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Discussion Groups | LPC900 | Application Hint LPC935 ADC with Zero interrupt load
Find help, specifications and source code for the LPC900. The LPC900 challenges Microchip and AVR based on the worlds most popular 8-bit architecture the 80C51. With a 2-clock core the LPC900 series is a high performance, very flexible and low cost 8-bit microcontroller family. Designers using or interested in these devices are encouraged to share their know-how and ask questions.
Application Hint LPC935 ADC with Zero interrupt load - philips_apps - Jul 27 20:50:00 2004
Hi,
there is a great feature in the LPC935 ADC which could change the way
you do analog to digital conversions. Every input (channel) has a
dedicated result register. Also the ADC offers a scan mode, you select
which channel are to be converted, start the ADC and all the selected
channels are converted. To make this feature even more powerful, there
is an Autoscan Continous Conversion mode that keeps repeating the
conversions until the user stops it. Using this mode and considering
that the ADC is good for 200k samples / sec, you can keep the ADC
converting all the time the channels you want to use.
If you need the digital value that has been sampled last, you can
depend on the fact that this value is no older than 20 us! Most other
ADCs on comparable 8-bit microcontrollers on the market need 20 us
conversion time to begin with. So, the value is ready and available
whenever you need it, no need to handle interrupts, just go and read
the value.
We think this is a great feature :-)
Cheers, Robert
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )
there is a great feature in the LPC935 ADC which could change the way
you do analog to digital conversions. Every input (channel) has a
dedicated result register. Also the ADC offers a scan mode, you select
which channel are to be converted, start the ADC and all the selected
channels are converted. To make this feature even more powerful, there
is an Autoscan Continous Conversion mode that keeps repeating the
conversions until the user stops it. Using this mode and considering
that the ADC is good for 200k samples / sec, you can keep the ADC
converting all the time the channels you want to use.
If you need the digital value that has been sampled last, you can
depend on the fact that this value is no older than 20 us! Most other
ADCs on comparable 8-bit microcontrollers on the market need 20 us
conversion time to begin with. So, the value is ready and available
whenever you need it, no need to handle interrupts, just go and read
the value.
We think this is a great feature :-)
Cheers, Robert
(You need to be a member of LPC900_users -- send a blank email to LPC900_users-subscribe@yahoogroups.com )