Is a CPLD right for this?

[Svcguy]

Hello all,

I've never really used Cplds before and am wondering if they're right for a project I'm working on. I have a PIC24f that I'll be using the EPMP module to interface with various flash eeproms. The eeproms are on the other side of a proprietary connector and are all 5v. I'm looking to kill two birds with one stone here and have the cpld do the 3.3 to 5 logic level translation and provide the ability to switch the pin configuration (the epmp pinout is fixed). The epmp module uses about 50 io and the connector to the flash memory uses about the same. Finally, I'm a hobbyist, so it needs to come in a package that's hand solderable. Is a cpld right for this or am I way off

Thanks,
Andy

 

[barry]

First of all, I'm not sure you will find a CPLD capable of 5V outputs. There are devices (Lattice ispMACH for one) that are 5V tolerant, but that simply means you can apply a 5V INPUT without harming the device. If you can tolerate the low-speed that would occur if you use open-drain outputs, then you might be able to use one of these devices.

Since you've got 50 ins and 50 outs (if I read that right), you are probably talking about a 144-pin QFP package. These are 'hand solderable, but you'll probably need a magnifying light at the very least (unless you've got really good eyes). And a good iron.

But otherwise a CPLD will certainly be able to do what you want. I assume you'll want some kind of input (switch or command from the uP) to tell the CPLD to switch its pin-mapping, right?

 

[nba83]

you can use XC9572 CPLDs which are 5 volt compliant and also there are 5v versions, they come in PLCC package