Now that I have a programming rig setup for some PLCC-44 CPLD's, I was thinking...how large can I go before I have to get into FPGA or pins so small I can't easily hand solder.

I think I could solder PLCC-84 with no problem. I have some PLCC-84 sockets at home and they're on .1" spacers. But, it's 84 pins...

I was looking at this CPLD:

http://www.mouser.com/Search/ProductDetail.aspx?qs=fH4tvdCgwtN3Qt072sj77g%3d%3d

Which is the ATF1508 at $12.47. It has 64 I/O's, 7.5ns and 128 macrocells. Plus, it's 5V tolerant.

So my question is, how large of a CPLD have you guys actually used in your projects? Was it overkill or did you wish you had more I/O? More speed? etc.

Thanks.

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Cat; the other white meat.

I have used the Xilinx XC95108 84 pin PLCC on SBC-3 and SBC-4. Both machines pretty much maxed out the capacity of these. Had I had more room and more pins, I would have been able to add more features. For instance, both had the 65SPI 44-pin CPLD in addition to the 84-pin CPLD.

I used sockets for these as I did not include JTAG on my boards and wanted them to be removable.

Daryl

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Please visit my website -> https://sbc.rictor.org/

The 53CF94 SCSI controller on POC's host adapter is a PLCC-84 package, which I mounted into a socket. I had no problem whatsoever soldering those 84 pins.


The ATF1504AS is the largest I've used so far, in POC V2. It has 32 I/O pins and 64 macrocells. The logic resources weren't a constraint, but I could have used more I/O pins. Next one in the POC series will use the 1508.

As for speed, I'm using the 10ns version of the 1504 and have determined that that is more than ample.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

So that was 69 pins? With no on-board JTAG? Wow. So the 1508 wouldn't handle all that. I believe it's 64 pins I/O.

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Cat; the other white meat.

Don't forget his units included video, which can eat up quite a bit of resources.

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x86?  We ain't got no x86.  We don't NEED no stinking x86!

After looking again, SBC-4 did have a JTAG port for the CPLD. I chose socket over direct solder and since I did not intend for users to reprogram the CPLD, I left the JTAG off to save board space on SBC-3. On SBC-4, I was able to make room for the JTAG port. I had a breakout board for the 84 pin PLCC that included a JTAG port so it was easy to pop out the CPLD, reprogram it, and replace it.

SBC-3 had video, which used up a lot of gates on counters. SBC-4 had a buffered expansion port and an interrupt controller (of sorts) which used up more pins than logic blocks.

Those devices all ran extremely warm, almost too hot to the touch. I used stick-on heat sinks in an attempt to keep them from over heating. On a plus side, I never had one fail.

Daryl

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Please visit my website -> https://sbc.rictor.org/

I am planning to use Lattice MachXO3 or XO2 for my next PCB (with 206 "pins"). They are all ballbonded with 0.8mm pitch, but I would say they are probably easier to solder than 0.4mm pins (which often ends with shorts)..

Soldering 0.5mm pins is actually quite easy if you just use enough flux and a flat beveled solder tip: https://www.youtube.com/watch?v=5uiroWBkdFY

I've also used an XC95108 in my micro. I/O was sufficient, and I expect unless you are looking to implement a full bus master, it would be enough pins for most 8 bit micros. I don't have the results from the build report, but I'm pretty sure these parts would be good to at least 20MHz.

I used it for Address decoding, Read/Write generation, Simple Interrupt controller, Tone generator, Bank switching, and an 8 bit latch for the high byte on the IDE port. There were about 10 pins left over after the core usage was allocated (I routed only the high byte of the address bus, plus A0). The 10 extra pins were used for the expansion connector, and eventually were used for more chip selects and interrupt inputs etc.

My eventually goal was to try implementing a simple DMA controller, and at that point I ran into the logic limitations of what I could do with a CPLD. Hence my next (current) board uses a pair of Altera Flex 10K FPGAs (specifically the EPF10K10). These are what I believe to be the most accessible FPGAs for incorporating in our 5V micros. They are available in PLCC84 and have at least 5 times the logic of something like the XC95108. Because they are runtime programmed via an external config flash, they are more work to integrate. It might seem a bit weird using an FPGA in a micro filled with retro-parts, but there.

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8 bit fun and games: https://www.aslak.net/

In my last 6502 project (ROMulus 2nd) I was using a ATF1508AS in a PLCC-84 on a PCB using a through-hole socket and a PCB. I like the ATF1508AS as it is still in production, generally available and it is a 5V device. With the PLCC-84 you have 64 user IO pins when using the JTAG (and you need that as it's the only cheap programming interface). However I plan to switch to the TQFP-100 package which first is smaller and gives you up to 80 user IO pins. I already soldered TQFP-100 (not a ATF1508AS) using a normal chisel tip and it works. But I recommend better equipment like a lamp with magnifying glass and bevel tips. Then it should be much easier.

Altera EPM7128SLC CPLD's for me and EPF10K10 FPGA's for TTL based stuff for me.. It's got about 68 pins usable and they're dirt-cheap on ebay ( $2 or thereabouts). They come in a variety of packages but I primarily use the 84 PLCC one. Make sure you get the 'S' part so you can use JTAG!

Yvo

I've been using the EPM7064 in TQFP-44 which gives 36 I/Os and 64 Macrocells which isn't bad. I'm more limited by the I/Os than the Macrocells for the Glue logic/IRQ stuff I want to do. I need more pins!

For video I was able to just fit an 80x30 Text mode vga controller in the 7064 but it doesn't seem to have enough macrocells to add things like scrolling etc so I'm looking at using the EPM7128S in PLCC-84 to achieve that.

I just moved over to the new LatticeXO3L-9400 which has 9400 LUTS and about 48KiB SRAM. How this compares to macrocells would be like comparing tomatoes to bananas, but they have a short note about it.



Well, I went from the 6800 to 9400 LUT version to get VGA, SDCard and some other stuff into it. More internal ram also helps to keep cost down. Lattice gave it to me for free, but I think they are going to charge around $15USD for it. The 1400 LUT version goes for $2USD now (!) and you can probably squeeze one of the 6502 cores into that as well. The smallest I have is a 256 LUT, and I made a special cut-down 65n02 for that.