219 PS2 keyboard Interface
219 : PS2 keyboard Interface
- Author: Tanish Khanchandani
- Description: PS2 keyboard interface to enter charecters into a computer. Use the PS2 hex scan codes (https://techdocs.altium.com/display/FPGA/PS2+Keyboard+Scan+Codes) to enter hex codes and it will send the letter to your computer.
- GitHub repository
- Clock: 6000 Hz
How it works
Most likely does not work. Takes in keyboard hex scan codes and sends data to your PC. The chip emulates a key being pressed down and released. (link to protocol - https://techdocs.altium.com/display/FPGA/PS2_W+-+Transmission+Protocols). The logic puts data into a parallel to serial interface and sends the data with some of the other protocol necessities to simulate a key being pressed and released.
How to test
Select clock with input 1. Set the first hex character using inputs 2-5. Set input 6 to 1. Set input 6 back to 0. Set the second hex character using inputs 2-5 and set input 7 to 1 and then back to 0. Set input 8 to 1 to send the data.
External hardware
3.3V to 5V logic level converter
IO
| # | Input | Output |
|---|---|---|
| 0 | clock | NC |
| 1 | hex Bit 1 | NC |
| 2 | hex Bit 2 | NC |
| 3 | hex Bit 3 | NC |
| 4 | hex Bit 4 | NC |
| 5 | Set 1st hex | NC |
| 6 | set 2nd hex | Clock |
| 7 | Enable to send | Data |