ADuC7019/20/21/22/24/25/26/27/28/29,pdf datasheet

The ADuC7019/20/21/22/24/25/26/27/28 are fully integrated,
1 MSPS, 12-bit data acquisition systems incorporating high
performance multichannel ADCs, 16-bit/32-bit MCUs, and
Flash/EE memory on a single chip.
The ADC consists of up to 12 single-ended inputs. An additional
four inputs are available but are multiplexed with the four DAC
output pins. The four DAC outputs are only available on certain
models (ADuC7020 and ADuC7026). However, in many cases
where the DAC outputs are not present, these pins can still be used
as additional ADC inputs, giving a maximum of 16 ADC input
channels. The ADC can operate in single-ended or differential
input modes. The ADC input voltage is 0 V to VREF. A low drift
band gap reference, temperature sensor, and voltage comparator
complete the ADC peripheral set.
Depending on the part model, up to four buffered voltage
output DACs are available on-chip. The DAC output range is
programmable to one of three voltage ranges.