newbie Q, multiprocessor interconnect with bus

hi

Each processing node has its local memory and global memory to share.
Each processor and its local memory are connected with local bus. There
are also 'routing' issue and 'arbitration' issue.

then

'Is it possible to make MESH-interconnected on-chip 4 processors using
BUS ? '

It implicitly mean the interconnection between switches can be a
'bus'.....Maybe my knowledge is short to answer the following question

Thankyou for your remark for beginner

Elinore wrote:

> Each processing node has its local memory and global memory to share.
> Each processor and its local memory are connected with local bus. There
> are also 'routing' issue and 'arbitration' issue.
> 
> 'Is it possible to make MESH-interconnected on-chip 4 processors using
> BUS ? '
> 

What the heck are you trying to do? I'm trying to imagine a system that 
shares memory like this- it's asking for trouble IMHO.

I take it you mean its local memory is private, the global memory is shared.

It's certainly possible... no different conceptually from dual port RAM- 
everybody is isolated from the shared RAM by 3 state buffers, when you 
get your go on the shared area you control the address, data and control 
lines as normal.

As for arbitration, that depends on what you want to do. A simple system 
would just allow the first to grab the bus, and put everyone else on 
hold until the access is finished, then let the next have a go. Easy 
enough with DPR, with 4 on the go you'd have to queue the waiting 
processors.

Paul Burke