XRT7302IQ80 View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT7302IQ80' PDF : 77 Pages View PDF
XRT7302 2 CHANNEL E3/DS3/STS-1 LINE INTERFACE UNIT
REV. 1.1.0
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TABLE 2: SELECTING THE DATA RATE FOR CHANNEL 1, (WITHIN THE XRT7302 DEVICE), VIA THE "E3_CH1" AND
"STS-1/DS3_CH1" INPUT PINS (HARDWARE MODE)
DATA RATE
E3 (34.368 Mbps)
DS3 (44.736 Mbps)
STS-1 (51.84 Mbps)
STATE OF E3_CH1 PIN
(PIN 20)
1
0
0
STATE OF STS-1/(DS3_CH1)
PIN
(PIN 21)
X (Don't Care)
MODE OF B3ZS/HDB3 ENCODER/
DECODER BLOCKS
HDB3
0
B3ZS
1
B3ZS
b. When operating in the "Host" Mode.
In order to configure Channel 1 into the appropriate
mode, the user must write the appropriate values into
the "STS-1/DS3_Ch1" and "E3_Ch1" bit-fields, within
Command Register CR4, as illustrated below.
COMMAND REGISTER, CR4 (ADDRESS = 0X04)
D4
D3
D2
D1
D0
X STS-1/(DS3_Ch1) E3_Ch1 LLB1 RLB1
x
x
x
x
x
Table 3 relates the values of these two bit-fields to the
selected data rates.
TABLE 3: SELECTING THE DATA RATE FOR CHANNEL 1
(WITHIN THE XRT7302 DEVICE); VIA THE "STS-1/
DS3_CH1" AND THE "E3_CH1" BIT-FIELDS, WITHIN
COMMAND REGISTER CR4 (HOST MODE)
SELECTED STS-1/(DS3_CH1)
DATA RATE
(D3)
E3
X (Don't Care)
DS3
0
STS-1
1
"E3_CH1" (D2)
1
0
0
By making these selections, the user is doing the
following:
• Configuring the VCO Center Frequency of the
Clock Recovery Phase-Locked-Loop (within Chan-
nel 1) to match the selected data rate.
• Configuring the "B3ZS/(HDB3)" Encoder and
Decoder blocks to support B3ZS Encoding/Decod-
ing, if the DS3 or STS-1 data rates were selected;
or
• Configuring the "B3ZS/(HDB3)" Encoder and
Decoder blocks to support HDB3 Encoding/Decod-
ing, if the E3 data rate was selected.
• Configuring the on-chip "Pulse-Shaping" circuitry to
generate Transmit Output pulses, of the appropriate
shape and width to meet the applicable pulse tem-
plate requirement.
• Establishes the LOS Declaration/Clearance Criteria
(for Channel 1). (See section 3.6)
1.2 CONFIGURING CHANNEL 2
a. When operating in the "Hardware" Mode
In order to configure Channel 2 into the appropriate
mode, the user must set the “E3_Ch2” and the
“STS-1/(DS3_Ch2)” input pins to the appropriate
logic states as presented below in Table 4.
TABLE 4: SELECTING THE DATA RATE FOR CHANNEL 2 (WITHIN THE XRT7302 DEVICE) VIA THE "E3_CH2" AND
"STS-1/DS3_CH2" INPUT PINS (HARDWARE MODE)
DATA RATE
E3 (34.368 Mbps)
DS3 (44.736 Mbps)
STS-1 (51.84 Mbps)
STATE OF E3_CH2 PIN
(PIN 39)
1
0
0
STATE OF STS-1/
(DS3_CH2) PIN
(PIN 41
X (Don't Care)
0
1
MODE OF B3ZS/(HDB3) ENCODER/DECODER
BLOCKS
HDB3
B3ZS
B3ZS
b. When operating in the "Host" Mode.
In order to configure Channel 2 into the appropriate
mode, the user must write the appropriate values into
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