LXT362 — Integrated T1 LH/SH Transceiver for DS1/DSX-1 or PRI Applications
Figure 6. Local Loopback
Local Loopback with JA in Receive Path
Timing &
TCLK
TTIP
Control
TPOS
TRING
TNEG
* If Enabled
RCLK
RPOS
RNEG
Timing
Recovery
RTIP
JA*
RRING
Local Loopback with JA in Transmit Path
Timing &
TTIP
TCLK
TPOS
TNEG
Control
JA*
TRING
* If Enabled
RCLK
RPOS
RNEG
RTIP
Timing
Recovery
RRING
2.7.1.2
Analog Loopback (ALOOP)
See Figure 7. Analog loopback (ALOOP) exercises the maximum number of functional blocks.
ALOOP operation disconnects the RTIP/RRING inputs from the line and routes the transmit
outputs back into the receive inputs. This tests the encoders/decoders, jitter attenuator, transmitter,
receiver and timing recovery sections.
In Hardware mode, ALOOP becomes active when the LLOOP pin is floating (i.e. Midrange). In
Host mode, setting bit CR2.EALOOP = 1 commands ALOOP. Note that ALOOP overrides all
other loopback modes.
Figure 7. Analog Loopback
Analog Loopback with JA in Receive Path
TCLK
TPOS
TNEG
TTIP
TRING
* If Enabled
RCLK
RPOS
RNEG
RTIP
Timing
JA*
Recovery
RRING
Analog Loopback with JA in Transmit Path
TCLK
TPOS
TNEG
TTIP
JA*
TRING
* If Enabled
RCLK
RPOS
RNEG
RTIP
Timing
Recovery
RRING
22
Datasheet
INTEL [ INTEL ]
