>; CAVEAT below !!!!!!
>; you have to write the number of transfers before giving the
>; buffer address or it won't start transfers
>
> Guess in which order I tried to initialize the DTC - arhhg!
>
> After swapping the initialization of ADC10DTC0 and ADC10DTC1 everything
> is working as expected.
>
> Did you figured out this 'rule' by yourself or is this somehow
> documented ? I read the ADC10 chapter of the user guide over and over
> but I couldn't find anything like this - but after reading through this
> more than three times you get a kind of blind anyway ;-)
It's Evil... it's documented in the state transfer diagram,
figure 18-12 (and figure 18-10 for one-block mode).
Notice the three states "DTC reset", "DTC init" and "DTC idle".
First, notice the note by the "DTC reset" state documenting the
short alias "n" for the count register, ADC10DTC1.
To get from 1 to 2, you need to write the count register. Clearing
the count register resets the entire state machine.
To get from 2 to 3, you need to write the ADC10SA register.
On the way, it passes through the "x=n" bubble, where the count is
latched, so the value of the count register at the time you write
ADC10SA is what's going to be used for the first block.
The other hint is the description of ADC10SA:
ADC10SAx Bits ADC10 start address. These bits are the start address for the
DTC. A write
15-1 to register ADC10SA is required to initiate DTC transfers.
Unused Bit 0 Unused, Read only. Always read as 0.
Which is reminding you that writing to ADC10SA should be the last thing
you do.
