SGS-THOMSON M54 Manuals

The M54/74HC690/691/692/693 are high-speed CMOS counters/registers fabricated in silicon gate C2MOS technology. They offer the high-speed performance of LSTTL combined with the low power consumption of CMOS. The internal circuit consists of three stages, including a buffer output, which provides high noise immunity and stable output. These devices integrate a synchronous counter, a four-bit D-type register, and quadruple two-line to one-line multiplexers with three-state outputs in a single 20-pin package. The counter can be programmed using the data inputs and features enable P and enable T inputs for easy expansion. The device can function as either a counter or a parallel register output.

The M54/74HC374 and M54/74HC534 are high-speed CMOS octal D-type flip-flops with 3-state outputs fabricated with silicon gate C2MOS technology. They have the same high-speed performance as LSTTL combined with true CMOS low power consumption. These 8-bit D-type flip-flops are controlled by a clock input (CK) and an output enable input (OE). On the positive transition of the clock, the Q outputs will be set to the logic state that were set up at the D inputs (HC374) or their complements (HC534). While the OE input is low, the eight outputs will be in a normal logic state (high or low logic level), and while high level, the outputs will be in a high impedance state. The output control does not affect the internal operation of the flip-flops. That is, the old data can be retained or the new data can be entered.