Lpc2000

Hi Gus,

I use to capture pulses for measuring own-build semi-digital signals with 
different pulse-width and different periods to encoding information.
My lpc2129 is running at 14.7456 * 4 = 58.9824 MHz with Timer running at 
full speed, so I can capture 1/(58.9824*10^6) s resolution in time 
information,
that's about  17 ns resolution! ... and it really works
Don't know how you're capturing your signal? I capture on rising edge with 
interrupt and on falling edge without interrupt (same signal on two 
different pins). Inside interrupt routine, the values of both
capture-registers are read and compared with with each another and with 
the last value from one periode before; Since the timer is a 32 bit timer, 
the
maximum period is about 2^32 * resolution -> 73 seconds; to get a 
frequency range: 0.014 Hz to near 58.9824 MHz (hi)

Thomas


lpc2000@yahoogroups.com wrote on 08.08.2005 18:36:18:

> Hello,
> 
> What is the shortest pulse you can mesure on LPC capture module?
> 
> I am trying to measure some pulses using the capture hardware on LPC 
> chips. The processor is running at 48Mhz and my capture module is 
> running at 1us/ticks
> 
> Connecting a function generator, I can read valid results up to 1Khz. 
> When I go over 10KHz, the reading is not stable at all! About 10% up 
> and down.
> 
> Thanks,
> 
> Gus
> 
> 
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> 
> Yahoo! Groups Links
> 
> 
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> 
> 


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