✏️ HW 2

✏️ HW 2#

📜 Instructions#

Assignment is in gradescope

1. Scancode Decoder (VHDL)#

In this problem, you will build a VHDL entity called scancode_decoder which processes keyboard scancodes.

When you press a key on a keyboard, the keyboard sends an 8-bit code to the computer called a PS/2 scancode. Each key has its own scancode listed below. The relationship between the keys and their scancodes is not based on ASCII nor any other discernible pattern.

Build a component which converts an 8-bit scancode for the digits 0–9 into a 4-bit hexadecimal value.

Keyboard Scancode Table#

Keyboard Key	0	1	2	3	4	5	6	7	8	9
Scancode (hex)	0x45	0x16	0x1E	0x26	0x25	0x2E	0x36	0x3D	0x3E	0x46

Component Specification#

Nomenclature: scancode_decoder
Data Input:
scancode = std_logic_vector(7 downto 0);
Data Output:
decoded_value = std_logic_vector(3 downto 0);
Control: none
Status: none

Behavior#

Converts a scancode, representing a keypress of a decimal digit, into its 4-bit value.

Example:
If scancode = 25₁₆ (the scancode for the character “4”), then the converter should output: 0b0100

Assume that the inputs are always legal hexadecimal scancodes.

Use the when statement syntax to describe the output in terms of the input.

Deliverables#

a. HW2_CODE#

In gradescope, submit a zip file to the HW2_CODE assignment. The zip file should contain only your scancode_decoder.vhd and scancode_decoder_tb.vhd in the root of the zip file (no subfolders).

b. HW2#

In gradescope there is a second assignment called HW2. This is where you’ll submit the following:

Provide a cropped screenshot of the resulting simulation timing diagram
Ensure the signal values are legible
GitHub commit and tagged with the VHDL code for your Scancode Decoder component and the testbench
Tag your commit with the tag “HW2”