
PRELIMINARY
XRT86SH328
183
REV. P1.0.6
28-CHANNEL DS1/E1 FRAMER/LIU WITH DS3 MUX & VT-MAPPER - SONET APPLICATIONS
BIT 2 - Reserved
BIT[1:0] - M23 Loop-back Codes[1:0]
These READ/WRITE bit-fields are used to specify the coding (or the values that the Transmit DS3 Framer block will set
the C-bits to) in order to request the remote terminal equipment to operate in the remote DS3 Loop-back Mode.
N
OTE
:
Anytime the Transmit DS3 Framer block has been configured to transmit a DS2 Loop-back request code to the
remote terminal equipment, then it will set the C-bits to the appropriate value (based upon the user-selection)
as specified in the above table. Further, the Transmit DS3 Framer block will transmit these DS2 Loop-back
request codes (to the remote terminal equipment) for the appropriate DS2 channel, whenever the user
F
IGURE
11. A
N
I
LLUSTRATION
OF
THE
F
UNCTIONAL
B
LOCK
D
IAGRAM
OF
THE
XRT86SH328,
WHENEVER
IT
HAS
BEEN
CONFIGURED
TO
OPERATE
IN
THE
M13 L
OCAL
L
OOP
-
BACK
M
ODE
Codes to Request Remote DS3 Loop-Back Mode
M23 L
OOP
-B
ACK
C
ODES
[1:0]
C-B
IT
S
ETTINGS
TO
R
EQUEST
DS2 L
OOP
-
BACK
C
ODES
C
OMMENTS
00/11
Cj1 = Cj2 = Cj3*
The Transmit DS3 Framer block will invert the state of
the Cj3 bit (from that of the corresponding Cj1 and Cj2
bits) in order to request that the remote terminal execute
a DS2 remote Loop-back within the jth DS2 Channel.
01
Cj1 = Cj2* = Cj3
The Transmit DS3 Framer block will insert the state of
the of the Cj2 bit (from that of the corresponding Cj1 and
Cj3 bits) in order to request that the remote terminal exe-
cute a remote Loop-back within the jth DS2 Channel.
10
Cj1* = Cj2 = Cj3
The Transmit DS3 Framer block will invert the state of
the Cj1 bit (from that of the corresponding Cj2 and Cj3
bits) in order to request that the remote terminal execute
a remote Loop-back within the jth DS2 Channel.
STS-1/
STS-3
Telecom
Bus
Interface
Transmit
STS-1/3
TOH
Processor
Block
Receive
STS-1/3
TOH
Processor
Block
Transmit
STS-1 POH
Processor
Block
Receive
STS-1 POH
Processor
Block
VT/TU
De-Mapper
Block
Receive
DS3
Framer
Block
Transmit
DS3
Framer
Block
M23
MUX
Block
M23
De-MUX
Block
Ingress
Direction
Receive
DS1/E1
Framer
Block
Egress
Direction
Receive
DS1/E1
Framer
Block
Ingress
Direction
Transmit
DS1/E1
Framer
Block
Egress
Transmit
DS1/E1
Framer
Block
Receive
DS1/E1
LIU
Block
Transmit
DS1/E1
LIU
Block
DS3/
STS-1
LIU
Interface
M12
MUX
Block
M12
De-MUX
Block
DS1/E1
Jitter
Atten
Block
DS1/E1 Channel 0
DS1/E1 Channel 0
DS2 Channel 0
From DS1/E1 Channels 1 - 27
From DS2 Channels 1 - 6
To DS2 Channels 1 - 6
From DS1/E1 Channels 1 - 3
To DS1/E1 Channels 1 - 3
To DS1/E1
Channels 1 - 27
VT/TU
Mapper
Block
DS2 Channel 0