Agilent Technologies J-BERT N4903, User Manual

Page: 30 / 434

Version=EPA 2.0
Format=Text
Description=This is a simple alternating pattern
Count=2
Length=96
Data=
01 02 03 04 10 20 40 80 ff 00 ff 00
Data=
01 02 03 04 10 20 40 80 ff 00 ff 00
Pattern Resolutions and Lengths
The Serial BERT has 32Mbits (8 MB) RAM for storing patterns. As
discussed in
“How the Serial BERT Generates Memory-Based Patterns”
on page 31 , all patterns are loaded into the RAM until a 512-bit
boundary is reached. If the pattern is an odd number of bits long, it is
loaded into the RAM 512 times. Because of the restricted memory space,
there are also restrictions to the pattern lengths.
For example, a user pattern that is 256,001bit bit long would have to be
loaded into the RAM 512 times to reach the 512-bit boundary. Such a
pattern would occupy more than 128 Mbits in the RAM.
The Serial BERT handles such patterns by rounding them off to the
nearest length that would fit in the memory. For the above example, the
length would be rounded off to 256,000 bits. This rounding-off factor is
known as the pattern's
resolution . The following table lists all pattern
resolutions.
Table 3
Pattern length (standard) Pattern length (alternate) Resolution
≤
64 kbit
≤
32 kbit 1 bit
> 64 kbit > 32 kbit 2 bit
> 128 kbit > 64 kbit 4 bit
> 256 kbit > 128 kbit 8 bit
> 512 kbit > 256 kbit 16 bit
> 1 Mbit > 512 kbit 32 bit
> 2 Mbit > 1 Mbit 64 bit
2
Setting up Patterns
30 Agilent J-BERT N4903 High-Performance Serial BERT
Alternating Pattern in Text