Dual 16-Bit Binary Counters with 3-State Output Registers

The SN74LV8154 device is a dual 16-bit binary counter with 3-state output registers, designed for 2-V to 5.5-V VCC operation.

The counters have dedicated clock inputs. The counters share a clocked storage register to sample and save the counter contents. Both counters share an asynchronous clear input. The 32-bit storage register can be mapped on the output bus 8-bits at a time. Four bus reads are needed to access the contents of both stored counts. The two counters can be chained by connecting CLKBEN to RCOA. All clocks are positive edge triggered. All other inputs are active low.

This device is fully specified for partial-power-down applications using Ioff. The Ioff circuitry disables the outputs, preventing damaging current backflow through the device when it is powered down.