DEC_CC4, 8, 16

4-, 8-, 16-Bit Active Low Decoders

These decoders are used to build wide-decoder functions. They are implemented by cascading CY_MUX elements driven by lookup tables (LUTs). The C_IN pin can only be driven by a CY_INIT or by the output (O) of a previous decode stage. When one or more of the inputs (A) are Low, the output is Low. When all the inputs are High and the C_IN input is High, the output is High. You can decode patterns by adding inverters to inputs.

Figure 4.57 DEC_CC4 Implementation XC5200

Figure 4.58 DEC_CC4 Implementation Spartan2, Virtex

Figure 4.59 DEC_CC8 Implementation XC5200, Spartan2, Virtex