Stephen:
I cannot speak directly to the ADuC841 but it is unlikely that it is absolutely necessary that you use the DMA feature. The DMA feature is put on these A/D converters so that it is possible to perform several types of special operations with the converter. One of these is to operate the A/D at its highest speed which may not be possible with certain types of software implementations. The other purpose for DMA use is to permit a timer derived sampling/conversion rate for the A/D which is predictably periodic . General software that operates an A/D converter in polled mode invariably introduces a jitter in the sampling rate of the converter. This jitter can show up as error in the converter output data if that data is analyzed, particularly in something like an FFT or digital filter.

You can certainly simply read the ADC0 data register to get the results of the conversion as long as the conversion result is 8-bits wide. If it is a wider A/D converter then there would be more bits than just the 8 to read.

Also keep in mind that you will not be able to just simply read the ADC0 register free-wheeling in a loop. It will be necessary to condition each read on the ADC status bits that say that the previously commanded conversion is complete.

Michael Karas