I am designing a device which requires an SD card for logging data, and I am using Microchip USB2240 as USB to SD bridge. I have all the parts on board (Referenced by Microchip).
I am able to log data to SD card as well as read data on my computer, but I have just realized that I cannot format the SD card nor delete any files from it.
I have a thought that this might be the problem with SD card WP switch, as I am using Micro SD card which doesn't have WP switch and USB2240 Evaluation board comes with the MMC socket. MMC has a WP switch (but the connections are true).
What will happen inside MMC when I move the switch to the lock position?
On the other hand, USB2240 has a SD_WP switch, which in my case is floating. They have not provided any information on this pin in the datasheet; whether I have to pull it HIGH or LOW to remove Write Protect.
Could the problem be either the write protect switch or SD_WP pin?
All the documentation on USB2240 bridge can be found here : LINK