The M54/74HC590 is a high speed CMOS 8-BIT BINARY COUNTER REGISTER (3-STATE) fabri2 cated in silicon gate C MOS technology. It has the same high speed performance of LSTTL combined with true CMOS low power consumption. These devices each contain an 8-bit binary counter that feeds an 8-bit storage register. The storage register has parallel outputs. Separate clocks are provided for both the binary counter and storage register. The binary counter features a direct clear input CCLR and a count enable input CCKEN. For cascading, a ripple carry output RCO is provided. Expansion is easily accomplished by tying RCO of the first stage to CCKEN of the second stage, etc. Both the counter and register clocks are positiveedge triggered. If the user wishes to connect both clocks together, the counter state will always be one count ahead of the register. Internal circuitry prevents clocking from the clock enable. All inputs are equipped with protection circuits against static discharge and transient excess voltage. March 1993