[Simulavr-devel] [Bug] VCD trace of PINx register not updated

[panic]

Hi list,

the PINx (e.g. PINB, PIND, ...) register holds the input state of the
port pins. This is independent of the DDRx settings.
The register itself is simulated/updated, but not so the VCD trace.

See the attached example that toggles PB1. Compile with

> avr-gcc -g -mmcu=atmega644 -std=gnu11 -O2 -Wall -Wextra -Werror -o 
> pinx-not-traced.elf pinx-not-traced.c

and run simulavr like so

> simulavr --device atmega644 --file pinx-not-traced.elf --terminate exit -c 
> vcd:tracein.txt:pinx-not-traced.vcd

For convenience, I've attached GTKWave screenshots with the bug ("fail")
and with the fix ("pass"). (Other pins being read as '1' is fine because
they are floating/output stage is in tristate, which is converted to '1'
after the simulated/implied Schmitt-trigger)

The fix is a one line change updating the tracer of the PINx register,
see the attached patch file.

(There are more bugs in HWPort and related to the PINx register, and
I'll create separate bug reports for them. This patch is a prerequesite
for the others patches though.)

Cheers,
panic

0001-update-PINx-tracer-on-portpin-update.patch
Description: Text Data

pinx-not-traced.c
Description: Text Data

pinx-not-traced_fail.png
Description: PNG image

pinx-not-traced_fail.vcd
Description: application/vnd.gtkwave-vcd

pinx-not-traced_pass.png
Description: PNG image

pinx-not-traced_pass.vcd
Description: application/vnd.gtkwave-vcd

tracein.txt
Description: Text document