It seems that the cpu has a internal pull up on the MISO.
Is this true?
* Is it safe to assume external pullup is not needed?
* Is this documented anywhere?
Which port is your MISO coming from? MISOs can found on ports P, M, S and H. Ports P and S have pullups enabled out of reset. M and H not. See corresponding pull device enable register description (PERP, PERM, PERS, PERH).
Table 1-10 summarises if and how each pin is pulled out of reset.
I did not realize that the pull ups enabled from reset stayed that way after setting up the port for SPI.
I incorrectly assumed that the setup available before configuring för SPI would be changed to "SPI-mode".
My first SPI uses port S, and seems to have a pullup, which you have now confirmed.
My second SPI is on port H, and has no pullup.
Is it a reasonably safe assumption that that pullups, drive capabilty and other configured port parameters
will remain unchanged regardless of which internal I/O module the port later is configured for?
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