From: mia Newsgroups: comp.sys.transputer Subject: Re: transputers and interrupt processing Date: Sun, 13 Dec 1998 09:54:57 +0200 Organization: nice Message-Id: <367372D1.56B0@nice.com> References: <74o7v6$517$1@andromeda.camcon.co.uk> Reply-To: mia@nice.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Pali Surdhar wrote: > > For the transputer buffs out there - I'm wondering if anyone can tell me > about I/O interrupt processing on the T805. How quick can interrupts be > processed and is there any way to configure interrupt handling. > > I have an application that uses a data aquisition card that samples at 16 > microseconds, but for some reason data only squirts out on the transputer at > 200 microseconds - is this an interrupt related problem or am I barking up > the wrong tree? > > Any insight will be greatly appreciated, > > Confused research student. hi confused, transputer task switching is VERY fast - 15 usec. however if you do something more than just raise a flag in your interrupt handler then 200usec will might cause trouble. also, interrupt handlers are considered priority "high". there are only 2 priority levels in the transputer, and if your other tasks are also "high" they will surely interfere with your timing. moreover, if you send a message to a "high" task, it will do the execution f the "other" task first, which means you dont get to release the interrupt til it finishes (if you send to a "low" task, just the message is sent and execution resumes in the "high" - interrupt handler- task). in short, read the book about priorities and be VERY brief in the interrupt handler. good luck Mia