SPI-to-USB bridge -- only 32 pins!!

kc5tja · Post by **kc5tja** » Fri Oct 19, 2007 2:19 am

http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3639

This chip looks REALLY juicy!!

And, it has 8 input and 8 output pins (dedicated directions), which makes this chip useful for things like motherboard control signals (e.g., enabling/disabling ROM-vs-RAM banks, controlling CPU clock speeds, etc).

So, for those who were looking to implement USB for their homebrew computers, this appears to be the chip we've been waiting for.

I should note: This chip also apparently works as a host controller too, so you can attach USB peripherals to it as you would a normal PC.

GARTHWILSON · Post by **GARTHWILSON** » Fri Oct 19, 2007 6:59 am

Thanks for the notice and link! The SPI fits right into our 65SIB.

OwenS · Post by **OwenS** » Fri Oct 19, 2007 6:49 pm

If you want a host controller, then theres also FTDI's Vinculum, and Cypress' offerings. Cypress' SL811HST looks especially interesting because of it's support for direct connection to an 8-bit data bus.

FTDI sell the Vinculum in single quantities direct to hobbyists. I don't know about obtaining Cypress' chips, but it seems places carry at least some of their products, as there is a moderately sized community arround their PSoC microcontrollers.

The Vinculum has the advantage that it's almost "Plug it in and go," but it's device support is what is built into the firmware. The SL811HST looks interesting because you write the drivers. On the other hand, you have to get much closer to the protocol.

In a way, I suppose it's like the difference between using a UART and bit banging serial. The UART can only do one thing: Be a UART. The bit banged sollution is more work for you and the processor.

At least it isn't bit banging USB!