Allow developers to specify the (default) number of frames at compile
time (default to "off" as before). Accept the frame limit spec at scan()
time as well. This is useful when applications don't run config_set() at
runtime.
Tested with:
$ pulseview -d demo:logic_channels=0:analog_channels=1:limit_frames=4
The previous implementation supported the generation of frames as a
compile time option. This change lets users adjust the feature at
runtime.
In the absence of a frame count limit no frame begin/end markers get
sent (the default behaviour of the previous implementation). When a
frame count limit is specified, the respective number of frames gets
sent and acquisition stops.
The fixed amount of 1000 samples per frame is an arbitrary choice. This
compile time option is easily adjusted in the source code.
Introduce support for the "graycode" logic pattern. Generate up to
64 bits of graycode output (all logic lines, no repetition, not limited
by the generator's internal pattern buffer). The implementation was
tested with 16 channels.
Keep a context variable around with a bit mask for all logic channels.
This is convenient in setup and generation routines, to avoid garbage
in unassigned bit positions of session feed packets.
Move the declaration of codes for pattern types before the declaration
of the context container such that the latter can reference the former.
Add 'int' to an unsigned variable that omitted the base type.
A "low samplerate" in this case means anything where
samples_todo is less than SAMPLES_PER_FRAME. This case
wasn't handled properly before, resulting in wrong
amounts of data being sent out.
The previous implementation used to provide datafeed packets which
contain logic data in positions that correspond to disabled channels.
Do mask out logic data of disabled channels in the memory image before
it is sent to the session's datafeed. This implementation works fine for
those situations where either all logic channels are enabled (default
configuration) or when only the upper channels get disabled (which can
be considered a typical use case).
For those configurations where enabled channels follow disabled channels
(i.e. setups with gaps in the sequence of enabled channels) behaviour
will be unexpected: Neither is the mask adjusted to contain gaps, nor
will enabled channels get mapped to result in a dense representation.
The respective code paths are marked with TODO comments.
Add a comment to discuss a non-obvious generator call for analog data in
the acquisition start routine, while we are here.
The generator logic determines how many samples per group (analog and
logic) need to get produced, then keeps iterating until each group has
reached the specified count. Different groups can generate different
numbers of samples per iteration, they have their own stride.
It's essential to check whether all channels in a group are disabled, to
then completely skip the respective half of the generation loop. Without
this check, the group would be expected to generate data but it won't,
which results in an endless loop. This was observed with analog channels.
There was another issue with logic channels. Unexpected logic data was
seen in the output although neither logic channel was selected.
This commit fixes bug #923.
Skip the emission of session datafeed packets for disabled analog
channels.
Implementation detail: Allow for quick lookup of the channel that is
associated with an analog generator, as the data generation routines
only pass generator references in later calls.
This fixes part of bug #923 (which initially is about unexpected
logic data while analog channels were affected in similar ways).
Extend the demo driver, add another waveform choice for logic channels.
Create a "cable squid" logo representation which occupies a large number
of channels.
This pattern occupies 128x128 pixels. Unlike the 'sigrok' pattern it
gets repeated when more channels are involved, but is not shifted in the
repetition.