We have a WiFi module always connected to i.MX6ULL processor over SDIO interface (4bit mode). My doubt is regarding SD1_CD_B pin. Is it necessary to have a pull down on this pin for SDIO to function? ( thought I could save a pin). In some designs (like Atmel) I could see DATA_3 pulled up for some purpose (DATA 3 also functions as card detect in that case).
i.MX6ULL says DATA_3 functions as a card detect in 1 bit mode.
Kindly clear clear the air.
Must I pull down SD1_CD_B or give pull ups on the data lines for a WiFi module to work over SDIO?
Will the SDIO interface work by tweaking software if SD1_CD_B is not used?