MSP430F5510: MSP430F5510 CDC example Descriptor Fail

Greg Girard

Part Number: MSP430F5510

I am trying to run the CDC example that is provided through the USB package and I am able to see it when I power it on and hold the PUR high but in the device manager it says descriptor failed. I did have to modify the XT2 frequency and auto detect constant because it was locking up the software. I am using the default descriptor that is in the USB_Config file. The software is running fine and sending the data every second but the host just throws the descriptor failed on connect

Any thoughts or places to start?

over 7 years ago

0 Jace H over 7 years ago

TI__Guru 56685 points

Hello Greg,

Are you trying to do an application side CDC example or trying to use the USB BSL? By pulling the PUR pin high on power on, you are initiating the USB BSL and not application side USB. The USB BSL is a HID interface, not CDC.

0 Greg Girard over 7 years ago in reply to Jace H

Prodigy 40 points

Hello Jace,

Reading more that makes sense. On the other hand, if I don't do anything to pull PUR to power, the PC never sees the USB device (nothing pops up in the device manager). I am trying to just do the CDC application so in the future I can use the USB port to debug what my code is doing. Any thoughts on why the CDC isn't coming up as a COM port when I plug it in with the PUR pulled up?

Thanks,
Greg

0 Arthi Bhat1 over 7 years ago in reply to Greg Girard

TI__Expert 6760 points

Hi Greg,
Are you using TI's EVM board or a board you created? Document, SLAA457a.pdf is a great source that explains how to start a USB design from scratch.

Can you also tell us the value of your XT2 crystal? Since you had to manually set it maybe this post will help with debugging why you had to manually set the XT2 value:

e2e.ti.com/.../2645773

Regards,
Arthi

0 Jace H over 7 years ago in reply to Arthi Bhat1

TI__Guru 56685 points

Greg,

In addition to Arthi's comments, as stated earlier when pulling PUR high during power up, this boots up the MSP430 in USB BSL mode which is a HID interface, not CDC.

0 Greg Girard over 7 years ago in reply to Jace H

Prodigy 40 points

This is a custom board with 12MHz oscillator. I changed the default code:

//USB_XT2Freq = USB_determineXT2Freq();
//USB_XT2PLL = USB_lookUpPll(USB_XT2Freq);

to:

USB_XT2Freq = 12; //12MHz
USB_XT2PLL = USBPLL_SETCLK_12_0; //12MHz

Noted on the HID issue but like I said, if i boot it up without the pullup, the PC doesn't see it. Thoughts why it can't see it?

0 Arthi Bhat1 over 7 years ago in reply to Greg Girard

TI__Expert 6760 points

Hi Greg,

Can you please verify that your custom board is to the design specified in Figure 8 of SLAA457A? The reason you might be seeing this issue is because your board is not designed correctly. You can also check out the USB schematics for TI's EVM board MSP-TS430RGC64USB target socket board.

Regards,

Arthi

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MSP430F5510: MSP430F5510 CDC example Descriptor Fail