Hello BP101, I split this topic out of our other customers thread since you want to continue discussion. I linked this post to that thread for any interested parties to continue following along. As you've identified, yes to follow USB standards we use 64 byte packets for FS mode. You can improve the throughput the way you describe but as it is no longer following USB standard you would have to do that in a close loop system that never actually interacts with a USB standard host. A USB2.0 compliant computer PHY would request device information on connection and the TM4C would reply back that it is a full speed device and thus the computer will limit speeds and use 64 byte packets unless the TM4C is configured for HS mode with an external PHY to drive the high speed communication. As far as the whole topic of USB2.0 with TM4C, our datasheet lists repeatedly that high speed operation or 2.0 operation requires an external PHY. "USB 2.0 Controller OTG/Host/Device with optional high speed using external PHY through ULPI interface" "USB 2.0 high-speed (480 Mbps) operation with the integrated ULPI interface communicating with an external PHY" On block diagram: "USB OTG (FS PHY or ULPI)" While we may agree to disagree on this subjective topic of clarity of statements, I would say we did our job to properly label the capabilities of the device and outlining what is and isn't met from a 2.0 high speed specification standpoint.
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