pat_gen :
A digital pattern generator
The pat_gen
primitive generates a stream of digital data pattern to an xbit-typed output. In other words, the primitive sequentially outputs each bit defined in the array parameter data
when triggered by the input trig
. The parameter trig_mode
defines whether the primitive is triggered by the positive edge (1), negative edge (-1), or both edges (0) of the input trig
(default: 1).
The data pattern can be repeated over time as a whole or in part. The parameters repeat_pos
and repeat_num
define this repetition behavior. For instance, if the parameter repeat_pos
is 3 and repeat_num
is 2 for the data pattern data
of ‘{1,0,0,1,1,0}, the output bit sequence is:
1-0-0-1-1-0-1-1-0-1-1-0 ^ ^ | | | +-- second repetition starting from data[3] +-- first repetition starting from data[3]
If the repeat_num
value is -1, the pattern will be repeated indefinitely.
When the parameter filename
is defined, the primitive reads in the named file that defines the parameter values in Python format. For example, the content of a parameter file corresponding to the above case would be:
data = [ 1, 0, 0, 1, 1, 0 ] repeat_pos = 3 repeat_num = 2
Input/Output Terminals
Name | I/O | Type | Description |
out | output | xbit | signal output |
trig | input | xbit | trigger input |
Parameters
Name | Type | Default | Unit | Description |
data | bit array | ‘{0} | None | data pattern |
repeat_pos | int | 0 | None | repetition start position |
repeat_num | int | 0 | None | number of repetitions |
trig_mode | int | 1 | None | triggering mode |
filename | string | “” | None | parameter definition file |