# Hamming-weight demo
# fnh, 19.06.05
#

# trace  D0
# trace  D1
# trace  D2
# trace  D3
# trace  D4
# trace  D5
# trace  D6
# trace  D7
# trace  D8
# trace  D9
# trace  D10
# trace  D11
# trace  D12
# trace  D13
# trace  D14

# trace  S0
# trace  S1
# trace  S2
# trace  S3


process
  D0  <= 0
  D1  <= 0
  D2  <= 0
  D3  <= 0
  D4  <= 0
  D5  <= 0
  D6  <= 0
  D7  <= 0
  D8  <= 0
  D9  <= 0
  D10  <= 0
  D11  <= 0
  D12  <= 0
  D13  <= 0
  D14  <= 0
  wait 2 sec

  # now the fill in bits, bar-graph manner
  D0   <= 1
  wait 1 sec
  D1   <= 1
  wait 1 sec
  D2   <= 1
  wait 1 sec
  D3   <= 1
  wait 1 sec
  D4   <= 1
  wait 1 sec
  D5   <= 1
  wait 1 sec
  D6   <= 1
  wait 1 sec
  D7   <= 1
  wait 1 sec
  D8   <= 1
  wait 1 sec
  D9   <= 1
  wait 1 sec
  D10  <= 1
  wait 1 sec
  D11  <= 1
  wait 1 sec
  D12  <= 1
  wait 1 sec
  D13  <= 1
  wait 1 sec
  D14  <= 1
  wait 1 sec

  # and clear them, bar-graph again
  D0   <= 0
  wait 1 sec
  D1   <= 0
  wait 1 sec
  D2   <= 0
  wait 1 sec
  D3   <= 0
  wait 1 sec
  D4   <= 0
  wait 1 sec
  D5   <= 0
  wait 1 sec
  D6   <= 0
  wait 1 sec
  D7   <= 0
  wait 1 sec
  D8   <= 0
  wait 1 sec
  D9   <= 0
  wait 1 sec
  D10  <= 0
  wait 1 sec
  D11  <= 0
  wait 1 sec
  D12  <= 0
  wait 1 sec
  D13  <= 0
  wait 1 sec
  D14  <= 0
  wait 1 sec

  # single-bit now
  D0  <= 1
  wait 1 sec
  D0  <= 0
  D1  <= 1
  wait 1 sec
  D1  <= 0
  D2  <= 1
  wait 1 sec
  D2  <= 0
  D3  <= 1
  wait 1 sec
  D3  <= 0
  D4  <= 1
  wait 1 sec
  D4  <= 0
  D5  <= 1
  wait 1 sec
  D5  <= 0
  D6  <= 1
  wait 1 sec
  D6  <= 0
  D7  <= 1
  wait 1 sec
  D7  <= 0
  D8  <= 1
  wait 1 sec
  D8  <= 0
  D9  <= 1
  wait 1 sec
  D9  <= 0
  D10 <= 1
  wait 1 sec
  D10 <= 0
  D11  <= 1
  wait 1 sec
  D11  <= 0
  D12  <= 1
  wait 1 sec
  D12  <= 0
  D13  <= 1
  wait 1 sec
  D13  <= 0
  D14  <= 1
  wait 1 sec

  # two-bits now, top-to-bottom 
  D14  <= 1
  D13  <= 1
  wait 1 sec

  D14  <= 0
  D12  <= 1
  wait 1 sec

  D13  <= 0
  D11  <= 1
  wait 1 sec

  D12  <= 0
  D10  <= 1
  wait 1 sec

  D11  <= 0
  D9   <= 1
  wait 1 sec

  D10  <= 0
  D8   <= 1
  wait 1 sec

  D9   <= 0
  D7   <= 1
  wait 1 sec

  D8   <= 0
  D6   <= 1
  wait 1 sec

  D7   <= 0
  D5   <= 1
  wait 1 sec

  D6   <= 0
  D4   <= 1
  wait 1 sec

  D5   <= 0
  D3   <= 1
  wait 1 sec

  D4   <= 0
  D2   <= 1
  wait 1 sec

  D3   <= 0
  D1   <= 1
  wait 1 sec

  D2   <= 0
  D0   <= 1
  wait 1 sec

  # some two-bit combinations

  D1   <= 0
  D14  <= 1
  wait 1 sec

  D14  <= 0
  D9   <= 1
  wait 1 sec

  D0   <= 0
  D4   <= 1
  wait 1 sec

  D4   <= 0
  D9   <= 0
  wait 1 sec

  # now some fancy combinations
  D7  <= 1
  D8  <= 1
  D9  <= 1
  wait 1 sec

  D0  <= 1
  wait 1 sec
  
  D12 <= 1
  wait 1 sec
  

  pause
end