Hi all,
I have two questions regarding the OPB usage.
1) why is it the microblaze connects to the IOPB port to the OPB bus
when running from internal memory (BRAM) ? the program runs only from
the ILMB isn't it?
2) PLB-OPB bridge , the PPC405 reference guide says that the PLB should
be used for fast bus transactions and that the OPB is to be used for
slower peripherals (GPIOs/UART etc.). My question is as follows - If
I'm using a PLB-OPB bridge the data
from/to the OPB will still go trough the PLB bus so how come it is says

the the OPB usage takes some load of the PLB bus ? 
Thanks, Mordehay.

1>
I have written demos where microblaze accesses the ILMB without IOPB.
Where did you see this listed? Also, I have a demo with IOB without
ILMB. MB just needs to have memory at start address 0x0 either on IOPB
or ILMB. The ILMB is just faster since only 1 master is allowed thus
no bus arbitration therefore preferred.


m...@walla.co.il wrote:
> Hi all,
> I have two questions regarding the OPB usage.
> 1) why is it the microblaze connects to the IOPB port to the OPB bus
> when running from internal memory (BRAM) ? the program runs only from
> the ILMB isn't it?
> 2) PLB-OPB bridge , the PPC405 reference guide says that the PLB should
> be used for fast bus transactions and that the OPB is to be used for
> slower peripherals (GPIOs/UART etc.). My question is as follows - If
> I'm using a PLB-OPB bridge the data
> from/to the OPB will still go trough the PLB bus so how come it is says
> 
> the the OPB usage takes some load of the PLB bus ? 
> Thanks, Mordehay.
>