
XRT86SH328
PRELIMINARY
268
28-CHANNEL DS1/E1 FRAMER/LIU WITH DS3 MUX & VT-MAPPER - SONET APPLICATIONS
REV. P1.0.6
BIT [7:2] - Reserved
BIT 1 - CRC-6 Source Select:
This READ/WRITE bit-field is used to specify the source of the CRC-6 bits, within the outbound DS1 data-stream.
`
0 = Configures the Transmit DS1 Framer block to internally compute and insert the CRC-6 bits within the outbound
DS1 data-stream.
`
1 = Configures the Transmit DS1 Framer block to externally accept data from the TxDS1DATA_n input pin (or from
upstream circuitry) and to insert this data into the CRC-6 bit-fields within the outbound DS1 data-stream.
BIT 0 - Framing Bits Source Select:
This READ/WRITE bit-field is used to specify the source of the Framing bits, within the outbound DS1 data-stream.
`
0 = Configures the Transmit DS1 Framer block to internally generate and insert the Framing bits within the outbound
DS1 data-stream
`
1 = Configures the Transmit DS1 Framer block to externally accept data from the TxDS1DATA_n input pin (or from
upstream circuitry) and to insert this data into the Framing bit-fields within the outbound DS1 data-stream.
BIT [7:6] - Reserved:
BIT [5:4] - Transmit Data Link Bandwidth[1:0]:
These two READ/WRITE bit-fields are used to select the Data Link Bandwidth (for the transmission of Data Link
Messages) within the outbound DS1 data-stream. Data Link Messages can be transmitted at a rate of either 4kHz or
2kHz.
T
ABLE
399: T1 F
RAMER
B
LOCK
- S
YNCHRONIZATION
MUX R
EGISTER
(A
DDRESS
= 0
X
N109,
WHERE
N
RANGES
IN
VALUE
FROM
0
X
01
TO
0
X
38)
BIT7
BIT6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Reserved
CRC-6
Source
Select
Framing Bits
Source
Select
R/O
R/W
R/W
R/W
R/O
R/O
R/W
R/W
0
0
0
0
0
0
0
0
T
ABLE
400: T1 F
RAMER
B
LOCK
- T
RANSMIT
D
ATA
L
INK
S
ELECT
R
EGISTER
(A
DDRESS
= 0
X
N10A,
WHERE
N
RANGES
IN
VALUE
FROM
0
X
01
TO
0
X
38)
BIT7
BIT6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Reserved
Transmit Data Link Band-
width[1:0]
Transmit D/E Time Source
Select[1:0]
Transmit Data Link Source
Select[1:0]
R/O
R/O
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
The Relationship between Transmit Data Link Bandwidth[1:0] and the resulting Bits/Bandwidth
available for the transport of Data Link Messages within the outbound DS1 data-stream
T
RANSMIT
D
ATA
L
INK
B
ANDWIDTH
[1:0]
R
ESULTING
B
ANDWIDTH
AVAILABLE
TO
TRANSPORT
D
ATA
L
INK
M
ESSAGES
WITHIN
OUTBOUND
DS1
DATA
-
STREAM
00
Data Link Bandwidth = 4kHzData Link Messages are being transported via every single
DL bit-field within the outbound DS1 data-stream
01
Data Link Bandwidth = 2kHz (Frames 1, 5, 9, ….)Data Link Messages are being trans-
ported via every other DL bit-field within the outbound DS1 data-stream.