Why ADC1_DM1 multiplexing is "reserved" but works from example on K65?

[aureliengrange]

Hi everybody,

I have planned to use for a new board all 3 differentials ADC input of the K65.
At the beginning I hope to use each of differential signal as single one to get 6 single ADC input.

I have notice that the input ADC1_DP1 can be used both in single or differential mode, but the ADC1_DM1 (PIN M1 in TWR-K65F180M) is only available in differential mode.
As it seems strange, I used the "lawadc" example to test this pin (With ADC1 Channel AD20).
The example works perfectly so I read the reference Manuel and I see that this signal is “RESERVED”.

I would like to know if it is an errata or if there is a reason that the reference manual (p960 Rev3) indicates "Reserved"?

Thanks for your details.

[jorge_a_vazquez]

Hi

It is not a errata, as you can see in the note

Just certains ADC_DM inpust may operate as single ended, So this pin is named as reserved because it shouldn't works in single ended. I going to test this and if I find some strange behaviour I will inform to development team.

Thanks for the feedback.

Best Regards

Jorge Alcala

[aureliengrange]

Hi Jorge,

I have ever seen this in the reference manual.

It shouldn't work but I see the opposite from my test, it seems to works quite good.

Does it is possible that for commercial reason (to buy a chip more specific with more analog) this functionality is hidden behind the “RESERVED”?

Thanks for helping me.

Have a nice day.

Aurélien