In SX Microcontrollers, SX/B Compiler and SX-Key Tool, sammishal wrote:

Mr. Gunther

Thank you again.

Please look at the other thread for one more issue.

I would really like to see the real Programme Counter on the SXSim (and IDE DEbug) .

I think in some cases it would make things a lot clearer (as we have seen in the case of RET/P/W).

I think that just seeing the PC($02) and STATUS($03) is not enough and even misleading in some cases.


I wish the designers of the SX gave us a break. This whole Subroutines being confined to the upper 256 12bit words
of memory is annoying and can lead to funny errors.

I understand from the above description of the MicroCode that they are limited but could they not just 
as esily have designed the memory to be 13bits instead of 12 (additional 4K bits not too expensive).
This way the MicroCode 4bits would not interfere with the 9th bit of the Call address.

Anyway even the mighty 80286 had paging issues. That is why my favourite Micros are the
Motorolla ones where memory is just one big array.

I like the Harvard architucture and how it facilitates one clock instructions, but that is only really a trick
since most instructions are not really one clock but due to the pipe line they appear to be so. And even then
there are many instructions that even with the pipe line trick still require multi cycles, and many instructions
are compound instructions.

The RISC and enhanced Von Neuman Micros with pipelines and multi pipelines can achieve  one clock
instructions and have many more REAL one clock instructions.

I use the 68HC12 and find it a lot easier to develop for. 

But I love the price/size/speed/ and functionality of the SX. That is why I will stick with it.

And Thanks to people like you (and Parallax) providing the tools and Knowhow,
it can be quite a viable Micro.


Thanks again

P.S. Please look at the other thread for a wish list for your next upgrade to your ABSOLUTELY
INDESPENSABLE SXSim.

Samuel

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