Hello all,
I am newbie to the USB and understanding the USB SS in AM335x Soc. I Studied the TRM of AM335x and try to understand the USB (Host + Device )implementation in Starter ware 02.00.00.01. I am using the CCS Version 5.3 and evaluation board is EVM-SK. I have few doubts regarding USB SS and Starter ware USB Implementation.
1. The USB SS in TRM of AM335x describes in well format but it does n't describes the Core Specific Registers
and supported classes (like CDC-ACM and ECM) in detail.
Is there any document that describes the Core Specfic Registers?
2. In Starter ware Host Implementation during the pipes Allocation (in the open driver function) , The Pipes are allocated based on the unused. This seems fine but the device don't have the same end point Allocated.At the last means during host end point configuration, end point number of the device is writing to the Core specfic Register.Those Specific Description of the register is not defined in the TRM.
Is there any specific reason for using of this approach?
3.The CPPI 4.1 DMA used in the Host code, is DMA supports 30 Tx and Rx Channels?
How many channels will create in CPPI 4.1 DMA?
4.During the Driver initialization (open call) , for OUT Transitions DMA is enabled by setting the flags.Why DMA is not enabled for IN Transactions?
5.In HID class(Host Driver), The interrupt endpoint is polled based on the time interval (pipe scheduling) , after that the status of the PIPE is READING . How Host will know NAK came or not ?
The PIPE Should go to IDLE State after Receiving the NAK .Is there any implementation to identify the NAK?
Please guide me in proper direction.
Thanks in advance.
Regards
Rama Krishna