Sign in

username:

password:



Not a member?

Search fpga-cpu



Search tips

Subscribe to fpga-cpu



fpga-cpu by Keywords

Altera | CISCifying | IDE | ISA | Java | JHDL | JTAG | LBU | MicroBlaze | PAR | PCI | RISC | SoC | Spartan | Transputers | Verilog | VHDL | Virtex | VLIW | WebPack | Xilinx | Xsoc | YARD-1A


Ads

Discussion Groups

See Also

DSPFPGAElectronics

Discussion Groups | FPGA-CPU | async SRAM writes

This list is for discussion of the design and implementation of field-programmable gate array based processors and integrated systems. It is also for discussion and community support of the XSOC Project (see http://www.fpgacpu.org/xsoc).

async SRAM writes - Jan Gray - Oct 22 23:55:00 2004

> I must have missed the part in the datasheet dealing with asymetric
> timing of read versus write. I have to get back into this as it may
> turn out that my system is working, but just because it is slow.
> But this is the second time I have seen refereces to multi-clock
> timing of writes. I have been treating it like a plain, vanilla,
> static ram, 2102 style. OOPS!

You might take a closer look at the (too clever by half) write handling in
the XSOC design (p. 19 in http://fpgacpu.org/papers/xsoc-series-drafts.pdf),
where we use three clock cycles (six clock edges) to perform two writes into
an async SRAM.

Jan Gray





(You need to be a member of fpga-cpu -- send a blank email to fpga-cpu-subscribe@yahoogroups.com )


Re: async SRAM writes - rtstofer - Oct 23 3:45:00 2004


Jan,

When I read through your project I was blown away by the elegance of
the design. I had tumbled to some of the concepts but I felt it
would be a while before I could grasp the entire project. There's
just a lot of great ideas. And porting the C compiler was a nice
touch - it prompted me to part with the money to buy the book.

But, frankly, another RISC or CISC machine didn't really interest me
as a project I wanted to build - I can buy one. For nearly 25 years
I have had the idea that I wanted to build a Pascal machine. Now
that I am retired I have the time to pursue the project and the FPGA
technology makes it possible. If I just have enough brains cells
left after all these years...

And I intend to build an IBM 1130 at some point. I have wanted to
do that for 35 years and I had better get it done soon. I don't
think a fellow ever forgets his first girl friend or his first
computer. I'm still excited about the computer...

Richard
--- In , "Jan Gray" <jsgray@a...> wrote:
> > I must have missed the part in the datasheet dealing with
asymetric
> > timing of read versus write. I have to get back into this as it
may
> > turn out that my system is working, but just because it is slow.
> > But this is the second time I have seen refereces to multi-clock
> > timing of writes. I have been treating it like a plain, vanilla,
> > static ram, 2102 style. OOPS!
>
> You might take a closer look at the (too clever by half) write
handling in
> the XSOC design (p. 19 in http://fpgacpu.org/papers/xsoc-series-
drafts.pdf),
> where we use three clock cycles (six clock edges) to perform two
writes into
> an async SRAM.
>
> Jan Gray





(You need to be a member of fpga-cpu -- send a blank email to fpga-cpu-subscribe@yahoogroups.com )