last bipolar violation results in a line code violation indication.
If O162 is a logic 1, a line code violation is indicated if a bipolar violation is of the same
polarity as the last bipolar violation, as per Recommendation O.162.
The O162 bit has no effect in T1 mode.
ALGSEL:
The Algorithm Select (ALGSEL) bit specifies the algorithm used by the DPLL for clock and
data recovery. The choice of algorithm determines the high frequency input jitter tolerance of
the CDRC. When ALGSEL is set to logic 1, the CDRC jitter tolerance is increased to
approach 0.5 Uipp for jitter frequencies above 20 kHz. When ALGSEL is set to logic 0, the
jitter tolerance is increased for frequencies below 20 kHz (i.e. the tolerance is improved by
20% over that of ALGSEL=1 at these frequencies), but the tolerance approaches 0.4 Uipp at
the higher frequencies.
AMI:
The alternate mark inversion (AMI) bit specifies the line coding of the incoming signal. A
logic 1 selects AMI line coding by disabling HDB3 decoding in E1 mode and B8ZS in T1
mode. In E1 mode, a logic 0 selects HDB3 line decoding which entails substituting an HDB3
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE
130
PMC [ PMC-SIERRA, INC ]
