Been away in Adelaide but I have found an interesting book:
“Custom Raspberry Pi Interfaces - Design and build hardware interfaces for the Raspberry Pi” by Warren Gay ISBN-13 978-1-4842-2405-2 (paperback) ISBN-13 978-1-4842-2406-9 (electronic)
Chapter 2 is all about 5v-3v and 3v-5v interfacing, and he makes specific reference to the speed of the interfaces. He talks about the 74HCT family of chips for this purpose (specifically the 74HCT255, it is an 8 channel device and I think it is the big brother to the 74HCT125 4 channel device available from Core under SKU:ADA1787)
I am expecting the 74HCT125 to arrive on Monday next for me to trial…
