Re: [uCsimm] pulse detect

From: David Smead (
Date: Fri Nov 03 2000 - 20:19:26 EST

This is a straightforward application for IRQ.


David Smead

On Thu, 2 Nov 2000, James Wilson wrote:

> I want to detect a 0.5micro second pulse (STROBE) on
> the ucsimm?s PD0 port and, when this occurs, set a pin
> low (BUSY), then read 8 data pins on another port .
> At first I thought I could loop and wait for the pulse
> but the latency for the small bit of code I wrote was
> around 80microsecons way tooooo long for my
> application. Could anyone suggest a better way to
> do this? I have the following ideas but I'm not
> sure which one would be the easiest to implement.
> 1. Use a machine language subroutine to monitor the
> port
> 2. Use interrupt INT0 .
> 3. Use interrupt INT0 as in (2) but mask the interrupt
> and loop checking the interrupt pending register for
> any change.
> This message resent by the list server

This message resent by the list server

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