FPGA Central

Hi, all.

Is it known to be possible to create a Microblaze system without the
OPB?

For example, say I have 1 MicroBlaze with 16KB of d&i BRAM, but I
don't necessarily need the off-chip SDRAM or UART (or any OPB slave
peripheral at all), so I don't include the OPB. And say it's part of a
larger network to justify not needing the OPB for any peripherals.

Currently, my 8.2 version has an issue with the BRAM when I don't
include the OPB, and gives me an error (ERROR:Mablib:482). I was
wondering if this is a problem with my particular system, or if it's a
universal requirement for MicroBlaze projects to include at least one
OPB slave. Or if it's a legitimate bug.

Thanks!

----JD----

JD Newcomb wrote:
> Hi, all.
>
> Is it known to be possible to create a Microblaze system without the
> OPB?
>
> For example, say I have 1 MicroBlaze with 16KB of d&i BRAM, but I
> don't necessarily need the off-chip SDRAM or UART (or any OPB slave
> peripheral at all), so I don't include the OPB. And say it's part of a
> larger network to justify not needing the OPB for any peripherals.
>
> Currently, my 8.2 version has an issue with the BRAM when I don't
> include the OPB, and gives me an error (ERROR:Mablib:482). I was
> wondering if this is a problem with my particular system, or if it's a
> universal requirement for MicroBlaze projects to include at least one
> OPB slave. Or if it's a legitimate bug.
>

It should be possible to create such a system. I've seen projects that
only have MicroBlaze + LMB + a peripheral on FSL.

-Siva

On Jul 25, 4:22 pm, Siva Velusamy <siva.velus...@xilinx.com> wrote:
> JD Newcomb wrote:
> > Hi, all.
>
> > Is it known to be possible to create a Microblaze system without the
> > OPB?
>
> > For example, say I have 1 MicroBlaze with 16KB of d&i BRAM, but I
> > don't necessarily need the off-chip SDRAM or UART (or any OPB slave
> > peripheral at all), so I don't include the OPB. And say it's part of a
> > larger network to justify not needing the OPB for any peripherals.
>
> > Currently, my 8.2 version has an issue with the BRAM when I don't
> > include the OPB, and gives me an error (ERROR:Mablib:482). I was
> > wondering if this is a problem with my particular system, or if it's a
> > universal requirement for MicroBlaze projects to include at least one
> > OPB slave. Or if it's a legitimate bug.
>
> It should be possible to create such a system. I've seen projects that
> only have MicroBlaze + LMB + a peripheral on FSL.
>
> -Siva

You don't need an OPB connection for the MicroBlaze to operate
properly. It's possible that the MicroBlaze can be connected only via
LMB (or XCL) and FSL. One possible system is using multiple
MicroBlazes as stream processors where data is pushed in via the FSL
to one MicroBlaze. This MB then performs some data calculation/
manipulation/etc then passes it to another MB via the FSL. This MB
could perform data repackaging, DMA chain creation, etc and then push
the data to another piece of hardware (internal or external), once
again via FSL.