| XC3000 | XC4000E | XC4000X | XC5200 | XC9000 | Spartan | SpartanXL | Virtex |
|---|---|---|---|---|---|---|---|
| Macro | Macro | Macro | Macro | Macro | Macro | Macro | N/A |
X74_139 implements one half of a standard 74139 dual 2- to 4-line decoder/demultiplexer. When the active-Low enable input (G) is Low, one of the four active-Low outputs (Y3 - Y0) is selected with the 2-bit binary address on the A and B address input lines. B is the High-order address bit. The non-selected outputs are High. Also, when G is High all outputs are High.
X74_139 can be used as a 4-output active-Low demultiplexer by tying the data input to G.
| Inputs | Outputs | |||||
|---|---|---|---|---|---|---|
| G | B | A | Y3 | Y2 | Y1 | Y0 |
| 0 | 0 | 0 | 1 | 1 | 1 | 0 |
| 0 | 0 | 1 | 1 | 1 | 0 | 1 |
| 0 | 1 | 0 | 1 | 0 | 1 | 1 |
| 0 | 1 | 1 | 0 | 1 | 1 | 1 |
| 1 | X | X | 1 | 1 | 1 | 1 |
Figure 11.5 X74_139 Implementation XC3000, XC4000, XC5200, XC9000, Spartans |  |
