P002 - PAL16L8A - byte enable decoder

   DS*  1     20  Vcc
  R/W*  2     19  nc
  SIZ1  3     18  nc
  SIZ0  4     17  nc
    A1  5     16  WE3*
    A0  6     15  WE2*
    nc  7     14  WE1*
    nc  8     13  WE0*
    nc  9     12  OE*
  GND  10     11  nc


# Note WE0 is MSB (D31..24)
#      WE3 is LSB (D7..0)

rd = R/W*
wr = ! rd

OE = DS & rd

WE3 = DS & wr & ((A1 = 1 & A0 = 1) |
                 (SIZ1 = 1 & A1 = 1 & A0 = 0) |
                 (SIZ0 = 0 & A1 = 1 & A0 = 0) |
                 (SIZ1 = 1 & SIZ0 = 1 & A1 = 0 & A0 = 1) |
                 (SIZ1 = 0 & SIZ0 = 0 & A1 = 0))

WE2 = DS & wr & ((A1 = 1 & A0 = 0) |
                 (SIZ1 = 1 & A1 = 0 & A0 = 1) |
                 (SIZ0 = 0 & A1 = 0 & A0 = 1) |
                 (SIZ1 = 1 & SIZ0 = 1 & A1 = 0 & A0 = 0) |
                 (SIZ1 = 0 & SIZ0 = 0 & A1 = 0 & A0 = 0))

WE1 = DS & wr & ((A1 = 0 & A0 = 1) |
                 (SIZ1 = 1 & A1 = 0 & A0 = 0) |
                 (SIZ0 = 0 & A1 = 0 & A0 = 0))

WE0 = DS & wr & (A1 = 0 & A0 = 0)