Bt8370/8375/8376
Fully Integrated T1/E1 Framer and Line Interface
3.7 Receive LIU Registers
BPV
Bipolar Violation—Reports one or more bipolar violations detected on RTIP/RRING data
inputs. Depending on RZCS [addr 040], the BPV may include bipolar violations received as
part of a B8ZS or HDB3 0 code substitution. Detection of BPV or LCV errors can be selected,
regardless of whether or not receive ZCS decoding is enabled [RAMI; addr 040]. BPV is
latched active high upon detection of the first error. The active high hold interval is defined by
LATCH_ERR [addr 046]. BPV errors are also accumulated in LCV count [addr 054, 055].
BPV
T1/E1N RZCS
BPV Status
0
1
1
X
0
X
0
No error
All BPVs, including HDB3 coded BPV
0
1
Code violation per ITU 0.162 (two consecutive BPVs of
same polarity)
1
1
1
1
0
1
All BPVs, including B8ZS coded BPV
Only BPVs that are not part of B8ZS
EYEOPEN
PRE_EQ
Equalization State—EYE OPEN indicates the real-time status of RLIU adaptive equalizer, and
is intended only for diagnostic testing. Remains active as long as a valid receive AMI signal is
present on RTIP/RRING. When SQUELCH [addr 020] is enabled and EYEOPEN status is 0,
RLIU data outputs are forced to 0.
0= Indicates the received signal is not valid.
1= Indicates the received signal is valid and the RPLL is locked.
Pre-Equalizer status. Indicates whether the pre-equalizer is enabled (on) or disabled (off).
0= PRE_EQ is off
1= PRE_EQ is on
See PRE_EQ register [addr 02A]
022—Receive LIU Configuration (RLIU_CR)
7
6
5
4
3
2
1
0
FRZ_SHORT
HI_CSLICE
AGC[1]
AGC[0]
EQ_FRZ
OOR_BLOCK
RLB0
LONG_EYE
FRZ_SHORT
Freeze equalizer for short lines—When set, the equalizer is not updated when the received
signal is approximately –15 dB or larger.
0 = equalizer updates for all lines
1 = enable equalizer freezing if short line
HI_CSLICE
AGC[1:0]
High Clock Slicer Threshold.
0 = normal operation
AGC Observation Window—Set to 0x11 for normal operation. Determines the period, in bit
times, for Automatic Gain Control updates.
00 = 32 bits
01 = 128 bits
10 = 512 bits
11 = 2048 bits
EQ_FRZ
Freeze EQ Coefficients.
0 = normal operation, equalizer always updates depending on
FRZ_SHORT setting
1 = freeze coefficients, equalizer does not update. Does not affect AGC
operation
N8370DSE
Conexant
3-41
CONEXANT [ CONEXANT SYSTEMS, INC ]
