Libraries GuideChapter 11: Design Elements (X74_42 to X74_521)
X74_521
8-Bit Identity Comparator with Active-Low Enable and Output
XC3000
| XC4000E
| XC4000X
| XC5200
| XC9000
| Spartan
| SpartanXL
| Spartan2
| Virtex
|
|---|
Macro
| Macro
| Macro
| Macro
| Macro
| Macro
| Macro
| N/A
| N/A
|
X74_521 is an 8-bit identity comparator with 16 data inputs for two 8-bit words (P7 - P0 and Q7 - Q0), active-Low data output (PEQ), and active-Low enable (G). When G is High, the PEQ output is High. When G is Low and the two input words are equal, PEQ is Low. X74_521 does a bit comparison of the two words to determine equality. When any of the two equivalent bits from the two words are not equal, PEQ is High.
Inputs
| Outputs
|
|---|
G
| P7, Q7
| P6, Q6
| P5, Q5
| P4, Q4
| P3, Q3
| P2, Q2
| P1, Q1
| P0, Q0
| PEQ
|
|---|
1
| X
| X
| X
| X
| X
| X
| X
| X
| 1
|
0
| P7 Q7
| X
| X
| X
| X
| X
| X
| X
| 1
|
0
| X
| P6Q6
| X
| X
| X
| X
| X
| X
| 1
|
0
| X
| X
| P5Q5
| X
| X
| X
| X
| X
| 1
|
0
| X
| X
| X
| P4Q4
| X
| X
| X
| X
| 1
|
0
| X
| X
| X
| X
| P3Q3
| X
| X
| X
| 1
|
0
| X
| X
| X
| X
| X
| P2Q2
| X
| X
| 1
|
0
| X
| X
| X
| X
| X
| X
| P1Q1
| X
| 1
|
0
| X
| X
| X
| X
| X
| X
| X
| P0Q0
| 1
|
0
| P7=Q7
| P6=Q6
| P5=Q5
| P4=Q4
| P3=Q3
| P2=Q2
| P1=Q1
| P0=Q0
| 0
|
Figure 11.45 X74_521 Implementation XC3000, XC4000E, XC4000X, XC5200, XC9000, Spartan, SpartanXL