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| Element | XC3000 | XC4000E | XC4000X | XC5200 | XC9000 | Spartan | SpartanXL | Spartan2 | Virtex |
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| NOR2, NOR2B1, NOR2B2, NOR3, NOR3B1, NOR3B2, NOR3B3, NOR4, NOR4B1, NOR4B2, NOR4B3, NOR4B4 | Primitive | Primitive | Primitive | Primitive | Primitive | Primitive | Primitive | Primitive | Primitive |
| NOR5, NOR5B1, NOR5B2, NOR5B3, NOR5B4, NOR5B5 | Primitive | Primitive | Primitive | Macro | Primitive | Primitive | Primitive | Primitive | Primitive |
| NOR6, NOR7, NOR8, NOR9 | Macro | Macro | Macro | Macro | Primitive | Macro | Macro | Macro | Macro |
Figure 7.35 NOR Gate RepresentationsThe NOR function is performed in the Configurable Logic Block (CLB) function generators for XC3000, XC4000, XC5200, Spartan, and SpartanXL. NOR gates of up to five inputs are available in any combination of inverting and non-inverting inputs. NOR gates of six to nine inputs are available with only non-inverting inputs. To invert some or all inputs, use external inverters. Since each input uses a CLB resource, replace gates with unused inputs with gates having the necessary number of inputs.
Refer to the “NOR12, 16” section for information on additional NOR functions for the XC5200, Spartan2, and Virtex.
Figure 7.36 NOR5 Implementation XC5200Figure 7.37 NOR8 Implementation XC3000Figure 7.38 NOR8 Implementation XC4000E, XC4000X, Spartan, SpartanXLFigure 7.39 NOR8 Implementation XC5200Figure 7.40 NOR8 Implementation Spartan2, Virtex