Download Rio -2011- Hindi -

Hi all,

I'm using ST's CubeMX implementation on a F4 discovery board. I use ST's USB middlewares with FreeRTOS.

When I get a special OutputReport from PC side I have to answer nearly immediately (in 10-15 ms). Currently I cannot achieve this timing and it seems my high priority tasks can interrupt the USB callback. What do you think, is it possible? Because it's generated code I'm not sure but can I increase the priority of the USB interrupt (if there is any)?

Thank you, David

10 to 15 ms is very slow, so I'm sure its possible.

Where is the USB callback function called from? If it is an interrupt then it cannot be interrupted by high priority RTOS tasks. Any non interrupt code (whether you are using an RTOS or not) can only run if no interrupts are running.

Without knowing the control flow in your application its hard to know what to suggest. How is the OutputReport communicated to you? By an interrupt, a message from another task, or some other way?

The callback which receive the data from PC is called from the OTGFSIRQHandler (it's the part of the HALPCDIRQHandler function). I think the problem is SysTickHandler's priority is higher than OTGFSIRQHandler and it's cannot be modified, but the scheduler shouldn't interrupt the OTGFSIRQHandler with any task handled by the scheduler. Am I wrong that the scheduler can interrupt the OTGFS_IRQHandler?

Here's the full story:

Download Rio (2011) Hindi:

Blu, a domesticated Spix's macaw, lives with his owner, Linda, in Minnesota. He spends his days lounging around the house, playing with his toys, and getting pampered by Linda.

However, things don't go smoothly as Blu and Jewel have different personalities and disagree on how to proceed. Blu wants to return to his comfortable life with Linda, while Jewel wants to explore the Amazon rainforest and find more blue macaws.

Rio is a computer-animated musical comedy film produced by Blue Sky Studios and directed by Carlos Saldanha. The movie follows the story of Blu, a domesticated Spix's macaw who lives with his owner, Linda, in Minnesota.

One day, Tulio, a Brazilian ornithologist, arrives at their doorstep and informs them that Blu's father, Marcel, is alive and wants to meet him. Blu and Linda travel to Rio de Janeiro, where they meet Marcel, who reveals that Blu is actually a rare blue macaw.

Thank you for the answer, I think I'm a bit confused with the Cortex ISR priorities :-) What I can observe is if I use a much higher osDelay in my high priority task I can respond for the received USB message much faster. This is why I think tasks can mess up with my OTG interrupt.