Re: Is XIRQ level or edge sensitive?

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Re: Is XIRQ level or edge sensitive?

Doron Fael
Steve,

As far as I know the XIRQ interrupt is level sensitive, and cannot be
configured to edge sensitive.

In any case, usually the XIRQ does not need to be edge sensitive, since it
has a higher priority than all other interrupts, and is also not masked
when other interrupts are masked. this is since the XIRQ interrupt depends
on the CCR register "X" interrupt mask bit, rather than the CCR register
"I" interrupt mask bit (The "X" bit does not change when you code processes
a normal "I" bit interrupt, so once the XIRQ interrupt is enabled using the
CCR register "X" bit, the XIRQ interrupts are always enabled - until the
next Reset).

Hope this helps,
Doron
Nohau
HC12 In-Circuit Emulators
www.nohau.com/emul12pc.html


At 18:43 08/04/2005 -0500, you wrote:

>I have looked thru the documentation until I am frustrated.
>Does anyone know if the XIRQ pin is level sensitive or edge sensitive by
>default?
>Can XIRQ be modified to edge sensitive like the IRQ pin?  If so, which
>register modifies this?
>
>Regards,
>
>Steve Dillier
>
>HighPoint Design LLC


[Non-text portions of this message have been removed]



 
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Re: Is XIRQ level or edge sensitive?

melstav
Nope.  ~XIRQ is strictly level-senitive, and cannot be reversed.
A logic 0 will always trigger the interrupt if it's enabled.

>   Date: Thu, 09 Jun 2005 10:38:11 +0300
>   From: Doron Fael <[hidden email]>
> Subject: Re: Is XIRQ level or edge sensitive?
>
> Steve,
>
> As far as I know the XIRQ interrupt is level sensitive, and cannot be
> configured to edge sensitive.
>
> In any case, usually the XIRQ does not need to be edge sensitive, since it
> has a higher priority than all other interrupts, and is also not masked
> when other interrupts are masked. this is since the XIRQ interrupt depends
> on the CCR register "X" interrupt mask bit, rather than the CCR register
> "I" interrupt mask bit (The "X" bit does not change when you code
> processes
> a normal "I" bit interrupt, so once the XIRQ interrupt is enabled using
> the
> CCR register "X" bit, the XIRQ interrupts are always enabled - until the
> next Reset).
>
> Hope this helps,
> Doron
> Nohau
> HC12 In-Circuit Emulators
> www.nohau.com/emul12pc.html
>
>
> At 18:43 08/04/2005 -0500, you wrote:
>>I have looked thru the documentation until I am frustrated.
>>Does anyone know if the XIRQ pin is level sensitive or edge sensitive by
>>default?
>>Can XIRQ be modified to edge sensitive like the IRQ pin?  If so, which
>>register modifies this?
>>
>>Regards,
>>
>>Steve Dillier
>>
>>HighPoint Design LLC
>
>
> [Non-text portions of this message have been removed]
>
>
>
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