From owner-freebsd-hardware Sat Jul 20 05:47:40 1996 Return-Path: owner-hardware Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id FAA13724 for hardware-outgoing; Sat, 20 Jul 1996 05:47:40 -0700 (PDT) Received: from wong.rogerswave.ca (a17b32.rogerswave.ca [204.92.17.32]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id FAA13713 for ; Sat, 20 Jul 1996 05:47:38 -0700 (PDT) Received: (from wong@localhost) by wong.rogerswave.ca (8.7.5/8.7.3) id IAA00461; Sat, 20 Jul 1996 08:45:56 -0400 (EDT) Date: Sat, 20 Jul 1996 08:45:56 -0400 (EDT) From: Ken Wong To: Bruce Evans cc: E00114@vnet.atea.be, freebsd-hardware@FreeBSD.org Subject: Re: Multiple COM ports with same IRQ In-Reply-To: <199607190254.MAA30468@godzilla.zeta.org.au> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-hardware@FreeBSD.org X-Loop: FreeBSD.org Precedence: bulk On Fri, 19 Jul 1996, Bruce Evans wrote: > >Considering the UARTS will generate edge interrupt rather than level, will > >this work? Will sio grab the "dual port" interrupt then interrogate the > >individual status regs of the UARTS? I'm not too concerned with operation > >under DOS here, so I'm only concerned with FBSD. > > 16550 UARTs just generate signals that should work with either level or > edge sensitive schemes. If the interrupts are still edge sensitive from > the 8259 PIC's point of view, then they can't be shared. ^^^^^^^^^ I thought all 8259 PIC can be programmed to use either edge or level. anyway at least mine said it does. Ken > > Bruce > >