Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!ucsd!ucsdhub!esosun!seismo!uunet!pcrat!rick From: rick@pcrat.UUCP (Rick Richardson) Newsgroups: comp.unix.microport Subject: Re: serial ports on the '286 Keywords: uport SV/286 Message-ID: <554@pcrat.UUCP> Date: 13 Aug 88 16:06:06 GMT References: <531@micropen> <4690@b-tech.UUCP> <5909@bigtex.uucp> <532@micropen> Reply-To: rick@pcrat.UUCP (Rick Richardson) Organization: PC Research, Inc., Tinton Falls, NJ Lines: 24 In article <532@micropen> dave@micropen (David F. Carlson) writes: >> For example, let's suppose uPort modified the serial driver such that >> when the line was put in raw mode, the 16550AN was set to generate an >> interrupt every tenth character. The interrupt handler would then get >But raw mode is defined (often) to return in *less* than 10 characters. >The "win" of the fifo is that overruns are nearly impossible, which allows >the driver to make interrupt latency almost a non-issue. Getting in and But the 16550A will automatically timeout and generate the interrupt for less than N characters if something is in the FIFO and it has been idle (I think) 4 character times. -- Rick Richardson, PC Research, Inc. (201) 542-3734 (voice, nights) OR (201) 389-8963 (voice, days) uunet!pcrat!rick (UUCP) rick%pcrat.uucp@uunet.uu.net (INTERNET)