I am pretty new to the Xilinx world and I am seeking the answers to my questions here. The requirements are listed here,
3.3V or 5V parts (compatible with TTL/HTCmos)
no smaller than XC95288
supported by free webpack
easy to deal with (PLCC or TQ or PQFP or PGA, no BGA)
more than 80 I/O pins
can buy in small quantities (3, for example).
low cost
XC95288/XC95288XL fit 1,2,3,4,5,6 but I think there might exist cheaper parts. Less than $10 will be considered good enough. Thanks.
BTW, is it easy to move a CPLD design (VHDL) to FPGA? It has mostly adders (5 MHz or lower) and state machines (20MHz). Thanks. If so, would you also let me know what FPGA family to look at, with those requirements applied?
I can tell you that item 1, 5 and 7 are hard to combine. The Xilinx parts that might do best are the Coolrunner (not Coolrunner II) XCR3128XL or larger. But they won't be cheap depending on how you define cheap. Expect to pay around $15 or so in 100's. If you need the XCR3256XL or larger the price goes up very quickly! I believe they want over $40 for the XCR3512XL. But prices are always negotialble.
Lattice has some parts as well, the 5000MX family. But be careful about the 5 volt tolerance, it has limitations.
Getting 5 volt tolerance in a PLD or FPGA is getting hard to find. If you don't need Flash non-volatility, look at the ACEX parts (EP1Kxx) from Altera. This is one of the more modern, low-cost, 5 volt tolerant FPGAs around.
--
Rick "rickman" Collins
rick.collins@XYarius.com
Ignore the reply address. To email me use the above address with the XY
removed.
Arius - A Signal Processing Solutions Company
Specializing in DSP and FPGA design URL http://www.arius.com
4 King Ave 301-682-7772 Voice
Frederick, MD 21701-3110 301-682-7666 FAX
If I remember right, I think the best combination of 5V tolerant and cheap is XC9500XL. Straight XC9500 has a price premium now, and XV is not 5V tolerant.
I don't have full pricing in front of me, but the newest CPLD part from Xilinx that has 5 volt tolerance is the XCR3xxxXL family, so I would expect these to be the cheapest. They are 3.3 volt supply and are near zero power as well. But like most CPLDs they get very pricey as the size goes up!
--
Rick "rickman" Collins
rick.collins@XYarius.com
Ignore the reply address. To email me use the above address with the XY
removed.
Arius - A Signal Processing Solutions Company
Specializing in DSP and FPGA design URL http://www.arius.com
4 King Ave 301-682-7772 Voice
Frederick, MD 21701-3110 301-682-7666 FAX
Xilinx 9500XL is the best choice for interfacing to 5V logic. Yet it's not capable of driving levels up to 5V, just 5V input tolerance. You can't get a single device for < 10$ in small or medium quantities.
9500XL has a maximum of logic ressources compared to coolrunner or even coolrunner2. Disadvantages of 9500xl: lot's of power consumption, drives only 8mA low,
4mA high.
Use a mix of 95144xl and 9572xl for cost optimisation.
If you need a quick and flexible solution for about 12-15$, use the smallest spartan3 device with an XCF01S platform flash and level shifters.
First, I should point out that Altera's mature MAX 7000 family is likely sufficient and widely available. The MAX 7000S is a 5.0V device with up to
256 macrocells. The MAX 7000AE is a 3.3V device with up to 512 macrocells. Both are available in a wide array of cheap, easy-to-use packages.
The new low-cost Max II family from Altera also meets many of your requirements. Max II is 3.3V compatible (both power rail voltage and I/O voltage). The EPM570 device offers 570 LEs, or roughly 440 macrocells. It is supported by the free Quartus II Web Edition software, available from our web site. There are three packages: a 100-pin TQFP (with 76 user I/Os), a
144-pin TQFP (with 116 user I/Os), and a 256-pin FBGA (with 160 user I/Os).
The downside is that you can't buy the EPM570 today -- only the EPM1270 is available. But it is shipping in a pin-compatible 144-pin TQFP, so you could prototype with it and plug in a EPM570 in early 2005 when it is available. I don't know the unit prices of any of our chips so I can't help you out there.
If we get the Web Edition software from
formatting link
you can try out all of our CPLD families to see how they do for density & performance. Your VHDL should work (provided it is generic) in any of our devices.
Max II's core fabric is more like an FPGA -- it uses LUT-based Logic Elements (LEs) instead of AND-OR macrocells. It also features a segmented, island-style routing architecture instead of the global fabrics found in older CPLD families. This family is perfect for you needs.
Generic VHDL should run push-button on Max II, or any other CPLD/FPGA product from pretty much any vendor. Just change the target device & push compile! And the speed targets you mention are slow by modern FPGA/CPLD standards, so they sound doable.
Ben Jackson wrote: : In article , rickman wrote: : >Ben Jackson wrote: : >> If I remember right, I think the best combination of 5V tolerant and : >> cheap is XC9500XL. Straight XC9500 has a price premium now, and XV is : >> not 5V tolerant. : >
: >I don't have full pricing in front of me, but the newest CPLD part from : >Xilinx that has 5 volt tolerance is the XCR3xxxXL family,
: I guess the original poster wanted "5V TTL compatible". The XC9500XL : family will take Vccio = 5V and drive 5V out. The XCR3xxxXL will accept : 5V in but Vccio = Vcc = 3.3V.
XC95XL takes only 3.3 Volt VCCIO, but is 5 Volt tolerant at the input
Yes, 5 volt TTL only requires the output to rise up to 2.4 volts.
--
Rick "rickman" Collins
rick.collins@XYarius.com
Ignore the reply address. To email me use the above address with the XY
removed.
Arius - A Signal Processing Solutions Company
Specializing in DSP and FPGA design URL http://www.arius.com
4 King Ave 301-682-7772 Voice
Frederick, MD 21701-3110 301-682-7666 FAX
I tried very recently the Quartus 4.1 Web Edition software with some VHDL sources originally targeted at Xilinx XC95288XL CPLD's. The software appears to me as more demanding in terms of thinking than the ISE Webpack, that, I think, takes you more "by the hand" if you do not want to bother too much about all possible synthesis and fitter options.
In general, the software "look" seems more attractive than the Xilinx (but this is of course strictly my personal opinion).
The VHDL designs I tried were immediately synthesized and fit into a EPM1270 chip (also tried the EPM570), with no adaptation (only standard VHDL used).
The LE/macrocell expected ratio (Altera says typical around 1.2) may be significantly exceeded, but the ratio is obviously dependent on the type of logic to fit (the MAXII are in fact "special" FPGA's, and comparison with CPLD is a bit shaky). I think designs with wide decoders will need a higher ratio, but I have also reached ratios as low as 1.1. with logics requiring plenty of registers and counters.
OK for that.
So,I really consider the possibility to move from Xilinx to Altera, at least as far as the CPLD's are concerned for now, especially considering the amount of LE's available in for instance the TQ144 package (I am sometimes short of resources with the already expensive XC95288XL or CoolRunner II top of the line CPLD).
I am however still a bit cautious about the "cheap" character of the MAXII CPLD's. I see a number of interrogations on the Web asking for "places to buy cheap MAXII devices".
For instance, EBV (a large European distributor) offers samples of the MAX1270T144C5 at around 26 euros. I have seen 24 dollars elsewhere in the world. But, on the other hand, EBV Belgian Branch message is that the prices per 100 could be as low as 12-14 euros (add 20% for dollars) and the prices of the future MAX570T144C5 as low as 8 euros. Does it sound reasonable ?
I am confused. I thought the OP was looking for 5 volt tolerant chips, no? I am pretty sure the MAX-II is not 5 volt tolerant. Or is it??? If it is, I would like to know more about the intro schedule. When is the LPM2210 planned?
"Paul Leventis (at home)" wrote:
--
Rick "rickman" Collins
rick.collins@XYarius.com
Ignore the reply address. To email me use the above address with the XY
removed.
Arius - A Signal Processing Solutions Company
Specializing in DSP and FPGA design URL http://www.arius.com
4 King Ave 301-682-7772 Voice
Frederick, MD 21701-3110 301-682-7666 FAX
A quick follow-up -- you can drive and listen to 5.0V-compatible signals with Max II. You can directly drive a 5.0V TTL device using all Max II devices since the Voh of the 3.3V output is above the 2.4V requirement of the TTL device.
To drive a 5.0V CMOS device, you need to enable the PCI clamping diode and use an external pull-up resistor. To listen to a 5.0V signal, you again enable the PCI clamp diode and add a series resistor to the connection. PCI clamping diodes are available on the two largest family members.
What if the 5 volt signal is bidir TTL? Doesn't the input resistor get in the way of driving the net?
--
Rick "rickman" Collins
rick.collins@XYarius.com
Ignore the reply address. To email me use the above address with the XY
removed.
Arius - A Signal Processing Solutions Company
Specializing in DSP and FPGA design URL http://www.arius.com
4 King Ave 301-682-7772 Voice
Frederick, MD 21701-3110 301-682-7666 FAX
ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.