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Help calculator project using FPGA Spartan 3A

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Newbie level 5
Apr 18, 2011
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Hello Guys...
I want to make Calculator using FPGA Spartan 3A with VHDL code via keyboard.

I have connected PS2 Keyboard with Spartan's LCD.

My Problem is i don't have enough references how to make calculator logic.
any reference and script examples would help me alot...


The book by Pedroni is good, but is has one big problem.
It uses the non-standard libraries std_logic_unsigned and std_logic_arith.
It is very confusing for a beginner to see simple things like incrementing a counter done in different ways in different books/sources.

Go for the standard library numeric_std !
I recommend this book by Peter Ashenden: The Designer's Guide to VHDL, Volume 3, Third Edition (Systems on Silicon) (9780120887859): Peter J. Ashenden: Books

Ashenden's book is maybe not the best for hands-on experimenting, but it is much better as a reference than the Pedroni book.

For hands-on experience, go to a website like or similar.
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I started learning vhdl last month by myself.. I used pedroni's book. He did well in providing many examples but not that well in explanation. Yesterday I started Dougles Smith book "A practical Guid for designing, Synthesizing and simulation ASIC and FPGA's using vhdl and verilog" I heard positive feedback about it although it is an old book (1996).

Abeer :twisted:

would u like to give me some simple examples about my project :eek:

btw i use Xilinx ISE Design Suite 12.4 :D

sorry for this noob question :eek:

yes I do... I have connected connected PS2 Keyboard with LCD on xilink spartan 3a for my first project.

Now, I want to make a simple calculator using numpad on PS2 keyboard with LCD on xilink, but i don't know the mathematic logic for plus, minus, sub, div.

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