54ACT16652, 74ACT16652
16-BIT TRANSCEIVERS AND REGISTERS
WITH 3-STATE OUTPUTS

SCAS128C - MARCH 1990 - REVISED APRIL 1996

Copyright © 1996, Texas Instruments Incorporated

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of TexasInstruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

features

• Members of the Texas Instruments Widebus^TM Family
• Inputs Are TTL-Voltage Compatible
• Independent Registers and Enables for A and B Buses
• Multiplexed Real-Time and Stored Data
• Flow-Through Architecture Optimizes PCB Layout
• Distributed V_CC and GND Pin Configuration Minimizes High-Speed Switching Noise
• EPIC^TM (Enhanced-Performance Implanted CMOS) 1-m Process
• 500-mA Typical Latch-Up Immunity at 125°C
• Package Options Include Plastic 300-mil Shrink Small-Outline (DL) Packages Using 25-mil Center-to-Center Pin Spacings and 380-mil Fine-Pitch Ceramic Flat (WD) Packages Using 25-mil Center-to-Center Spacings

EPIC and Widebus are trademarks of Texas Instruments Incorporated.

description

The 'ACT16652 are 16-bit bus transceivers consisting of D-type flip-flops and control circuitry arranged for multiplexed transmission of data directly from the data bus or from the internal storage registers. The devices can be used as two 8-bit transceivers or one 16-bit transceiver.

Complementary output-enable (OEAB and ) inputs are provided to control the transceiver functions. Select-control (SAB and SBA) inputs are provided to select whether real-time or stored data is transferred. A low input level selects real-time data, and a high input level selects stored data. The circuitry used for select control eliminates the typical decoding glitch that occurs in a multiplexer during the transition between stored and real-time data. Figure 1 illustrates the four fundamental bus-management functions that can be performed with the 'ACT16652.

Data on the A or B bus, or both, can be stored in the internal D flip-flops by low-to-high transitions at the appropriate clock (CLKAB or CLKBA) inputs, regardless of the levels on the select-control or output-enable inputs. When SAB and SBA are in the real-time transfer mode, it is also possible to store data without using the internal D-type flip-flops by simultaneously enabling OEAB and. In this configuration, each output reinforces its input. Thus, when all other data sources to the two sets of bus lines are at high impedance, each set of bus lines remains at its last state.

The 74ACT16652 is packaged in TI's shrink small-outline package, which provides twice the I/O pin count and functionality of standard small-outline packages in the same printed-circuit-board area.

The 54ACT16652 is characterized for operation over the full military temperature range of -55°C to 125°C. The 74ACT16652 is characterized for operation from -40°C to 85°C.