Posted on February 20, 2015 at 13:49I'm hoping this is my last Report Descriptor question. As I found out, the HS USB DMA in the '405 only has access to RAM memory locations. With this in mind, I copy the Report Descriptor to RAM from it's original location in FLASH. By setting a breakpoint, I can see that this operation is getting done correctly.
However, the complete Report Descriptor isn't getting transmitted correctly: anywhere from the last 5-45 bytes aren't correct according to my Protocol Analyzer. The first ~750 transmit without issue, but the last bytes are wrong. I have ensured that my temp RAM buffer is 4-byte aligned. The transfer works fine on the '427 when using FLASH as the memory location.
Any ideas?
#stm32-usb-dma
