no data with WriteEP custom USB link

lpcware — Wed, 15 Jun 2016 20:23:30 GMT

Content originally posted in LPCWare by david35 on Fri Jun 19 07:11:17 MST 2015
Hi

I am working on a retro-design conception with a custom USB link based on a LPC1825. The host side is a PC with a Cypress driver (CyUSB3.sys, Cypress USB console). I need to configure a communication link using Endpoint2 in interrupt transfer.

All the EP0 transfers (SETUP_PACKET) seem to be good and the device is well enumerated by the host. Using USBVIEW.exe, I have the same device descriptor as the old product to be retro-designed.

At the beginning, I started with the VCOM example and I suppressed all the VCOM functions.

The problem is with the EP2_IN interrupt transfert. There is no data transfer from the device to the host. I use a USB analyzer to record data transfer.

The Endpoint2 is initialized with:

/* register endpoint interrupt handler */
ep_indx = ((EP2_IN & 0x0F) << 1) + 1;    // EP2_IN=0x82
ret = USBD_API->core->RegisterEpHandler(g_hUsb, ep_indx, EP2_hdlr, 0);

I Program transfer descriptors for given endpoint using bwtest_USB_Prog_DTD function from usbd_rom_bwtest example with:

usb_param.USB_Configure_Event = bwtest_ConfigureEvent;

The EP2 Handler is defined as:

ErrorCode_t EP2_hdlr(USBD_HANDLE_T hUsb, void *data, uint32_t event)
{
switch (event)
{
case USB_EVT_IN:
{
g_u32_CptItEP2IN++;
USBD_API->hw->WriteEP(g_hUsb, EP2_IN, (uint8_t*)g_tu8_TabEcp, 1024);
break;
}
default: break;
}

return LPC_OK;
}

With this code, when the host initiates a data transfer, an event USB_EVT_IN is well detected in the EP2_Hdlr function but no data is transferred to the host. This behavior is confirmed with the USB analyzer.

Something is missing. But what?
Thanks for your help.
David

LPC Microcontrollersのトピックno data with WriteEP custom USB link

no data with WriteEP custom USB link