In that case what 'initialisation' codes are you talking about that are not mentioned in the datasheet?
Section 8.4.1 reads:
8.4.1. Initialization, for any one file operations a necessary step before
① CMD_SET_USB_MODE command, into the USB-HOST work mode or SD card host work mode (mode
② Waiting for connecting USB Flash Drive or SD card, USB Flash Drive can be checked by CH376
automatically and generate an interrupt notification, or by the MCU send CMD_DISK_CONNECT
command to CH376 for regularly check, SD cards must to be checked by MCU itself.
③ CMD_DISK_MOUNT command, initialize USB Flash Drive or SD card, and test the disk ready or not,
you can try again up to 5 times after failure
④The above steps need implementation only once, unless USB Flash Drive or SD card to reconnect after
disconnect, that must return to step ②
This is supposed to initialize a SD card or a flash drive. The datasheet does not mention how to initialize other devices, such as a keyboard, anywhere. I have seen people doing that, but I don't know how.