CONTROL CIRCUIT FOR ASSOCIATIVE MEMORY AND THE ASSOCIATIVE MEMORY

摘要

PURPOSE: To reduce the dissipation power. ;CONSTITUTION: A timing control signal SR is set to a low level to turn on a P-MOSFET 62 and to turn ff an N-MOSFET 60, and the potential VMATCH₁ of NOT circuit 64 side of a matching line is pulled up to a power source voltage VDD at the N-MOSFET 60 as a boundary. Comparison is conducted by an associative memory cell 28 during this period. The N-MOSFET 42 is turned on or off in response to the comparison result. Then, the signal SR is set to high level to turn off the P-MOSFET 62 and to turn on the N-MOSFET 60. Thus, if the N-MOSFET 42 is turned on, the potentials VMATCH₁ and VMATCH are lowered to a ground level, but a through current is prevented by the off of the potential VMATCH. If the N-MOSFET 42 is off, VMATCH₁ is pulled up to VDD-V_th (V_th is the threshold value voltage of the N-MOSFET60), V is maintained at VDD by NOT circuit 64 and P-MOSFET 66, and the signal representing the comparison result is output from the NOT circuit 64.;COPYRIGHT: (C)1996,JPO