Re: [Simulavr-devel] A serial console utility

[Klaus Rudolph]

Robin Randhawa schrieb:

> Greetings.
>
> In the absence of any hardware (just my trusty debian box), I need to
> create an execution environment for some lightweight threads on an Atmel
> Atmega128 core. 
>
> I intend using avr-gdb with the remote gdb stub (gdbserver)
> implementation in simulavr(xx).
>
> As such I have the following questions:
>
> 1. Is the Atmega128 core supported by simulavr(xx) to the extent that
> the instruction decoder is comfortable with all the documented
> instructions ?
>  
Nearly all :-)
Writing to Flash (SPM instruction) is not implemented until now. So you 
are not able
to test any "bootcore" applications. But if needed I can put that stuff 
in the next days. :-)

The TWI is also not supported, and the USART it is not supported, it is 
only a UART like in
8515. If you need a synchronous U"S"ART I have to spend some days for 
it. And in Timers
I have no support for the second clock input (mostly used for RTC 
applications). The rest should
be complete.

> 2. I need the ability to send diagnostic text messages over the serial
> port. The need is only for a uni-directional text stream. Can
> simulavr(xx) render the data being sent to the UART on a tty (for
> example) ?
Yes, you can simply use a pipe to the os which enable you to give the 
data to a simple
terminal program. Also you can use the gui environment (tcl/tk) which 
give you
an edit window where the output can be seen. Also you have a second edit 
window
where you can type in chars which will be send to the avr uart if the 
uart pseudo device
is connected to the corrosponding pins. You are also able to build a 
software uart and connect
via any pin you want. The pseudo uart device is nothing more then a char 
to bitstream converter
which runs as external device and could be connected to any pin on the 
avr or other
simulated objects.


> It seems that Ken Restivo had come up with a framework for a
> tty based solution earlier but I don't think his patch has been
> incorporated, or has it ? Can someone suggest another solution ?
>
>  

Don´t know it and don´t need it :-) In addition there is a pseudo port 
usable which also could
be piped to a tty. It uses a non used IO-register in the IO memory 
region. All you need is to
write on that port. Look for "at90s8515special" core, this solution 
could be added to mega128 with
some lines of code by copy and paste.

> 3. I will be using almost the entire 64K of external data memory. Does
> the memory simulation recognise the external memory that the atmega128
> is capable of using ?
>  

Yes, you can use external RAM. Actually the ext ram is enabled every 
time which is not correct!
The corrosponding flags in MCUCR is not used... So the timing could be 
not correct if additional
wait states are needed. This is on my ToDo list. If you require totall 
acurate timing for external ram
excess please give me a note.

If you find any bugs or need some support please send me an email :-)

All I wrote is only valid for the simulavrxx. I have not used simulavr 
for more than a year.

Bye
  Klaus