DS21Q55 Maxim Integrated Products, DS21Q55 Datasheet - Page 80

• Manufacturer Part Number: DS21Q55
• Description: IC TXRX QUAD T1/E1/J1 SCT 256BGA
• Manufacturer: Maxim Integrated Products

Specifications of DS21Q55

• Function: Transceiver
• Interface: E1, J1, T1
• Number Of Circuits: 4
• Voltage - Supply: 3.14 V ~ 3.47 V
• Current - Supply: 75mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 256-BGA
• Includes: BERT Generator and Detector, Dual HDLC Controllers
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Power (watts): -

12.1 Line-Code Violation Count Register (LCVCR)
12.1.1 T1 Operation
T1 code violations are defined as bipolar violations (BPVs) or excessive 0s. If the B8ZS mode is set for
the receive side, then B8ZS codewords are not counted. This counter is always enabled; it is not disabled
during receive loss-of-synchronization (RLOS = 1) conditions.
count.
Table 12-A. T1 Line Code Violation Counting Options
12.1.2 E1 Operation
Either bipolar violations or code violations can be counted. Bipolar violations are defined as consecutive
marks of the same polarity. In this mode, if the HDB3 mode is set for the receive side, then HDB3
codewords are not counted as BPVs. If ERCNT.3 is set, then the LVC counts code violations as defined
in ITU O.161. Code violations are defined as consecutive bipolar violations of the same polarity. In most
applications, the framer should be programmed to count BPVs when receiving AMI code and to count
CVs when receiving HDB3 code. This counter increments at all times and is not disabled by loss-of-sync
conditions. The counter saturates at 65,535 and does not roll over. The bit-error rate on an E1 line would
have to be greater than 10
Table 12-B. E1 Line-Code Violation Counting Options
COUNT EXCESSIVE
E1 CODE VIOLATION SELECT
(ERCNT.0)
ZEROS?
Yes
Yes
No
No
(ERCNT.3)
0
1
-2
before the VCR would saturate
B8ZS ENABLED?
(T1RCR2.5)
Yes
Yes
No
No
COUNTED IN THE LCVCRs
80 of 237
BPVs
BPVs + 16 consecutive 0s
BPVs (B8ZS codewords not counted)
BPVs + 8 consecutive 0s
COUNTED IN THE LCVCRs
BPVs
CVs
(Table
Table 12-A
12-B).
shows what the LCVCRs