XRT84L38 View Datasheet(PDF) - Exar Corporation
Part Name
Description
MFG CO.
'XRT84L38' PDF : 453 Pages View PDF
REV. 1.0.1
1.6 Description of the Control Registers
XRT84L38
OCTAL T1/E1/J1 FRAMER
Clock Select Register (CSR) - T1 Mode(Indirect Address = 0xn0H, 0x00H)
BIT 7
BIT 6
BIT 5
BIT 4
BIT3
BIT 2
Bipolar
Violation
Insertion
T1, E1
Select
8KHz
Synchroniza-
tion
Enable
Clock Loss
Detection
Enable
OSCCLK
Frequency
Select Bit 1
OSCCLK
Frequency
Select Bit 0
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
1
0
0
BIT 1
Transmit
Timing
Source
Select Bit 1
R/W
0
BIT 0
Transmit
Timing
Source
Select Bit 0
R/W
1
BIT NUMBER
BIT NAME
BIT TYPE
BIT DESCRIPTION
7
Bipolar Violation Insertion R/W Bipolar Violation Insertion:
This READ/WRITE bit-field permits the user to insert Bipolar Vio-
lation to the transmit encoder.
The line coding for the DS1 signal should be bipolar. This signal-
ing technique consists of transmitting a binary "0" as zero volts,
while a binary "1" is transmitted as either a positive or negative
pulse, opposite in polarity to the previous pulse. A Bipolar Viola-
tion occurs when the alternate polarity rule is violated.
A zero-to-one transition of the bit will cause one Bipolar Violation
to be inserted into the outgoing data stream.
6
T1/E1 Select
R/W T1/E1 Select:
This READ/WRITE bit-field permits the user to select which
mode the framer will be operating.
When this bit is set to one:
The framer is in T1 mode.
When this bit is set to zero:
The framer is in E1 mode.
5
8KHz Synchronization
R/W 8KHz Synchronization Enable:
Enable
This READ/WRITE bit-field permits the user to activate and de-
activate the 8KHz synchronization of the framer.
An 8KHz external reference clock can be provided to the framer.
When this bit is set to one:
If the Transmit Clock Source Select bits are set to two, the trans-
mit clocks of all eight channels will be synchronized to the exter-
nal applied 8KHz reference clock and thus have the same
frequency and the same phase.
55
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