topic USB Low-Speed Mode in LPC11U14 in LPC Microcontrollers

USB Low-Speed Mode in LPC11U14

lpcware — Wed, 15 Jun 2016 19:36:48 GMT

Content originally posted in LPCWare by thangle0110 on Thu Nov 21 00:26:29 MST 2013
Hi all,
I want to know exactly that does the LPC11U14 support for low-speed mode?
Now, I have moved the 1.5K pullup from usb_d+ to usb_d-. When i connect it to the host, the host receive the low-speed usb, but it doesn't run correctly.(often suppended).

There're some information that, the LPC11U14 does not support for low-speed mode(full-speed only). But as i've seen in manual that it can work in low-speed.
So, anyone can give the correct information?
Thanks all.

Re: USB Low-Speed Mode in LPC11U14

lpcware — Wed, 15 Jun 2016 19:36:49 GMT

Content originally posted in LPCWare by phucvo on Thu Nov 21 20:58:32 MST 2013
I have same problem.
And i wonder that does the LPC11u14 support for USB 1.1.
Does anyone have ideal ?
Thanks all.

Re: USB Low-Speed Mode in LPC11U14

lpcware — Wed, 15 Jun 2016 19:36:49 GMT

Content originally posted in LPCWare by durgesh on Mon Nov 25 16:42:50 MST 2013
To use LPC11U in low-speed you need to some hardware/board and software changes.

Hardware changes:
[list]
[*] connect USB_DP to D- pin on connector. Leave the pull-up circuit on USB_DP line.
[*] connect USB_DM to D+ pin on connector.
[/list]

Software changes:
[list]
[*] Set USBCLKDIV to 8. Assuming you have configured USBPLL to generate 48MHz. For low-speed operation you need to supply 6MHz clock to USB block.
[*] Update USB descriptors appropriately per USB 1.1 specification.
[/list]

FYI, TID10880059 is used for certifying LS operation on LPC11U24 which is very similar to LPC11u14.