STM32H573 USB FS interface max 8 endpoints

[microcoder]

Greetings,

I am not quite a USB, or USBX, expert, but I do have a question.

I have a custom HW design utilizing the H573, and the USB FS port, which according to the datasheet

supports a max of 8 configurable endpoints.

We have a USB Hub chip integrated into the HW design, and hoped to support 4 USB devices behind

the hub. Assuming that each device is a 2.0 USB Flash Drive (Sandisk, or whatever vendor),

and each USB Flash drive consumes 3 endpoints (control, IN and OUT), this is twelve endpoints just for

the flash drives.

The number 8 (endpoints), is fixed in STM32H5 hardware?

 

Am I correct in saying that the four flash drive application will never work?

 

Thanks

Ken

[gbm]

A simple mass storage device (BOT-SCSI) uses only one pair of endpoints. H5 supports 8 pairs.

[FBL]

Hi ​@microcoder 

In host mode, the STM32 does not allocate device endpoints; it uses host channels or pipes to interface downstream devices. A typical USB mass storage flash drive uses EP0 + one bulk IN + one bulk OUT endpoint. The host uses one control pipe per connected device address. It’s not 4 independent hardware EP0s on the host controller.

I hope it’s clear