Libraries GuideChapter 11: Design Elements (X74_42 to X74_521)
X74_157
Quadruple 2-to-1 Multiplexer with Common Select and Active-Low Enable
XC3000
| XC4000E
| XC4000X
| XC5200
| XC9000
| Spartan
| SpartanXL
| Spartan2
| Virtex
|
|---|
Macro
| Macro
| Macro
| Macro
| Macro
| Macro
| Macro
| N/A
| N/A
|
When the active-Low enable input (G) of the X74_157 multiplexer is Low, a 4-bit word is selected from one of two sources (A3 - A0 or B3 - B0) under the control of the select input (S) and is reflected on the four outputs (Y4 - Y1). When S is Low, the outputs reflect A3 - A0; when S is High, the outputs reflect B3 - B0. When G is High, the outputs are Low.
Inputs
| Outputs
|
|---|
G
| S
| B
| A
| Y
|
|---|
1
| X
| X
| X
| 0
|
0
| 1
| 1
| X
| 1
|
0
| 1
| 0
| X
| 0
|
0
| 0
| X
| 1
| 1
|
0
| 0
| X
| 0
| 0
|
Figure 11.13 X74_157 Implementation XC3000, XC4000E, XC4000X, XC5200, XC9000, Spartan, SpartanXL