5v to 3.3V bus translation and vice versa

Thread Starter


Joined Aug 31, 2011
Basic idea is to connect mc68000 to cyclone II, 5V device to 3.3V.

There is something wrong with quickswich devices. As I know MC68000 cant
support 3.3V (some versions can but mine just cant). When i use quickswich
any type i only get 5V to 3.3V translation and no vice versa. I need to use
dual voltage level translator with auto sensing. Even sn74lvc8t245 have direction control and txs0108e have auto sensing.
For last two days I m reading about Pericom articles and those articles are
just like IDT have for quickswich part. Devices are working from higher to
lower and I m thinking that I just cant use those devices. For some devices
who work with 5V can drive lower voltage levels that is ok but on my
situation is not. For example PI5CX and PI3CX series are only related to 5V
to 3.3V translation no bidirectional and then i need to use bus enable
input like on most devices. From A to B bus or from B to A bus, that is not
practical. Also some Pericom devices PI74LVC4245 who have two voltage on
each bus side but no auto sensing again I need to set direction sides. I
just dont know, as much i m reading only thing is txs0108e that I m using
on design right now. Also using Pericom or IDT devices we can use pull up
resistor connected to higher power source. I just dont know....