Need help - SPI and internal pull-up

darko2 · ‎2016-10-08

Posted on October 08, 2016 at 22:46

Hi,

I use STM32L073 and configure SPI port. Problem is my slave device has SPI_MISO pin as open-drain, very uncommon. Question is if I configure MCU pin as SPI_MISO can I have also pull-up function on that pin or need external?

Darko

waclawek.jan · ‎2016-10-09

Posted on October 09, 2016 at 12:18

> Question is if I configure MCU pin as SPI_MISO can I have also pull-up function on that pin

Yes. However, the internal pull-up is relatively weak - check if the resulting RC (with the parasitic C of the MISO pins and tracks) is fast enough for your bitrate.

JW