Date:	Wed, 18 Aug 1999 15:29:52 +0300 (IDT)
From:	Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
X-Sender:	eliz AT is
To:	Martin Peach <martin AT loplop DOT com>
cc:	djgpp AT delorie DOT com
Subject:	Re: hardware ints
In-Reply-To:	<7p7h6g$o5i@tandem.CAM.ORG>
Message-ID:	<Pine.SUN.3.91.990818152505.10490Q-100000@is>
MIME-Version:	1.0
Reply-To:	djgpp AT delorie DOT com
X-Mailing-List:	djgpp AT delorie DOT com
X-Unsubscribes-To:	listserv AT delorie DOT com

On Sun, 15 Aug 1999, Martin Peach wrote:

> Although I enabled the receive character interrupt in the IER register of
> the UART and set the PIC interrupt mask, I am not sure if the UART is
> generating interrupts to the 8259 PIC. Is there a way to check for this?

One way of doing this would be to read the Interrupt Request Register and 
Interrupt In-Service Register of the PIC, and check whether the bit 
corresponding to IRQ3 is set.

> Is it OK to use a protected mode handler for the COM ports?

Yes.

> Is something else getting to my interrupts before I get there?

No, hardware interrupts are always sent to the protected-mode handler 
first.

- Raw text -