Comment

Comment by jeff_ciesielski

I hate to give an 'it depends', but it depends.

Typically, no. In SPI all lines are actively driven high or low rather than an open drain configuration. The bus master drives SCK (SPI clock), MOSI (master out, slave in) and CS (chip select), and the slave device(s) drive the MISO (master in, slave out) line(s). From an operating perspective, pullup/pulldown resistors are not required.

Now having said that, in some cases it's considered appropriate to add weak pullup/pulldown resistors to the data lines to ensure that they're in the expected state on power up and to prevent glitches from putting slave devices into weird states.

Discussion

Live from the official Hacker News API

A modern reader for Hacker News · SvelteKit + Skeleton