fungus:
MarkT:
No, 7 resistors and 0V and Vcc are among the valid 8 voltages. Fig 1-3 in datasheet.Yes they are, but the allowed range for the first/last rows in the table is bigger.
Think though: With 7 resistors the first voltage in your chain would be 1/7 VDD.
At VDD=5.5 that's 0.7857V - nowhere near any of the target voltages in figure 1.3 (column V2).
Ah yes, that's odd, I'd have thought they would choose the on-chip resistors appropriate to allow equal external resistors (chip designers usually think carefully about the parts count on external circuit). So you need the two end resistors to be 3/2 the size of the other 5. Or use 9, make the end ones 1/2 the value of the others, and ignore the first and last taps.
Still with 1% resistors 7 equal value ones would actually work I think, on-chip resistors have very good matching.