These questions have probabaly been asked several times but here goes. I have a software background and want to learn FGPA programming. A friend of mine says that Verilog is the language to learn. I am interested in a recommended book to learn verilog. Another friend of mine said that the Altera tools are much better than Xilinx. Also one of the sales people (Xilinx Rep) I talked with say that the Spartan 3E is a better value than the Cyclone II parts. I am looking for pointers in any of these areas from people who actually use these tools and parts. I dont want to solicit a religous war, but I do want to know some opinions.
Try not to think of it as programming. You are designing hardware. Hardware can be very parallel. Think having several memories and reading from all of them at the same time. Think of having several calculation units (like adders), and using them for different calculations at the same time. Hardware works well when pipelined. If A, B and C are fetched from memories, rather than trying to do A+B*C in one clock cycle it would probably make sense to fetch B and C on one clock cycle, multiply B*C and fetch A on the next, do the addition on the next, and save the result on the fourth clock. Notice that it takes four clocks to get the first answer, and the same hardware can repeat the calculation a clock cycle later. Software is (usually) doing exactly one thing at a time.
Over half of the FPGA designs are in VHDL. Both VHDL and Verilog are not ideal languages for hardware design, however VHDL both allows for higher levels of abstraction and better low level control than Verilog. Of course, the choice of languages is rarely based on the merits of the languages.
VHDL is harder to learn, and easier to master. Verilog is easier to learn, and harder to master. The area under the learning curve is about the same.
In terms of employment, right now Monster.com for the USA, "Verilog and FPGA" came up with 105 hits, and "VHDL and FPGA" came up with 148. It is the reverse in the ASIC world.
Of course, I don't know where you are. Some locations and some industries are heavy on Verilog, some are heavy on VHDL. You need to learn the local language, what ever that is. Your friend might have the correct answer for where you are.
Maybe yes, maybe no, this week. Xilinx and Altera are kind of like Coke and Pepsi, or VHDL and Verilog.
At times in the past decade, Altera was leading. Right now, I'd say that Xilinx has both better parts, and the better tools. Next week, that might change. For most designs, both parts will do fine. For most designs, both tool sets will do fine. If you learn how to design well with one family, it will be easy to learn to design with the other family.
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Phil Hays to reply solve: phil_hays at not(coldmail) dot com
If not cold then hot
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