
XRT86SH221
PRELIMINARY
149
SDH-TO-PDH FRAMER/MAPPER WITH INTEGRATED 21-CHANNEL E1 SH LIU
REV. P1.0.5
BIT [7:5] - Unused
BIT 4 - Receive Section Trace Message Buffer Read Selection
This READ/WRITE bit-field is used to specify which of the following Receive Section Trace Message buffer segments
to read.
The Actual Receive Section Trace Message Buffer which contains the contents of the most recently received
(and accepted) Section Trace Message via the incoming STM-0 data-stream.
The Expected Receive Section Trace Message Buffer which contains the contents of the Section Trace
Message that the user expects to receive. The contents of this particular buffer are usually specified by the
user.
0 - Executing a READ to the Receive Section Trace Message Buffer address space, will return contents within the
Actual Receive Section Trace Message buffer.
1 - Executing a READ to the Receive Section Trace Message Buffer address space will return contents within the
Expected Receive Section Trace Message Buffer.
N
OTE
:
In the case of the Receive STM-1 TOH Processor block, the Receive Section Trace Message Buffer is located
at Address Location 0x0400 through 0x043F.
BIT 3 - Receive Section Trace Message Accept Threshold
This READ/WRITE bit-field is used to select the number of consecutive times that the Receive STM-0 TOH Processor
block must receive a given Section Trace Message, before it is accepted, as described below. Once a given Section
Trace Message has been accepted then it can be read out of the Actual Receive Section Trace Message Buffer.
0 - The Receive STM-0 TOH Processor block accepts the Section Trace Message after it has received it the third time
in succession.
1 - The Receive STM-0 TOH Processor block accepts the Section Trace Message after it has received in the fifth time
in succession.
BIT 2 - Section Trace Message Alignment Type
This READ/WRITE bit-field is used to specify how the Receive STM-0 TOH Processor block will locate the boundary of
the Section Trace Message within the incoming STM-0 data-stream, as indicated below.
0 - Message boundary is indicated by Line Feed.
1 - Message boundary is indicated by the presence of a 1 in the MSB of the first byte (within the Section Trace
Message).
BIT [1:0] - Receive Section Trace Message Length[1:0]
These READ/WRITE bit-fields are used to specify the length of the Section Trace Message that the Receive STM-0
TOH Processor block will receive. The relationship between the content of these bit-fields and the corresponding
Receive Section Trace Message Length is presented below
T
ABLE
93: R
ECEIVE
STM-0 T
RANSPORT
- R
ECEIVE
S
ECTION
T
RACE
M
ESSAGE
B
UFFER
C
ONTROL
R
EGISTER
(RSTMBCR = 0
X
024F)
BIT 7
BIT 6
BIT 5
BIT 4
BIT 3
BIT 2
BIT 1
BIT 0
Unused
Receive Sec-
tion Trace
Message
Buffer Read
Select
Receive Sec-
tion Trace
Message
Accept
Threshold
Section Trace
Message
Alignment
Type
Receive Section Trace Mes-
sage Length[1:0]
R/O
R/O
R/O
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0