Philips 74HCT648
The 74HC/HCT648 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. The 74HC/HCT648 consist of bus transceiver circuits with 3-state inverting outputs, D-type flip-flops, and control circuitry arranged for multiplexed transmission of data directly from the internal registers.FEATURES
● Independent register for A and B buses● Multiplexed real-time and stored data
● Output capability: bus driver
● ICC category: MSI
GENERAL DESCRIPTION
7A. Data on the “A” or “B” QUICK REFERENCE DATA GND = 0 V; Tamb = 25 °C; tr = tf = 6 ns 74HC/HCT648 bus will be clocked into the registers as the appropriate clock (CPAB and CPBA) goes to a HIGH logic level. Output enable (OE) and direction (DIR) inputs are provided to control the transceiver function. In the transceiver mode, data present at the high-impedance port may be stored in either the “A” or “B” register, or in both. The select source inputs (SAB and SBA) can multiplex stored and real-time (transparent mode) data. The direction (DIR) input determines which bus will receive data when OE is active (LOW). In the isolation mode (OE = HIGH), “A” data may be stored in the “B” register and/or “B” data may be stored in the “A” register. When an output function is disabled, the input function is still enabled and may be used to store and transmit data.