Path: utzoo!utgpu!bnr-vpa!bruce
From: bruce@bnr-vpa.UUCP (Bruce Townsend)
Newsgroups: comp.sys.hp
Subject: Re: GPIO (AFI) Interface Problem with HP9000s825 R2.0
Message-ID: <106@bnr-vpa.UUCP>
Date: 9 Dec 88 14:48:17 GMT
References: <104@bnr-vpa.UUCP> <1310003@hpdstma.HP.COM>
Reply-To: bruce@bnr-vpa.UUCP (Bruce Townsend)
Organization: Bell-Northern Research, Ottawa, Ontario
Lines: 13

In article <1310003@hpdstma.HP.COM> dc@hpdstma.HP.COM (Daniel Cordey) writes:
>20 ms seems too long...Is your process runing at a real-time priority ?
>
	No; perhaps if it were, the gap could be reduced to 10ms? 5ms?
even 1ms?  That is still too long; the samples are presented/read by
the peripheral at a regular rate up to 100K words/sec.  That means that
the interval between any given pair of sample read/writes can be no longer
than 10 usec.  Clearly, continuous DMA into physical memory is required.

-- 
Bruce Townsend (bnr-vpa!bruce)	Phone:	(613) 763-3008
Bell-Northern Research		Usenet: {utzoo, utcs}!bnr-vpa!bruce
P.O. Box 3511, Station C, Ottawa, Ontario, Canada, K1Y 4H7