A 4-digit, pre-settable up/down decade counter with a pre-settable register which is continuously compared to the counter. The device has latched multiplexed segment and digit driver outputs for direct interfacing with common anode 7-segment LED displays. Leading zero suppression is incorporated but may be inhibited if not required, also the display outputs may be disabled allowing the display LEDs to be used for other purposes. Data is multiplexed into or out of the device via a tri-state BCD I/O port. Additional outputs are carry/borrow for cascading, zero output indicating when the count reaches 0000 and equal output appearing when the counter equals the preset value of the register. The count input is provided with a Schmitt trigger to prevent false triggering in noisy environments or with slowly changing inputs. Outputs are C-MOS / TTL compatible.
