DS21348

Manufacturer Part NumberDS21348
Description3.3V E1/T1/J1 Line Interface
ManufacturerDallas Semiconducotr
DS21348 datasheet
 


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RDNCD2 (10H): RECEIVE DOWN CODE DEFINITION REGISTER 2
(MSB)
C15
C14
SYMBOL
POSITION
C15
RDNCD2.7
C14
RDNCD2.6
C13
RDNCD2.5
C12
RDNCD2.4
C11
RDNCD2.3
C10
RDNCD2.2
C9
RDNCD2.1
C8
RDNCD2.0
8.2
Loopbacks
8.2.1 Remote Loopback (RLB)
When RLB (CCR6.6) is enabled, the DS21348 is placed into remote loopback. In this loopback, data
from the clock/data recovery state machine will be looped back to the transmit path passing through the
jitter attenuator if it is enabled. The data at the RPOS and RNEG pins will be valid while data presented
at TPOS and TNEG will be ignored. See for details.
If the Automatic Remote Loop Back Enable (CCR6.5) is set to a one, the DS21348 will automatically go
into remote loop back when it detects the loop up code programmed in the Receive Up Code Definition
Registers (RUPCD1 and RUPCD2) for a minimum of 5 seconds. When the DS21348 detects the loop
down code programmed in the Receive Loop Down Code Definition registers (RDNCD1 and RDNCD2)
for a minimum of 5 seconds, the DS21348 will come out of remote loop back. The ARLB can also be
disabled by setting ARLBE to a zero.
8.2.2 Local Loopback (LLB)
When LLB (CCR6.7) is set to a one, the DS21348 is placed into Local Loopback. In this loopback, data
on the transmit-side will continue to be transmitted as normal. TCLK and TPOS/TNEG will pass through
the jitter attenuator (if enabled) and be output at RCLK and RPOS/RNEG. Incoming data from the line at
RTIP and RRING will be ignored. If Transmit Unframed All Ones (CCR3.7) is set to a one while in LLB,
TTIP and TRING will transmit all ones while TCLK and TPOS/TNEG will be looped back to RCLK and
RPOS/RNEG. See for more details.
C13
C12
C11
DESCRIPTION
Receive Down Code Definition Bit 15
Receive Down Code Definition Bit 14
Receive Down Code Definition Bit 13
Receive Down Code Definition Bit 12
Receive Down Code Definition Bit 11
Receive Down Code Definition Bit 10
Receive Down Code Definition Bit 9
Receive Down Code Definition Bit 8
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(LSB)
C10
C9
C8