DS3170N+ Maxim Integrated Products, DS3170N+ Datasheet - Page 106

• Manufacturer Part Number: DS3170N+
• Description: IC TXRX DS3/E3 100-CSBGA
• Manufacturer: Maxim Integrated Products

Specifications of DS3170N+

• Function: Single-Chip Transceiver
• Interface: DS3, E3
• Number Of Circuits: 1
• Voltage - Supply: 3.135 V ~ 3.465 V
• Current - Supply: 120mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 100-LBGA
• Includes: DS3 Framers, E3 Framers, HDLC Controller, On-Chip BERTs
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power (watts): -

DS3170 DS3/E3 Single-Chip Transceiver
as the values for the first one. The third bipolar one is generated according to the normal AMI rules. When an EXZ
error is to be inserted, the Transmit Line Interface waits for the next occurrence of three (four) consecutive zeros on
the bipolar signal, and inhibits the insertion of a B3ZS (HDB3) signature. There must be at least one intervening
one between consecutive BPV or EXZ errors. A single BPV or EXZ error inserted must be detected as a single
BPV/EXZ error at the far-end, and not cause any other type of error to be detected. For example, if a BPV error is
inserted, the far-end should not also detect a data error. If a second error insertion request of a given type (BPV or
EXZ) is initiated before a previous request has been completed, the second request will be ignored.
The outgoing bipolar data stream consists of positive pulse data (TPOS) and negative pulse data (TNEG). TPOS
and TNEG are updated on the rising edge of TLCLK.
10.10.5 Receive Line Interface
The Receive Line Interface receives a bipolar signal. The incoming bipolar data line consists of positive pulse data
(RPOS), negative pulse data (RNEG), and clock (RLCLK) signals. RPOS and RNEG are sampled on the rising
edge of RLCLK. The incoming bipolar signal is checked for a Loss Of Signal (LOS) condition, and passed on to
B3ZS/HDB3 Decoder. An LOS condition is declared if both RPOS and RNEG do not have any transitions for 192
clock cycles. The LOS condition is terminated after 192 clock cycles without any EXZ errors. Note: When zero
suppression (B3ZS or HDB3) decoding is disabled, the LOS condition is cleared, and cannot be detected.
10.10.6 B3ZS/HDB3 Decoder
The B3ZS/HDB3 Decoder receives a bipolar signal from the LIU (or the RPOS/RNEG pins). The incoming bipolar
signal is checked for a Loss of Signal (LOS) condition. An LOS condition is declared if both the positive pulse data
and negative pulse data signals do not have any transitions for 192 clock cycles. The LOS condition is terminated
after 192 clock cycles without any EXZ errors.
B3ZS/HDB3 Decoder performs EXZ detection, zero suppression decoding, BPV detection, and bipolar to unipolar
conversion.
EXZ detection checks the bipolar data stream for excessive zeros (EXZ) errors. In B3ZS mode, an EXZ error is
declared whenever there is an occurrence of 3 or more zeros. In HDB3 mode, an EXZ error is declared whenever
there is an occurrence of 4 or more zeros. EXZ errors are accumulated in the EXZ counter (LINE.REXZCR
register).
Zero-suppression decoding converts B3ZS or HDB3 encoded bipolar data into an AMI bipolar signal. In B3ZS
mode, the encoded bipolar signal is checked for a B3ZS signature. If a B3ZS signature is found, it is replaced with
three zeros. In HDB3 mode, the encoded bipolar signal is checked for an HDB3 signature. If an HDB3 signature is
found, it is replaced with four zeros. The format of both an HDB3 signature and a B3ZS signature is programmable.
When LINE.RCR.RZSF = 0, the decoder will search for a zero followed by a BPV in B3ZS mode, and in HDB3
mode it will search for two zeros followed by a BPV. If LINE.RCR.RZSF = 1, the same criteria is applied with an
additional requirement that the BPV must be the opposite polarity of the previous BPV. Please refer to
Figure
10-25
and
Figure
10-26. Zero suppression decoding is also programmable (on or off). Note: Immediately after a
reset or a LOS condition, the first B3ZS/HDB3 signature to be detected will not depend upon the polarity of any
BPV contained within the signature.
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