Newsgroups: comp.sys.transputer
From: roger@pact.srf.ac.uk (Roger Shepherd)
Subject: Re: One dumb question about DMA
Organization: University of Bristol, England
Date: Fri, 1 Jul 1994 16:35:51 GMT
Message-ID: <Cs9srs.6E0@info.bris.ac.uk>

Warren Day (wgd@ukc.ac.uk) wrote:

: How does it work in the more complex case where the two different priorities
: communicate between themselves in an environment that consists of other
: high priority communications?  For example,

:    PRI PAR
:      PAR
:        link ? array1
:        onchip ? array2
:      onchip ! array3


Communication on-chip, between two processes of different priorities
happens to take place at the priority of the second process which 
executes an input or output instruction.

: What happens if the outside world is immediately available to complete the
: communication, does it have priority?  What happens if the on-chip transfer
: is started and then the first byte arrives at the link?

Prioritisation occurs as defined above.

--
Roger Shepherd

Email: roger@inmos.co.uk
Mail : 10 Priory Road, Clifton, Bristol, BS8 1TU. UK.
Phone: +44 272 707 189, Fax +44 272 707 171.


