STM32F4xx USB Isochronous OUT Multitransactions are possible?

[morpeh89]

Posted on January 29, 2015 at 08:35

Hi!

I'm trying to implement USB High Speed Host on STM32F405 micro. I use IAR and corresponding examples for USB Host. Playing with examples, I had success in sending Bulk, Interrupt and single Isochronous packets.Now I'd like to send Isochronous OUT Multitransactions, that is when up to 3 packets are sended during 1 microframe. I know that in this case DATA0, DATA1, DATA2 and MDATA pids are used. But searching through the all example code I can not find any mentioning of MDATA, that seems strange. Maybe, it is not supposed to use that type of transfers...So, my questions are:1. Is it possible to implement ISO Multitransactions in STM32F4xx ? I hope to transfer three packets of 1024 bytes each - is it real?2. Are there any working examples of code for this case?Thanks in advance!

[AA22]

Yes, it is possible to use multitransactions and send three 1024-byte packets in one microframe. Although I don't have an example for the STM32F4, there are examples available for the STM32U5. You can refer to the following link for more details:

"https://github.com/STMicroelectronics/STM32CubeU5/tree/main/Projects/STM32U575I-EV/Applications/USBX"

I hope this helps! Let me know if you have any further questions.