XRT83VSH28ES Exar, XRT83VSH28ES Datasheet - Page 35

• Manufacturer Part Number: XRT83VSH28ES
• Description: Peripheral Drivers & Components - PCIs 8 CH E1 LIU SH (low cost version)
• Manufacturer: Exar

Specifications of XRT83VSH28ES

• Product Category: Peripheral Drivers & Components - PCIs
• Rohs: yes

REV. 2.0.0
This applications section describes common E1 system considerations along with references to application
notes available for reference where applicable.
The XRT83VSH28 supports several loopback modes for diagnostic testing. The following section describes
the local analog loopback, remote loopback, digital loopback, and dual loopback modes.
With local analog loopback activated, the transmit output data at TTIP/TRING is internally looped back to the
analog inputs at RTIP/RRING. External inputs at RTIP/RRING are ignored while valid transmit output data
continues to be sent to the line. A simplified block diagram of local analog loopback is shown in
F
N
With remote loopback activated, the receive input data at RTIP/RRING is internally looped back to the transmit
output data at TTIP/TRING. The remote loopback includes the Receive JA (if enabled). The transmit input
data at TCLK/TPOS/TNEG are ignored while valid receive output data continues to be sent to the system. A
simplified block diagram of remote loopback is shown in
F
4.0 E1 APPLICATIONS
4.1
4.1.1
4.1.2
IGURE
OTE
IGURE
: The transmit diagnostic features such as TAOS and QRSS take priority over the transmit input data at TCLK/TPOS/
TNEG.
19. S
20. S
Loopback Diagnostics
Local Analog Loopback
Remote Loopback
IMPLIFIED
IMPLIFIED
TNEG
RPOS
RNEG
TCLK
TPOS
RCLK
B
B
LOCK
LOCK
TNEG
RPOS
RNEG
TCLK
TPOS
RCLK
D
D
IAGRAM OF
IAGRAM OF
Decoder
Encoder
QRSS
QRSS
Encoder
Decoder
L
R
OCAL
EMOTE
JA
JA
A
JA
JA
8-CHANNEL E1 SHORT-HAUL LINE INTERFACE UNIT
NALOG
L
OOPBACK
32
Recovery
Data and
Control
Timing
Clock
Figure
Recovery
Data and
L
Control
Timing
Clock
OOPBACK
TAOS
20.
TAOS
Tx
Rx
Tx
Rx
TRING
RRING
TTIP
RTIP
TRING
RRING
TTIP
RTIP
XRT83VSH28
Figure
19.