SN54ABT16646_08 Datasheet, PDF (1/17 Pages) Texas Instruments – 16-BIT BUS TRANSCEIVERS AND REGISTERS WITH 3-STATE OUTPUTS

SN54ABT16646, SN74ABT16646
16-BIT BUS TRANSCEIVERS AND REGISTERS
WITH 3-STATE OUTPUTS
SCBS212D – JUNE 1992 – REVISED JULY 1999
D Members of the Texas Instruments
Widebus™ Family
D State-of-the-Art EPIC-ΙΙB™ BiCMOS Design
Significantly Reduces Power Dissipation
D Latch-Up Performance Exceeds 500 mA Per
JESD 17
D Typical V_OLP (Output Ground Bounce) < 1 V
at V_CC = 5 V, T_A = 25°C
D Distributed V_CC and GND Pin Configuration
Minimizes High-Speed Switching Noise
D Flow-Through Architecture Optimizes PCB
Layout
D High-Drive Outputs (–32-mA I_OH, 64-mA I_OL)
D Package Options Include Plastic Shrink
Small-Outline (DL), Thin Shrink
Small-Outline (DGG) Packages and 380-mil
Fine-Pitch Ceramic Flat (WD) Package
Using 25-mil Center-to-Center Spacings
description
The ’ABT16646 devices consist of
bus-transceiver circuits, D-type flip-flops, and
control circuitry arranged for multiplexed
transmission of data directly from the input bus or
from the internal registers.
These devices can be used as two 8-bit
transceivers or one 16-bit transceiver. Data on the
A or B bus is clocked into the registers on the
low-to-high transition of the appropriate clock
(CLKAB or CLKBA) input. Figure 1 illustrates the
four fundamental bus-management functions that
can be performed with the ’ABT16646 devices.
SN54ABT16646 . . . WD PACKAGE
SN74ABT16646 . . . DGG OR DL PACKAGE
(TOP VIEW)
1DIR 1
1CLKAB 2
1SAB 3
GND 4
1A1 5
1A2 6
V_CC 7
1A3 8
1A4 9
1A5 10
GND 11
1A6 12
1A7 13
1A8 14
2A1 15
2A2 16
2A3 17
GND 18
2A4 19
2A5 20
2A6 21
V_CC 22
2A7 23
2A8 24
GND 25
2SAB 26
2CLKAB 27
2DIR 28
56 1OE
55 1CLKBA
54 1SBA
53 GND
52 1B1
51 1B2
50 V_CC
49 1B3
48 1B4
47 1B5
46 GND
45 1B6
44 1B7
43 1B8
42 2B1
41 2B2
40 2B3
39 GND
38 2B4
37 2B5
36 2B6
35 V_CC
34 2B7
33 2B8
32 GND
31 2SBA
30 2CLKBA
29 2OE
Output-enable (OE) and direction-control (DIR) inputs are provided to control the transceiver functions. In the
transceiver mode, data present at the high-impedance port may be stored in either register or in both. The
select-control (SAB and SBA) inputs can multiplex stored and real-time (transparent mode) 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. The direction control (DIR) determines which bus receives data when OE
is low. In the isolation mode (OE high), A data can be stored in one register and/or B data can be stored in the
other register.
When an output function is disabled, the input function is still enabled and can be used to store and transmit
data. Only one of the two buses, A or B, can be driven at a time.
To ensure the high-impedance state during power up or power down, OE should be tied to V_CC through a pullup
resistor; the minimum value of the resistor is determined by the current-sinking capability of the driver.
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.
Widebus and EPIC-ΙΙB are trademarks of Texas Instruments Incorporated.
PRODUCTION DATA information is 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.
Copyright © 1999, Texas Instruments Incorporated
On products compliant to MIL-PRF-38535, all parameters are tested
unless otherwise noted. On all other products, production
processing does not necessarily include testing of all parameters.
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