FPGA Central

Now I want to design a RISC cpu for study the cpu architecture, and I
am puzzled about how to start?
Whether should I start with a RISC 16 bit cpu, including just serveral
instructions like add, substract, multiply and divide?
And I wonder whether I should introduce the pipeline and superscalar
into the architecture?

[email protected] wrote:
> Now I want to design a RISC cpu for study the cpu architecture, and I
> am puzzled about how to start?

Try reading about the DLX and looking at the code for the OpenRISC.

> Whether should I start with a RISC 16 bit cpu, including just serveral
> instructions like add, substract, multiply and divide?

This is usually a good starting point.

> And I wonder whether I should introduce the pipeline and superscalar
> into the architecture?

It's not really a RISC if it's not pipelined. I'd save superscalar for
another day, if this is your first effort.

Cheers,
Jon

[email protected] wrote:
> Now I want to design a RISC cpu for study the cpu architecture, and I
> am puzzled about how to start?
> Whether should I start with a RISC 16 bit cpu, including just serveral
> instructions like add, substract, multiply and divide?
> And I wonder whether I should introduce the pipeline and superscalar
> into the architecture?

The Lattice Mico8 is open source, & FPGA optimised, so makes a good
starting point - and you are free to move it to any fabric, or extend it.
It is also quite similar to the PicoBlaze. (which is not open source?)

-jg

Hi,

PicoBlaze is open source. MicroBlaze is not.

JaaC

Is There any recommended book which includes RISC cpu examples for me
to start with?
I think follow with samples is more efficient.

On 5 Jan 2006 06:36:39 -0800, "[email protected]" <[email protected]> wrote:
>Now I want to design a RISC cpu for study the cpu architecture, and I
>am puzzled about how to start?
>Whether should I start with a RISC 16 bit cpu, including just serveral
>instructions like add, substract, multiply and divide?
>And I wonder whether I should introduce the pipeline and superscalar
>into the architecture?

The best place for you to start is http://www.fpgacpu.org/xsoc/cc.html

Enjoy!!


Philip

Philip Freidin
Fliptronics