[Oberon] SRAM vs. BRAM

[greim]

Hallo Bernhard,

i have got some days ago the
Pipistrello Spartan6 board + the Oberon "Wing"( SRAM, keyboard + Mouse 
connector, HDMI interface instead of VGA)

See
<http://saanlima.com/forum/viewtopic.php?f=4&t=1246&start=8>

After some fiddling with the Linux dd command for writing a micro SD 
card it runs really out of the box!

Magnus, the HW and Verilog designer did really a great job!

All the design is OpenSource!

In his forum he explained why a real HW SRAM is better then using the 
DRAM here:

cite..
...
Yes. I totally agree and that's the approach I started with. However, 
while it's quite simple to add the code for the MCB block you definitely 
need a cache between the memory controller and the Risc5 cpu, and the 
size and complexity of that code is probably greater than all of the 
Oberon verilog code together depending on what performance level we target.

I felt that this was a step in the wrong direction since what I really 
like about the Oberon system is that it's so simple and easy to 
understand how it works, and this would add a bunch of fairly complex 
code. However, it there is interest in this approach then I could put it 
back on the front burner.

Magnus
....

The only modifications he has done with the Verilog code, was an 
extension / replacement of the VGA output.
So any volunteers to re-translate his (and Xilinxs..)  Verilog code back 
to LOLA2 ?

One critic or disadvantage is, that nearly all pins of the FPGA hase 
been eaten by the SRAM interface. But i guess we have some address space 
left for interfacing some I/Os like ADCs etc. The Oberon wing is quite 
simple, the EAGLE files are available, so this should be no real problem.

The Pipistrello board can also run Linux or Pacman or a Propeller 
processor etc. and the loading time for the configuration is impressing 
fast. And there is no special JTAG cable or similar required.

The price for the Pipistrello and the Oberon wing is about 200$.
Thats, compared with the Raspberry PI quite expensive, but we aren't 
talk about 5 Mio. pcs. here.

So the "hardware problem" is solved i think.
Time for some hard- and software extension to awake our prince..

Regards

Markus Greim