
á
PRELIMINARY
DS3 UNI FOR ATM
XRT7245
REV. 1.03
135
registers 1 through 4 (Address = 08h through 0Bh); as
depicted below.
Writing the Test Cell Header bytes into these registers
accomplishes two things:
It configures the Test Cell Generator to
produce Test Cells with these header byte
patterns; and
It informs the Test Cell Receiver of the
“header bytes” patterns of these Test Cells,
in order to help it to identify and collect these
cells for error-checking purposes.
a.
b.
4.3.1.2
The Test Cell Generator will automatically fill the
payload portion of these Test Cells with bytes that
are generated by an internal Pseudo-Random Byte
The Payload Bytes of the Test Cells
Sequence (PRBS) generator. These PRBS generated
bytes will ultimately be used by the Test Cell Receiver
in order to perform error-checking of the “post-routed”
Test Cells.
4.3.1.3
Test Cell Generator—Test Cell Traffic
Options
The user can configure the Test Cell Generator to
generate “Test Cells” based upon one of two traffic
options: The “One Shot” Mode, or the “Continuous”
Mode. The user can make this selection by writing
the appropriate value to Bit 2 of the Test Cell Control
and Status Register (Address = 06h); as depicted
below.
Test Cell Header Byte-1 Register (Address = 08h)
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Test Cell Header Byte 1
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
Test Cell Header Byte-2 Register (Address = 09h)
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Test Cell Header Byte 2
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
Test Cell Header Byte-3 Register (Address = 0Ah)
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Test Cell Header Byte 3
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0
Test Cell Header Byte-4 Register (Address = 0Bh)
B
IT
7
B
IT
6
B
IT
5
B
IT
4
B
IT
3
B
IT
2
B
IT
1
B
IT
0
Test Cell Header Byte 4
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
0
0
0
0
0
0
0
0