Hi support team,
There are three 2.2Kohm pull-up resistors connected on the LPC55S69 SPI interface in our LPC55S69 EVB.
Would like to ask why it needs these pull-up R for a SPI bus which has no pull-up R in general.
Are these R necessary ? Are our SPI pins(SPI_MISO, SPI_MOSI, SPI_SSEL) open-drain and must pull high externally ? or transmission speed concern.