SN54HCT652 Datasheet, PDF (1/8 Pages) Texas Instruments – OCTAL BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS

SN54HCT652, SN74HCT652
OCTAL BUS TRANSCEIVERS AND REGISTERS
WITH 3-STATE OUTPUTS
SCLS179B – MARCH 1984 – REVISED MAY 1997
D Inputs Are TTL-Voltage Compatible
D Independent Registers and Enables for A
and B Buses
D Multiplexed Real-Time and Stored Data
D True Data Paths
D High-Current 3-State Outputs Can Drive up
to 15 LSTTL Loads
D Package Options Include Plastic
Small-Outline (DW) and Ceramic Flat (W)
Packages, Ceramic Chip Carriers (FK), and
Standard Plastic (NT) and Ceramic (JT)
300-mil DIPs
description
The ’HCT652 consist of bus-transceiver circuits,
D-type flip-flops, and control circuitry arranged for
multiplexed transmission of data directly from the
data bus or from the internal storage registers.
Output-enable (OEAB and OEBA) inputs are
provided to control the transceiver functions.
Select-control (SAB and SBA) inputs are provided
to select real-time or stored data transfer. A low
input level selects real-time data; a high input level
selects stored data. Figure 1 illustrates the four
fundamental bus-management functions that can
be performed with the ’HCT652.
Data on the A or B data bus, or both, can be stored
in the internal D-type flip-flops by low-to-high
transitions at the appropriate clock (CLKAB or
CLKBA) terminals regardless of the select- or
output-control terminals. When SAB and SBA are
in the real-time transfer mode, it is possible to
store data without using the internal D-type
flip-flops by simultaneously enabling OEAB and
OEBA. In this configuration, each output
reinforces its input. 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.
SN54HCT652 . . . JT OR W PACKAGE
SN74HCT652 . . . DW OR NT PACKAGE
(TOP VIEW)
CLKAB ₁
SAB ₂
OEAB ₃
A1 4
A2 5
A3 6
A4 7
A5 8
A6 9
A7 10
A8 11
GND 12
24 ^V_CC
23 ^CLKBA
22 ^SBA
21 OEBA
20 B1
19 B2
18 B3
17 B4
16 B5
15 B6
14 B7
13 B8
SN54HCT652 . . . FK PACKAGE
(TOP VIEW)
4 3 2 1 28 27 26
A1 ⁵
25 OEBA
A2 ⁶
24 B1
A3 7
23 B2
NC 8
22 NC
A4 9
21 B3
A5 10
20 B4
A6 11
19 B5
12 13 14 15 16 17 18
NC – No internal connection
The SN54HCT652 is characterized for operation over the full military temperature range of – 55°C to 125°C.
The SN74HCT652 is characterized for operation from –40°C to 85°C.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
UNLESS OTHERWISE NOTED this document contains PRODUCTION
DATA information current as of publication date. Products conform to
specifications per the terms of Texas Instruments standard warranty.
Production processing does not necessarily include testing of all
parameters.
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Copyright © 1997, Texas Instruments Incorporated
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