Embedded Computing Design August 2. Resource Guide by Open. Systems Media. Embedded Computing Design August 2. Resource Guide   Published on May 7, 2. Embedded Computing Design Magazine, 2. Resource Guide, Most Innovative Products of the Year, Transforming the Factory with the Internet of. Arachnid Labs. I was recently reminded about a very nifty little programmable logic chip that hasnt seen nearly enough attention from hobbyists and makers. Let me tell you about it. Background. Working on the Tsunami Kickstarter recently, a backer asked about including a frequency divider on the front end, to allow for higher speed and better accuracy frequency counting. Using a programmable divider in front of the timer. MHz signal gives you more accuracy than counting just one. Blackberry 9630 Os 6 here. My initial reaction was to say that it wasnt practical to add that functionality at this point in the design, but it set me thinking, and against my better judgement I started to look at the options. A programmable frequency divider seemed the obvious solution, but the only one that came up on a quick search was obsolete and likely in too large a package. Doing this with separate components would require two ICs a counter and a demux. Besides, this was all theoretical, right Its too late to make significant changes. Not so long ago, something like this would have been solved using something such as a PAL. Of course, those have since been obsoleted by CPLDs and FPGAs, but even the smallest and cheapest of those have a great many pins and would add significantly to the Bill of Materials cost for my project. Enter Greenpak. At that point I was reminded of a development kit I bought 6 months ago and hadnt used, for a neat little series of chips called greenpak. LjgQ8ho/S7IA61E3fkI/AAAAAAAAAjE/rG5ULIIWwtg/s1600/tb.JPG' alt='Vhdl Program For 8 Bit Up Down Counter Ic 74193' title='Vhdl Program For 8 Bit Up Down Counter Ic 74193' />Greenpaks are something like a modern take on PALs. Each one contains a collection of digital building blocks, such as lookup tables, flipflops, and counters, and a flexible routing matrix that allows you to connect them up as needed. Better yet, theyre cheap, starting at about 0. I was likely to need, coming preprogrammed with your design from the factory. I already had a discrete XOR gate on the board that I was using as part of the input signal chain I could eliminate that, and for only 8 cents extra, get a device I could program with a bunch of extra functionality too. The Greenpak. 3 development kit comes with a nice little test and programming board and a bunch of samples of the various chips in the range. The development board supports what they call emulation, but what its actually doing is writing your design to the chip in temporary memory so you can test it out. You can do this as many times as you want, but once you program it for real, thats it your chip will only ever function like that, no backsies. On the dev board, theres testpoints for each of the pins on the chip, and the IDE has a very nice interface to send digital and analog waveforms to the chip, as well as enabling the onboard LEDs, and configuring keyboard shortcuts to turn signals on and off. You can hook your scope up to the test points, or input signals on the expansion connector. Naturally, I whipped out the devkit and set to work trying to see if I could implement my required logic on one of their cheap as chips chips. Vhdl Program For 8 Bit Up Down Counter Ice' title='Vhdl Program For 8 Bit Up Down Counter Ice' />Their IDE uses a drag and drop style of programming, drawing wires between inputs and outputs in a manner that will be familiar to anyone whos used an EDA tool before. Individual components are configured by clicking them, where settings can be set, and truth tables entered. I wanted my new chip to do three things Replace the discrete XOR IC used in the phase detector. Add a frequency divider for the timer input on the AVR. Make it possible to use the square wave output from the DDS without outputting it on the aux connector. After an hour or sos work, I had this to show for myself In the top left the square wave signals from the input comparator and the DDS chip come in on pins 3 and 4, respectively. The component marked 2 bit LUT2 implements the original functionality of the XOR IC, outputting the resulting signal on Pin 1. Using this site ARM Forums and knowledge articles Most popular knowledge articles Frequently asked questions How do I navigate the site Job Interview Practice Test Why Do You Want This Job Answer this job interview question to determine if you are prepared for a successful job interview. In electronics, a flipflop or latch is a circuit that has two stable states and can be used to store state information. A flipflop is a bistable multivibrator. Thats goal 1 sorted Pin 2 acts as an output enable for the DDSs square wave output on pin 6, which is connected to the AUX connector. Theres goal 2. The rest of the circuit is concerned with implementing the frequency divider. In brief, the signal coming in on pin 3 is fed into a series of chained counters CNT0DLY0, 1, and 3, each one dividing it down further. A flipflop on the output of each takes the short pulse each counter outputs when it overflows and turns it into a proper 5. And the three components marked LUT0, LUT2, and LUT3 act as a 4 1 multiplexer, allowing two external pins to control which of the divided signals gets output to the microcontroller. Presto, goal 3 selectable frequency division by 1, 1. Vhdl Program For 8 Bit Up Down Counter IcinAnother hours work with the devkit, emulator, and my scope, and I was able to verify that everything behaved as expected. And half an hour in diptrace proved that removing the XOR and adding this new chip was quite straightforward. I still had time to rush the design revision off to Macrofab before they sent the release candidate 1 boards off for production. This also feels like significantly less design risk and cost than integrating two new chips to perform this function if that were the only option, the Tsunami would have remained as it was. Counter_Final.png' alt='Vhdl Program For 8 Bit Up Down Counter Icon' title='Vhdl Program For 8 Bit Up Down Counter Icon' />As it is, Im waiting for the first releease candidate boards so I can run a full set of tests in situ, but Im very optimistic. For the cost of 8 cents per Tsunami and a few hours of my time, I was able to add some truly useful new features. Maker friendly Its hard to see why these little chips arent more popular and well known, especially with hobbyists, than they are now. Join the new Arachnid Labs forums In response to numerous requests, weve set up a discussion forum where you can talk about Arachnid Labs products, as well as. E00 REVIEWMAKEUP COURSES. Students who lack the mathematics and systems background for graduate programs in engineering may be required to take the course in this. Qualcomms Falkor Targets Servers ARMv8Compatible CPU Boldly Discards 32Bit Compatibility. Stretching for the semiconductor industrys highesthanging fruit. Theyre really cheap, the devkit is affordable at only 6. Silego will produce a run of chips preprogrammed with your design on tape and reel at quantities starting at 1, for a very nominal price the 0. I keep quoting includes programming at quantities from 2. The IDE is available for Windows, Mac, and Linux. Their datasheets even fully document the bitstream the chips use for programming this chip is just dying for someone to write a VHDL or Verilog compiler for it. Theres just one thing these little chips really are just that little. The standard package is an 0. QFN. The part Im using has 1. For a sense of scale, heres me holding one. Yes, thats the pad of my thumb. These things really are tiny, and that really can be a bit of an impediment. Anyone with a soldering iron, some flux, and a bit of magnification can solder these though having hot air certainly makes life simpler but prototyping on a breadboard is going to be tough, and they certainly require a bit of patience to get right by hand on a PCB, unless youve got stencils and solderpaste. The obvious solution to this is breakout boards youll still need to solder them on, but from there you can plug them into a breadboard and use them like regular DIP chips. Or, to take it a step further, prepopulated breakouts, and an adapter for their excellent devkit to allow programming them in that form factor. Any takers Full disclosure I dont have any association with Silego or their parts other than being a happy customer. I just think their stuff is neat, and wanted to tell people about it.