Req: USB pen SW interface

I want to use an USB pen to store data (no flash cards, too many pins) so I need an USB host device.

An USB host is normally associated with big controller (32bit) and separated USB controllers: too expensive!

Is possible to implement a subset of USB protocol by SW? Just to write data on the flash pen, not regarding the speed and the capability to connect multiple devices?

Best regards.

A.

:?: :?: :?:

I don't know about implementing USB host directly in a PIC. It could be possible, but I think you need at least a level converter. However Philips makes some USB chips with much USB logic inside. I looked at a USB device with serial interface (PDIUSBD11), no need for a large number of pins. Maybe you can find something similar for a USB host.

BR

Can't you just whip the memory chip out of the circuit?

It would be MUCH MUCH MUCH simpler?

if its a combined chip, your probably going to make it very painful and expensive, USB root is insainly difficult, just look at how far behind most linux distro's are in simple implimentations.