Tektronix DG2030 User Manual page 47

Operating Basics
Pattern Data
Pattern data is the basic data that defines the digital signals to be output. The
pattern data is a collection of 8-bit words. The total number of words is called
the memory size. The memory size can be any value from a minimum of
90 words to a maximum of 256 K words (262,144).
Once pattern data has been transferred to the pattern memory in the pattern
generation unit hardware it can actually be output as digital signals. Pattern
memory consists of 8-bit words, with the 8 bits in a one-to-one correspondence
with the 8 output channels. The definition of the relationship between pattern
data bits and pattern memory bits is called output channel allocation.
The pattern data to pattern memory transfer operation is either performed
automatically each time the data is modified, or you can manually cause the
transfer to occur. This is called the data update mode, and it can be selected by
user.
Setup Data
There are a large number of settings that define data structures and relationships
between data items and that specify output channel states and other parameters.
These settings are collectively referred to as the setup data. Since this data is
associated with the pattern data, it is handled together with the pattern data in
operations such as saving instrument settings and data to a floppy disk.
The setup data includes a wide range of settings, including output voltage levels,
slope of edge, delay, high impedance control, clock frequency and PLL settings
in addition to the definitions described here.
Groups
Although each bit in the pattern data can be defined independently, it is easier to
edit and display data if multiple bits are collected and handled as a single group.
Any set of bits can be assigned as a group. However, the bits assigned to a group
must be adjacent to each other. For example, D0 through D3 can be assigned into
a group, but D0, D1, and D5 can not (D1 and D5 are not adjacent).
Blocks
Pattern data can be divided into blocks. A block is a user-specified range of
pattern data identified with a unique label. Blocks are divided by setting
delimiters called block delimiters. Block delimiters are set in word units.
Sequences, which are described later, control data output in block units.
2 12
DG2030 User Manual
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com