USB_DM_PDOWN AND USB_DP_PDOWN

JaimeR — Sat, 14 Feb 2009 01:08:09 GMT

I am using MCF52259 with USB interface, but I am also using 3 SPI interfaces.
My problem is I cant find any information about USB_DM_PDOWN AND USB_DP_PDOWN pins (in order to see if I can manage their function with other pins or not use them at all).
In the EV Board they use these pins for USB configuration but I need to use them for the Chip Select function.
What can I do?

Re: USB_DM_PDOWN AND USB_DP_PDOWN

mjbcswitzerland — Sat, 14 Feb 2009 04:47:07 GMT

Hi Jaime

The D+/D- pull downs are required in USB-OTG / HOST modes (the outputs are used to control pull-downs in the range 14.25k and 24.8k, which should be either active or high impedance depending on the mode).

If you are using only device mode you don't need them and it is probably best to remove the resistors to the CS outputs to ensure that there is no disturbance.

Generally these signals are static and so could probably be realized with normal ports.

However I don't have concrete experience with OTG mode so there may be an exception somewhere. Possibly some one else could confirm or explain consequences.

Regards

Mark

www.uTasker.com

ColdFire/68K Microcontrollers and ProcessorsのトピックUSB_DM_PDOWN AND USB_DP_PDOWN

USB_DM_PDOWN AND USB_DP_PDOWN

Re: USB_DM_PDOWN AND USB_DP_PDOWN