Simple Router

Prompt

Build a router circuit which forwards data from the input (din) to one of four outputs (dout0, dout1, dout2, dout3), specified by the address input (addr)

The address is a two bit value whose decimal representation determines which output value to use. Append to dout the decimal representation of addr to get the output signal name dout{address decimal value}. For example, if addr=b11 then the decimal representation of addr is 3, so the output signal name is dout3.

The input has an enable signal (din_en), which allows the input to be forwarded to an output when enabled. If an output is not currently being driven to, then it should be set to 0.

Input & Output Signals

• din: Input data.
• din_en: Enable signal for din. Forwards data from input to an output if 1, does not forward otherwise.
• addr: Two bit destination address. For example addr = b11 = 3 indicates din should be forwarded to output value 3 (dout3).
• dout0: Output 0. Corresponds to addr = b00.
• dout1: Output 1. Corresponds to addr = b01.
• dout2: Output 2. Corresponds to addr = b10.
• dout3: Output 3. Corresponds to addr = b11.

Example:

• Data width: 32
• Input 1
  • din = hbee
  • din_en: True
  • addr = h1
• Input 2
  • din = hbee
  • din_en: True
  • addr = h3
• Input 3
  • din = hbee
  • din_en: False
  • addr = h3