XRT83SL28ES Exar, XRT83SL28ES Datasheet - Page 26

• Manufacturer Part Number: XRT83SL28ES
• Description: Peripheral Drivers & Components - PCIs 8 CH E1 LIU SH
• Manufacturer: Exar

Specifications of XRT83SL28ES

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

XRT83SL28
8-CHANNEL E1 SHORT-HAUL LINE INTERFACE UNIT
This applications section describes common E1 system considerations along with references to application
notes available for reference where applicable.
The XRT83SL28 supports several loopback modes for diagnostic testing. The following section describes the
local analog loopback, remote loopback, and digital loopback.
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 Figure 18.
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 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
Figure 19.
F
N
3.0 E1 APPLICATIONS
3.1
3.1.1
3.1.2
IGURE
OTE
IGURE
OTE
: TAOS takes priority over the transmit input data at TPOS/TNEG.
: Remote Loop Back takes priority over TAOS.
18. S
19. 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
Encoder
Decoder
L
R
OCAL
EMOTE
JA
JA
A
L
JA
JA
NALOG
OOPBACK
24
Data and
Recovery
Control
Timing
Clock
Recovery
Data and
L
Control
Timing
Clock
OOPBACK
TAOS
TAOS
Tx
Rx
Tx
Rx
TRING
TTIP
RRING
RTIP
TRING
RRING
TTIP
RTIP
xr
REV. 1.0.0