(parse_contents): Do not call sr_dbg() on every signal change.
This would be excessive even for sr_spew().
(read_until): Do not call ftell() just to be able to show some
number in a debug message later on.
These commands are superfluous and do not seem to make sense in
the context they were used. Also, $dumpvars was missing an $end,
and $dumpoff was used without any content.
Avoid writing a new timestamp for every changed signal if multiple
signals change state simultaneously. Also, keep signal transitions
on the same line with their timestamp to make the output easier to
inspect in a text editor. (VCD does not care whether newlines or
spaces are used to separate tokens.)
(receive): Use probe index for sample byte selection too, not just
for bit selection. Also simplify the indexing expressions a bit.
This fixes the problem of incorrect output for probes indices 8 to
31.
Also, use double rather than float in the timestamp calculation,
and format the result directly as floating point number rather than
converting it back to uint64_t.
Additionally, make sure that the state of all signals is written
for the very first sample in the stream. This fixes the problem
that signals would be displayed as indeterminate until the first
change.
(context.samplecount): Make the sample counter part of the context
struct, rather than keeping it as a global static.
Allow the edge of an external clock input to be configured by
means of an SR_CONF_CLOCK_EDGE configuration setting. This is
a string option with the same format as SR_CONF_TRIGGER_SLOPE.
Implement the configuration setting TRIGGER_SOURCE with the
choices CH (logic channels) and TRG (external trigger input).
Also implement the TRIGGER_SLOPE setting for selecting the
edge to trigger on (rising or falling).
It turns out that all LWLA protocol responses consist either
of 32-bit units or of 32-bit units combined into 64-bit units.
Thus it makes sense to double the basic unit size for reading
from 16 bit to 32 bit.
We cannot do the same for command messages though, as those
actually do use 16-bit quantities in some places, and 32-bit
arguments are not always aligned to 32-bit boundaries.
(acquisition_state.xfer_buf_in): Change unit type to uint32_t,
and update related macros and code accordingly.
(LWLA_TO_UINT32): New macro to replace LWLA_READ32, operating
directly on 32-bit values instead of pointers to 16-bit units.
Make use of a compiler-recognized idiom for bitwise rotation
to efficiently swap the 16-bit halves of a 32-bit word.
(LWLA_TO_UINT16): New macro to replace LWLA_READ16.
(LWLA_READ64): Remove unused macro.
(LWLA_WORD_[0123]): Slightly simplify 16-bit word extraction.