Date: Sat, 20 Jul 1996 08:45:56 -0400 (EDT) From: Ken Wong <wong@wong.rogerswave.ca> To: Bruce Evans <bde@zeta.org.au> Cc: E00114@vnet.atea.be, freebsd-hardware@FreeBSD.org Subject: Re: Multiple COM ports with same IRQ Message-ID: <Pine.BSF.3.91.960720084406.406A-100000@wong.rogerswave.ca> In-Reply-To: <199607190254.MAA30468@godzilla.zeta.org.au>
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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
>
>
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