The PD4481161 is a 524,288-word by 16-bit, the PD4481181 is a 524,288-word by 18-bit, the PD4481321 is a 262,144-word by 32-bit and the PD4481361 is a 262,144-word by 36-bit ZEROSB static RAM fabricated with advanced CMOS technology using full CMOS six-transistor memory cell. The PD4481161, PD4481181, PD4481321 and PD4481361 are optimized to eliminate dead cycles for read to write, or write to read transitions. These ZEROSB static RAMs integrate unique synchronous peripheral circuitry, 2-bit burst counter and output buffer as well as SRAM core. All input registers are controlled by a positive edge of the single clock input (CLK).