CDC Bulk transfer is received in many events, USB HS.

embedded_eng_ — Tue, 10 Aug 2021 09:55:12 GMT

Hi,

I'm using lpcxpresso55s16_dev_composite_cdc_msc_bm example with a small modification in "kUSB_DeviceCdcEventRecvResponse" event which prints the received data.

case kUSB_DeviceCdcEventRecvResponse: { if ((1 == g_deviceComposite_hs->cdcVcomBulk.attach) && (1 == g_deviceComposite_hs->cdcVcomBulk.startTransactions)) { g_deviceComposite_hs->cdcVcomRecvSizeBulk = epCbParam->length; if (!g_deviceComposite_hs->cdcVcomRecvSizeBulk) { /* Schedule buffer for next receive event */ error = USB_DeviceCdcAcmRecv(handle, USB_CDC_VCOM_DIC_BULK_OUT_ENDPOINT, s_currRecvBuf_BULK, g_cdcVcomDicEndpoints_BULK[0].maxPacketSize); } usb_echo("%d NEW Bytes:\r\n", g_deviceComposite_hs->cdcVcomRecvSizeBulk); for(int i = 0 ; i < g_deviceComposite_hs->cdcVcomRecvSizeBulk ; i ++ ) { usb_echo("%X ", s_currRecvBuf_BULK[i]); if(i % 16 == 0 && i != 0) usb_echo("\r\n"); if(i % 8 == 0 && i != 0) usb_echo(" "); } usb_echo("\r\n"); error = USB_DeviceCdcAcmSend(g_deviceComposite_hs->cdcVcomBulk.cdcAcmHandle, USB_CDC_VCOM_DIC_BULK_IN_ENDPOINT, "", 0); g_deviceComposite_hs->cdcVcomRecvSizeBulk = 0; g_deviceComposite_hs->cdcVcomSendSizeBulk = 0; } } break;

I'm sending a 512B packet using a C code to the relevant CDC port.

When I send the data, The data which is been sent is:

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

The problem is that the data isn't received in one event, it is received in many events:

43 NEW Bytes: 65 E4 9F 40 A2 37 4F B6 D2 D0 AE 99 AC E2 A4 22 8F 99 B4 45 4A 2E A4 D1 99 22 23 E7 E0 D2 6 3D 72 92 CE AF 25 EA 7E 59 D7 56 1 2 NEW Bytes: D A 82 NEW Bytes: BE 4D 91 13 B0 4B 33 62 F1 84 62 30 56 A0 2E 2A FB 7 70 E7 9A C9 64 62 2 15 19 E5 A1 F7 85 53 8B 94 D7 E7 8E B8 7E 6 C 9A 53 90 77 60 FF 9F E8 65 87 BD AD 8A 2C 70 A5 12 F9 D5 44 48 7D 47 79 D0 83 63 96 F3 D0 67 F0 4F 49 63 4A 5E 6E 10 52 3F 1 NEW Bytes: 9 57 NEW Bytes: C5 CD 9E 2C C2 AA 55 9E 31 ED 6D E5 A9 2A 1F 4C 72 D2 C8 96 2 3A 8A 4A 14 9B 26 AF 99 78 FB 15 E3 52 5F 53 D1 C0 21 59 A2 0 C 6F 5B AE 15 F2 19 DC D3 81 E3 11 ED 68 90 2 NEW Bytes: D A 60 NEW Bytes: 18 A1 41 AD 60 B6 1F 5B 54 98 93 4 1E 0 8E E2 FC 37 9C E8 C2 99 76 A5 8B C2 F7 43 60 7A 39 17 B3 8B 20 31 2 C4 D 86 2B 5C AC 4A 1F 4E B3 7 7B 63 5F 81 AD A5 B3 EF 82 6 60 46 2 NEW Bytes: D A 173 NEW Bytes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ytes: D A 92 NEW Bytes: B 33 4C 9A E4 94 6 2 7E 79 F4 6C 2B E4 26 65 71 B4 B9 1D 8A AA DF 77 9A AE FD 5 5F 9D 6E 18 D9 A0 ED D1 68 80 1D FE BC 11 89 21 30 D9 AB E2 83 6A D4 59 12 43 13 8 2F 57 37 35 CF 47 B3 7D 54 A1 A9 6D A8 CE A9 C2 64 8E 4B C9 F E4 D6 F8 13 54 25 89 83 6F E7 CF B4 6F 87 BB

516B were received.

Somehow, 4B were added.

Each 2 Bytes event includes "D A", but the D was not sent, just the A's, this explains the additional 4B.

My questions are:

* Why one send event is received as many events in the MCU, how can I fix it?

* Why these 4B were added?

* Why "USB_DeviceCdcAcmSend" function is needed in kUSB_DeviceCdcEventRecvResponse event? without it, just the first event is received.

Thanks

Re: CDC Bulk transfer is received in many events, USB HS.

FelipeGarcia — Wed, 01 Sep 2021 22:36:35 GMT

Hi,

I tested this on my side and I was not able to replicate your behavior, I modified same example on my side to print data on serial terminal once each packet is sent. I tested the example sending a 4096 bytes (8 HS USB packets) file through TeraTerm.

Please check my results, maybe you can tested on your side as well.

FelipeGarcia_0-1630535713706.png

Best regards,

Felipe

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Re: CDC Bulk transfer is received in many events, USB HS.

embedded_eng_ — Thu, 02 Sep 2021 06:55:35 GMT

Hi, the issue was caused by Linux driver, not from MCU's code.

I fixed it with setvbuf function.

Thanks!

topic CDC Bulk transfer is received in many events, USB HS. in LPC Microcontrollers

CDC Bulk transfer is received in many events, USB HS.

Re: CDC Bulk transfer is received in many events, USB HS.

Re: CDC Bulk transfer is received in many events, USB HS.