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I have to make a PS2 Keyboard Controller project at the university and i encountered a few problems when trying to test the system on the FPGA board.

It had worked perfectly in the simulator of Active-HDL, but i am not sure what it might be that stops it from working on the board, because when i try to program the board, the .bit file gets uploaded, but it does not react when i plug the PS/2 Keyboard in it and try to press a key.

I thought that probably a problem might be related to the PS/2 Keyboard protocol or the way it is synthesized for the board, but i really do not know.

The source code is here https://wetransfer.com/downloads/1d000a9feb241ff84693fca2084b0e9a20180513165005/8f7ca4 and the top level is called "ps2_top_src". I am sorry for the way of uploading the code, but i couldn`t make it upload anywhere else.

motiondev
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  • Welcome to StackOverflow. Please place the relevant code inside of your question, making a [mcve]. – JHBonarius May 13 '18 at 20:31
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    It is quite easy to have different simulation results then in-circuit results. That is because many constructs that are possible in VHDL are not properly synthesized. You need to follow the VHDL coding guidelines provided by you FPGA tool manufacturer. – JHBonarius May 13 '18 at 20:32
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    For example this `process(clk, busyReceive_n) begin busyReceive <= busyReceive_n; end process;` (Core.vhd) simulates as a latch gated by clk but won't synthesize that way and won't show up in the latch log. The sensitivity list is ignored, it's an assignment statement, a different name for a wire. You'd think this should have been an edge sensitive sequential element (a register, for a single bit a flip flop). There are other suspicious constructs such as latches implied where perhaps they shouldn't. Design HW, not SW noting the parentheses around conditions. See xst.pdf for coding techniques. –  May 13 '18 at 23:40

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