ps2 mouse initialization fails

Jul 11, 2008 4 Replies

Hi, I tried out 2 mouse modules. Both get stuck in the mouse initialization process. The mouse does not respond. The modules i tried out are :



  1. formatting link
    (gets stuck in state "send")
  2. from the book "FPGA prototyping by VHDL examples" (gets stuck in state "start")

Does anyone have any suggestions ? btw. the keyboard works fine. I have the digilent spartan 3 starter kit.



Best Regards Thorsten



Hi Thorsten!

In that case the mouse didn't initialize the own clock signal. What is the clock frequency you use? Did you adapt the constants in the VHDL file such that you drive the clock signal to zero for 100 us (or maybe longer)? You have to change the lines 135 and 144 according to your clock frequency.

Matthias

Hi Mathias, my clock frequency is 50MHz, the same as yours, I guess ;)

Best Regads Thorsten

Hi!

Well, almost. I used 49.152 MHz. Probably your mouse wants more init code? You could try another mouse and check.

Matthias

Hi, I bought a new mouse, and now it works fine ;) I got the info, that the voltage level of the FPGA output pin is 3.3V and the PS2 standard wants 5V. Maybe that is the problem ?!? Thanks for your help.

Best Regards Thorsten

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