Configuring Reference to an ADC in PSoC1

Question: What are the different reference voltages that can be selected for an ADC measurement?  Is it possible to configure an ADC to take an external reference?



The reference to an ADC (and other analog sections) may be selected using the "Ref Mux" parameter in the Global Resources.

Following are the various reference settings available in a PSoC with full function Analog blocks.

1.       (Vcc/2)+/- bandgap

2.       (VCC/2) +/- Vcc/2

3.       Bandgap +/- Bandgap

4.       (1.6 Bandgap) +/- (1.6 Bandgap)

5.       (2*Bandgap) +/- Bandgap

6.       (2*Bandgap) +/- P2[6]

7.       P2[4] +/- Bandgap

8.       P2[4] +/- P2[6]

Using options 7 and 8, an external voltage source may be used as AGND or Reference.

Note: The Reference selected using the RefMux parameter is common to all the analog blocks.