OPENCORES.ORG

I want to know if the ZPU instruction set is documented anywhere.

I get these email digests from this mailing lists a *LONG* time after
the post.... how often are digest emails sent out?

anway...

I listen more closely to this mailing list. I've answered a number of
emails privately in email, but I'm considering only replying
to emails at the zylin-zpu mailing list...

http://mail.zylin.com/mailman/listinfo/zylin-zpu_zylin.com

>  I want to know if the ZPU instruction set is documented anywhere.

There are only 11 instructions :-) and there is some documentation
here:

http://www.opencores.org/cvsweb.shtml/zpu/zpu/docs/zpuprotoarch.odt

- addsp is missing
- pushpc is emulated (or implement in hw as the case may be)

Patches welcome!

> I
>  managed to synthesize the core and have compiled a very simple test
>  program but I cannot get it to run. If I understood a little more about
>  what the opcodes did, I could figure out what I am doing wrong.

You can enable trace output, which shows what instructions are executed.

I've recently checked in some fixes to hdl/examples.

The ZPU really does work, but what I committed to opencores was not
precisely the same as what i worked on, so some of the examples
and modelsim demos, etc. stopped working. I had to leave a few
things out to fit the open source license.

> Maybe
>  this is an endian-ness issue but I can't tell.

It's a big-endian architecture as far as I recall.

>
>  Here is my simple example. I am running Cygwin on Windows XP.
>
>  $ cat looptest.c
>  // Dead simple test program
>  main()
>  {
>     while(1)
>         ;
>  }
>
>  $ zpu-elf-gcc -o looptest.elf looptest.c -nostartfiles

-nostartfiles leaves out the microcode! :-)

>  /home/Adam/zpu/bin/../lib/gcc/zpu-elf/3.4.2/../../../../zpu-elf/bin/ld: warning:
>   cannot find entry symbol _start; defaulting to 00000000
>
>  $ zpu-elf-objcopy -O binary looptest.elf looptest.bin

To show disassembly:

zpu-elf-objdump --disassemble looptest.elf

To show all sections, including microcode:

zpu-elf-objdump --disassemble-all looptest.elf

>  $ hexdump looptest.bin
>  0000000 088c 8c02 0b0c 0b0b fb0b 0039
>  000000b
>
>  $ java -classpath zpu/simulator/zpusim.jar com.zylin.zpu.simulator.tools.MakeRam looptest.bin
>  0 => x"8c08028c",
>  1 => x"0c0b0b0b",
>

Answering second email from digest...

>  I've got another step further, I noticed that the Java "MakeRam" utility
>  tends to leave a few bytes off the end. I'm not much of a Java person so
>  I re-wrote it in C. Here it is. You could include it in the ZPU CVS if
>  you think it useful.

Thanks! Committed:

2008-03-06 Adam Pierce
	* zpu/zpu/hdl/example/zpuromgen.c - generate rom files
	  without java

-- 
Øyvind Harboe
http://www.zylin.com - eCos ARM & FPGA  developer kit