SN74AS877 Datasheet, PDF (1/10 Pages) Texas Instruments – 8-BIT UNIVERSAL TRANSCEIVER PORT CONTROLLERS

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SN54AS877, SN74AS877
8ĆBIT UNIVERSAL TRANSCEIVER PORT CONTROLLERS
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SDAS234 − D2661, DECEMBER 1982 − REVISED AUGUST 1985
• Package Options Include Plastic Small
Outline Packages, Both Plastic and
Ceramic Chip Carriers, and Standard
SN54AS877 . . . JT PACKAGE
SN74AS877 . . . DW OR NT PACKAGE
(TOP VIEW)
Plastic and Ceramic 300-mil DIPs
• Buffered 3-State Outputs Drive Bus Lines
Directly
• Cascaded to n-Bits
• Eight Selectable Transceiver/Port
S0 ₁
S1 ₂
S2 ₃
A1 ₄
A2 ₅
24 ^V_CC
23 ^CLK
22 ^SERIN
21 ^B1
20 ^B2
Functions:
A to B or B to A
Register to A or Register to B
Shifted to A or Shifted to B
Off-Line Shifts (A and B Ports in
High-Impedance State)
Register Clear
• Particularly Suitable for Use in Signature
A3 ₆
A4 7
A5 8
A6 9
A7 10
A8 11
GND 12
19 ^B3
18 B4
17 B5
16 B6
15 B7
14 B8
13 Q8
Analysis Circuitry
• Serial Register Provides:
SN54AS877 . . . JT PACKAGE
SN74AS877 . . . DW OR NT PACKAGE
Parallel Storage of Either A or B Input
(TOP VIEW)
Data
Serial Transmission of Data from Either
A or B Port
• Dependable Texas Instruments Quality and
Reliability
4 3 2 1 28 27 26
A1 5
25 B1
A2 6
24 B2
description
A3 7
NC 8
23 B3
22 NC
The ’AS877 features two 8-bit I/O ports (A1-A8
A4 9
21 B4
and B1-B8), an 8-bit parallel-load, serial-in,
A5 10
20 B5
parallel-out shift register, and control logic. With
A6 11
19 B6
these features, this device is capable of
12 13 14 15 16 17 18
performing eight selectable transceiver or port
functions, depending on the state of the three
select lines S0, S1, and S2. These functions
include: transferring data from port A to port B or
NC − No internal connection
vice versa (i.e., the transceiver function),
transferring data from the register to either port,
serial shifting data to either port, performing off-line shifts (with A and B ports in high-impedance state), and
clearing the register. Synchronous parallel loading of the internal register can be accomplished from either port
on the positive transition of the clock while serially shifting data in via the SERIN input. The ’AS877 is ideally
suited for applications needing signature-analysis circuitry to enhance system verification and/or fault analysis.
All serial data is shifted right. All outputs are buffer-type outputs designed specifically to drive bus lines directly
and all are 3-state except for Q8, which is a totem-pole output.
The SN54AS877 is characterized for operation over the full military temperature range of −55°C to 125°C. The
SN74AS877 is characterized for operation from 0°C to 70°C.
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.
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
Copyright  1985, Texas Instruments Incorporated
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