CD22103A Datasheet, PDF (4/7 Pages) Intersil Corporation – CMOS HDB3 High Density Bipolar 3 Transcoder for 2.048/8.448Mb/s Transmission Applications

CD22103A
The received 4 data bits previous to reception of the violation
pulse have not been the sequence BX00 (where X = don't
care). The error signal (ERR) remains low.
NOTES:
1. The data sequences B000V and BB00V are valid HDB3 codings
of the NRZ binary sequence 10000.
2. The error signal (ERR) count, is the accurate number of all single
bit errors.
• AMl Signals HDB3/AMl = Low
- A coding error (ERR) is signaled when a violation pulse
(+V) is received.
• In Either the HDB3 or AMI Mode
- When high levels appear simultaneously on both HDB3
inputs (+ HDB3 IN, -HDB3 IN) a logical one is assumed
in the HDB3/AMl input stream and the error signal
(ERR) goes high for the duration of the violation.
Alarm Inhibit Signal
- The alarm output (AIS) is set high if, in two successive
periods of the external Reset Alarm Signal (RAlS), less
than three zeros are received.
- The alarm output (AlS) is reset low when three or more
zeros are received during two Reset Alarm Signal periods.
Transcoder Operation
Transmitter Coder (See Figure 1)
The HDB3/AMI transmitter coder operates on 4-bit serial
strings of NRZ binary data and a synchronous transmitter
clock (CTX). NRZ binary data is serially clocked into the
transmitter on the negative transition of the (CTX) clock.
HDB3/AMI coding is performed on the 4-bit string, and
HDB3/AMI binary output data is clocked out to the (+HDB3
OUT, -HDB3 OUT) outputs on the positive transition of the
transmitter clock (CTX) 3 1/2 clock pulses after the data
appeared at the (NRZ-IN) input.
Receiver Decoder (See Figure 2)
The HDB3/AMI receiver decoder operates on 4-bit serial
strings of binary coded HDB3/AMI signals, and a synchro-
nous receiver clock (CRX), HDB3/AMI binary data is serially
clocked into the receiver on the positive transition of the
(CRX) clock. HDB3/AMI decoding is performed on the 4-bit
string, and NRZ binary output data is clocked out to the
(NRZ-OUT) output on the positive transition of the receiver
clock (CRX) 4 clock pulses after the data appeared at the
(+HDB3 IN, -HDB3 IN) inputs.
HANDLING DELAY
CTX
NRZ - IN
+HDB3 OUT
HDB3
CODED
-HDB3 OUT
EXTERNAL GENERATED
TERNERY HDB3
+HDB3 OUT
AMI
CODED
-HDB3 OUT
EXTERNAL GENERATED
AMI
FIGURE 1. TRANSMITTER CODER OPERATION TIMING WAVEFORMS - NRZ TO HDB3/AMI CODING
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