Mail Archives: djgpp/1999/08/18/03:19:26
From: | DavMac AT iname DOT com (Davin McCall)
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Newsgroups: | comp.os.msdos.djgpp
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Subject: | Re: COM port interrupts don't happen?
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Date: | Wed, 18 Aug 1999 03:29:24 GMT
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Organization: | Monash Uni
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Lines: | 33
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Distribution: | world
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Message-ID: | <37ba27c1.10349410@newsserver.cc.monash.edu.au>
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References: | <7pcqfj$flj AT tandem DOT CAM DOT ORG>
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To: | djgpp AT delorie DOT com
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DJ-Gateway: | from newsgroup comp.os.msdos.djgpp
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Reply-To: | djgpp AT delorie DOT com
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You have to enable the UART chip to send interrupts.
IER (interrupt enable register) at 3F9h, 2F9h etc
bit 0 : 1 = enable recieved data available interrupt
bit 1 : 1 = enable transmitter holding register empty interrupt
bit 2 : 1 = enable reciver line status change interrupt
bit 3 : 1 = enable modem status change interrupt
Davin.
On Tue, 17 Aug 1999 19:15:42 -0400, "Martin Peach" <martin AT loplop DOT com>
wrote:
>I'm trying to process received characters from COM1. I have set up the UART
>and can receive OK by polling the device. I have set up a protected-mode
>interrupt routine which works fine if I assign INT0 (timer) interrupt to it.
>When I assign IRQ4 (INT0x0C, COM1) to it, nothing happens.
>The interrupt identification register says there is an interrupt pending
>when I poll it, the PIC mask has the corresponding bit cleared, the CPU ints
>are enabled using enable(), but my service routine is never called.
>Is this normal? I've tried this on a 486 and a pentium machine with
>identical results.
>What am I missing here?
>
>\/\/\/*= Martin
>
>
__________________________________________________________
*** davmac - sharkin'!! davmac AT iname DOT com ***
my programming page: http://yoyo.cc.monash.edu.au/~davmac/
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