
XRT86SH328
PRELIMINARY
172
28-CHANNEL DS1/E1 FRAMER/LIU WITH DS3 MUX & VT-MAPPER - SONET APPLICATIONS
REV. P1.0.6
BIT[1:0] - Receive Tributary Size Select for VT# 0[1:0]:
These two READ/WRITE bit-fields are used to specify the VT-size (or the bit-rate to be supported by) that the Receive
VT-Mapper block (associated with Virtual Tributary Group # 0) will support.
2.10
DS3 MAPPER CONTROL REGISTERS
BIT[7:0] - Reserved
BIT 1 - Default_R Value:
When a DS3 signal is mapped into an STS-1/STS-3 SPE or a VC-3, there are numerous bits that are also stuffed into
the STS-1/STS-3 SPE or the VC-3 in order to accommodate the frequency differences between DS3 and an STS-
1/STS-3 SPE or an SDH VC-3.
One such bit is referred to as an R bit. Currently, the standards do not define a use for these bits. Hence, this bit can
be used as a proprietary communication link between two pieces of equipment.
This READ/WRITE bit-field is used to set the value for the R bits in the outbound STS-1/STS-3 SPE or SDH VC-3.
N
OTES
:
1.
The XRT86SH328 includes a corresponding READ-ONLY register bit, in which one can obtain the value
for the R bits in the incoming STS-1/STS-3 SPE or SDH VC-3. This register bit is located in BIT 1 (Received
R) within the DS3 Mapper Block - Receive Status Register - Byte 1 (Address = 0x0D06).
2.
This register bit is only active if the XRT86SH328 has been configured to operate in the M13 MUX which
is Asynchronously mapped into STS-1/STS-3 Mode.
BIT 0 - Default_O Value:
When a DS3 signal is mapped into a STS-1/STS-3 SPE (in SONET) or a VC-3 (in SDH), there are numerous bits that
are also stuffed into the STS-1/STS-3 SPE or the VC-3 in order to accommodate the frequency differences between
DS3 and an STS-1/STS-3 SPE or an SDH VC-3.
One such bit is referred to as an 0 bit. Currently, the standards do not define a use for these bits. Hence, this bit can
be used as a proprietary communication link between two pieces of equipment.
This READ/WRITE bit-field is used to set the value for the O bits in the outbound STS-1/STS-3 SPE or SDH VC-3.
N
OTES
:
1.
for the O bits in the incoming STS-1/STS-3 SPE or SDH VC-3. This register bit is located in BIT 0 (Received
O) within the DS3 Mapper Block - Receive Status Register - Byte 1 (Address = 0x0D06).
2.
This register bit is only active if the XRT86SH328 has been configured to operate in the M13 MUX
Asynchronously Mapped into STS-1/STS-3 Mode.
The XRT86SH328 includes a corresponding READ-ONLY register bit in which one can obtain the value
Resulting Size of VT#0
R
X
T
RIBUTARY
S
IZE
S
ELECT
- VT#0[1:0]
R
ESULTING
S
IZE
OF
VT # 0
00
VT-6
01
VT-3
10
VT-2/TU-12
11
VT-1.5/TU-11
T
ABLE
227: DS3 M
APPER
B
LOCK
- C
ONTROL
R
EGISTER
- B
YTE
1 (A
DDRESS
L
OCATION
= 0
X
0D02)
BIT7
BIT6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Reserved
Default_R
Default_O
R/O
R/O
R/O
R/O
R/O
R/O
R/W
R/W
0
0
0
0
0
0
1
1