Bt8370/8375/8376
Fully Integrated T1/E1 Framer and Line Interface
BPV
3.7 Receive LIU Registers
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
0
1
1
1
1
T1/E1N
X
0
0
1
1
RZCS
X
0
1
0
1
No error
All BPVs, including HDB3 coded BPV
Code violation per ITU 0.162 (two consecutive BPVs of
same polarity)
All BPVs, including B8ZS coded BPV
Only BPVs that are not part of B8ZS
BPV Status
EYEOPEN
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]
PRE_EQ
022—Receive LIU Configuration (RLIU_CR)
7
FRZ_SHORT
6
HI_CSLICE
5
AGC[1]
4
AGC[0]
3
EQ_FRZ
2
OOR_BLOCK
1
RLB0
0
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
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
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
HI_CSLICE
AGC[1:0]
EQ_FRZ
N8370DSE
Conexant
3-41
CONEXANT [ CONEXANT SYSTEMS, INC ]
