XRT83L38 Datasheet, PDF (60/91 Pages) Exar Corporation – OCTAL T1/E1/J1 LH/SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR

XRT83L38
OCTAL T1/E1/J1 LH/SH TRANSCEIVER WITH CLOCK RECOVERY AND JITTER ATTENUATOR
REV. 1.0.0
TABLE 22: MICROPROCESSOR REGISTER #3, BIT DESCRIPTION
D5
CODES_n Encoding and Decoding Select:
R/W
0
Writing a “0” to this bits selects HDB3 or B8ZS encoding and
decoding for channel number n. Writing “1” selects an AMI
coding scheme. This bit is only active when single rail mode is
selected.
D4
RXRES1_n Receive External Resistor Control Pin 1: In Host mode, this bit R/W
0
along with the RXRES0_n bit selects the value of the external
Receive fixed resistor according to the following table;
RXRES1_n
0
0
RXRES0_n
0
1
Required Fixed External
RX Resistor
No external Fixed
R es is to r
240Ω
1
0
210Ω
1
1
150Ω
D3
RXRES0_n Receive External Resistor Control Pin 0: For function of this R/W
0
bit see description of D4 the RXRES1_n bit.
D2
INSBPV_n Insert Bipolar Violation: When this bit transitions from “0” to R/W
0
“1”, a bipolar violation is inserted in the transmitted data
stream of the selected channel number n. Bipolar violation can
be inserted either in the QRSS pattern, or input data when
operating in single-rail mode. The state of this bit is sampled
on the rising edge of the respective TCLK_n.
NOTE: To ensure the insertion of a bipolar violation, a “0”
should be written in this bit location before writing a
“1”.
D1
INSBER_n Insert Bit Error: With TDQRSS enabled, when this bit transi- R/W
0
tions from “0” to “1”, a bit error will be inserted in the transmit-
ted QRSS pattern of the selected channel number n. The state
of this bit is sampled on the rising edge of the respective
TCLK_n.
NOTE: To ensure the insertion of bit error, a “0” should be
written in this bit location before writing a “1”.
D0
TRATIO_n Transformer Ratio Select: In the external termination mode, R/W
0
writing a "1" to this bit selects a transformer ratio of 1:2 for the
transmitter. Writing a "0" sets the transmitter transformer ratio
to 1:2.45. In the internal termination mode the transmitter
transformer ratio is permanently set to 1:2 and the state of this
bit has no effect.
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