CPLD Devices

[Mark Durham]

Out of necessity I'm looking into the use of a CPLD in one of my designs as a 22V10 takes up too much space for what it offers. I've got hold of some PLCC44 Atmel ATF1502s and Xilinx XC9536s & XC9572s to play with.

Are there any other CPLD devices that I should consider?

My only real requirements are that:

1. The device should be "easily" programmable without any expensive programmer (bit bang JTAG via an FTDI serial chip?)

2. Work with 5V logic levels

3. Not surface mount

4. Use freely available (or low cost) design tools

As for capability, I'm looking to replace a few TTL logic chips and an LS139 and also handle the bus sizing logic for a 68020 or 68030.

I'd appreciate any guidance.

Mark.

[Ed Porter]

You could also consider Xilinx XC9500XL parts; they need a 3.3V supply but are 5V tolerant, and easier to find.

-ed

[Mark Durham]

Ed,

Thanks for that. I picked up an XC9572XL dev board from ebay that I thought might come in handy..

[Bill McMullen]

Along with the Xilinx XC2C and XC95 series, I've been mostly using the XCR3###XL series which I really like as they're extremely low power and 5V tolerant.  However since AMD cancelled all CPLDs, the XCR3's especially the PLCC variants, are typically becoming VERY expensive if you don't already have a supply of them.

What I really wanted to point out is that since you're using some Xilinx CPLDs, their programming code (i.e. IMPACT) can use a parallel cable that is easily built using 2 HC125 IC's and some discretes.  I've used a homebuilt version for many years and if you can't find the schematic, I can send you a copy.

[Mark Durham]

I probably should have mentioned that I have a cheap Xilinx JTAG SMT2 clone that I'm hoping - after having done a bit of research - might be the correct programmer for the XC95xx devices. 

[Bill Shen]

I use Altera EPM7xxxS CPLD, but they have also became expensive recently.  They are 5V part and programmer is inexpensive around $10.  The Quartus design software is free download.

Bill

[Mark Durham]

Bill,

I've noticed your extensive use of the Altera devices and they seem a good fit. A look at a MAX7000 datasheet indicates that if I stick with a PLCC package (I don't think my SMD skills are quite there yet) the the options are an EPM7032 (PLCC44), an EPM7064 (PLCC44, PLCC68 or PLCC84) or an EPM7096 (PLCC68 or PLCC84). The EPM7128 & EPM7160 are only available in PLCC84 which is pretty big for an RCBus "medium" board.

With my very limited exposure to CPLDs I wouldn't know how many gates / macrocells I would need. Perhaps the way forward is to implement my design in one of the tools and let it tell me the answer?

Mark.

[Bill Shen]

Since you are talking about replacing few gates, ‘139, and dynamic bus sizing logic, the smallest CPLD, EPM7032S and its equivalent, ATF1502 should be enough.  PLCC84 will fit 50x100mm board, but you don’t need EPM7128 for your design.

Bill

[Mark Durham]

Thank you for your insight Bill.