USB MSC Transmit packet problem.

[oleksandr.karbivsky]

Hello. I have custom board with STM32H743 and USB3320 in Full Speed Mode. Dont have problem with initialization of MSC (Window read descriptor, configuration and other). But when read blocks from SD card some trouble occurs. With USBPcam and Wireshark I check than Windows read data from SD card in next sequnce: Sector 0 Size 512, Sector 0 Size 512, Sector 2 Size 512, Sector 0 Size 512, Sector 63 Size 512. When reading sector 63 problem occurs: data from STM32 transmitted but on PC dont received.

In debug I see that Sector 63 read success and USB_Transmit function also call.

Maybe someone have suggestions to resolve this problem?

[oleksandr.karbivsky · Accepted solution]

Hello. Problem resolved. Was bad PCB routing of ULPI lines between STM and USB3320. Line DIR was smaller that other lines. But it started working when pins speed changed from  HIGH_SPEED to VERY HIGH SPEED.