Serial port interrupts?

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Serial port interrupts?

John Coppens
Hello people.

To make a debugging tool, I need to time changes on the serial port
control and status lines on a Linux machine. The serial port hardware has
this possibility, but is it possible to program this in a more
or less high-level way? I did this a long time ago in DOS.

I've looked at several libraries, but none seem to give access to
line/status change events in realtime.

Thanks in advance,
John
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Re: Serial port interrupts?

Tom Walsh-2
John Coppens wrote:

> Hello people.
>
> To make a debugging tool, I need to time changes on the serial port
> control and status lines on a Linux machine. The serial port hardware has
> this possibility, but is it possible to program this in a more
> or less high-level way? I did this a long time ago in DOS.
>
> I've looked at several libraries, but none seem to give access to
> line/status change events in realtime.
>
>  

I doubt that you could do the same with Windows XP.  Hardware operations
are abstracted such that the device is "managed" via a kernel device
driver.  To do what you want to do might require you to write / modify
the serial port driver.

Having said that, it would be doubtful as to how finite a measurement /
control that you could exert over the serial port.  Modern kernels are
multi-tasking beasts, and by design, no one process (thread) should /
could take up the full attention of the kernel for any significant
amount of time.  Even under an interrupt driven service there would be
jitter and an unpredictable response time before the service routine is
actually run.

TomW


--
Tom Walsh - WN3L - Embedded Systems Consultant
http://openhardware.net http://cyberiansoftware.com http://openzipit.org
"Windows? No thanks, I have work to do..."
----------------------------------------------------


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RE: Serial port interrupts?

dale.harris-2
Where can I find the rtl guide or documentation for the serial library.
I'm only using linux/unix
and since I don't want to recreate the wheel sort to speak I just need
details on how to use the
existing library.  Couldn't find anything about it in the current 2.2.x
dox. Thanks.


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-----Original Message-----
From: [hidden email]
[mailto:[hidden email]] On Behalf Of Tom Walsh
Sent: Wednesday, October 10, 2007 4:36 AM
To: FPC-Pascal users discussions
Subject: Re: [fpc-pascal] Serial port interrupts?

John Coppens wrote:

> Hello people.
>
> To make a debugging tool, I need to time changes on the serial port
> control and status lines on a Linux machine. The serial port hardware
> has this possibility, but is it possible to program this in a more or
> less high-level way? I did this a long time ago in DOS.
>
> I've looked at several libraries, but none seem to give access to
> line/status change events in realtime.
>
>  

I doubt that you could do the same with Windows XP.  Hardware operations
are abstracted such that the device is "managed" via a kernel device
driver.  To do what you want to do might require you to write / modify
the serial port driver.

Having said that, it would be doubtful as to how finite a measurement /
control that you could exert over the serial port.  Modern kernels are
multi-tasking beasts, and by design, no one process (thread) should /
could take up the full attention of the kernel for any significant
amount of time.  Even under an interrupt driven service there would be
jitter and an unpredictable response time before the service routine is
actually run.

TomW


--
Tom Walsh - WN3L - Embedded Systems Consultant http://openhardware.net
http://cyberiansoftware.com http://openzipit.org "Windows? No thanks, I
have work to do..."
----------------------------------------------------


_______________________________________________
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