Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

MAX3000 CPLD bi-directional I/O with 5V pull-up

Hi How would I create a bi-directional pin with open-collector output on a MAX3000 CPLD? I have started the design with an open collector driver driving the pin and a 541 type buffer fo...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
16 years ago

Hi

Here is the entire schematic in a Word doc. You can zoom in to get a better view.

The (16) MOTORx_ENABLE_DIAG_A and MOTORx_ENABLE_DIAG_B pins need to be bi-directional. These are the pins that I am concerned about.

All outputs are open collector (I see I need to add some more open collector buffers)

note that I don't drive the CPLD with any type of clock.

This is simple logic replacement and a lot of level shifting.

The one CPLD replaces about 15-20 individual devices.

The design just fits a epm3064A with 66 IO

Thanks

Andre