SN74ACT2440 Datasheet, PDF (1/33 Pages) Texas Instruments – NuBusE INTERFACE CONTROLLER

SN74ACT2440
NuBus™ INTERFACE CONTROLLER
SCHS010 – D3158, OCTOBER 1988 – REVISED JANUARY 1991
• Designed for NuBus™ Interface
FN PACKAGE
Applications
(TOP VIEW)
• Supports Master, Slave, and Master/Slave
Applications
• Conforms to ANSI/IEEE Std 1196-1987
• Designed to Operate With SN74BCT2420
NuBus™ Data/Address Interface Devices
• Supports NuBus™ 1987 Block Transfers
With the Addition of the SN74ALS2442
• EPIC™ (Enhanced Performance Implanted
CMOS) 1-µm Process
• Fully TTL-Compatible
• Dependable Texas Instruments Quality and
Reliability
description
The SN74ACT2440 NuBus™ Controller handles
RESET
ARB0
GND
ARB1
GND
ARB2
GND
ARB3
GND
VCC
START
ACK
GND
RQST
GND
NMRQ
CLK
9 8 7 6 5 4 3 2 1 68 67 66 65 64 63 6261
10
60
11
59
12
58
13
57
14
56
15
55
16
54
17
53
18
52
19
51
20
50
21
49
22
48
23
47
24
46
25
45
26
44
27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
A1
A0
VCC
SIACK
SGNTA
LOCTM1
LOCTM0
NMREQ
GND
MHOLD
LACK
MLREQ
MRDY
NREQ
MDONE
NLOCK
NMSTR
NuBus™ signaling protocol in compliance with
ANSI/IEEE Std 1196-1987. The device allows a
simple connection to the NuBus™; typical
configurations include master-only, slave-only,
and master/slave. Additionally, it provides extra status and control lines to facilitate more sophisticated
approaches. With the addition of the SN74ALS2442, slave block transfers can be supported by this device. For
additional details on block transfers, consult the SN74ALS2442 data sheet and the application note titled
Supporting NuBus™ Block Slave Transfers Using Texas Instruments SN74ACT2440, SN74BCT2420, and
SN74ALS2442.
Figure 1 shows a typical NuBus™ interface using the ’ACT2440. Data and address buffering is handled via two
SN74BCT2420s. The SN74BCT2420s are BiCMOS buffers designed specifically for supporting NuBus™
interfacing. The ’ACT2440 provides the buffer control signals needed to directly drive the SN74BCT2420s;
however, in simpler applications, standard SSI and MSI buffers may be used in place of the ’BCT2420s.
The ’ACT2440 is comprised of five major signal groups: byte decode signals, data/address interface-control
signals, master/slave input signals, NuBus™ card-slot signals, and NuBus™ status signals. Byte decode
determines which type of NuBus™ cycle is being performed. Data/address interface control provides the
buffering signals required to multiplex and de-multiplex the NuBus™ data/address lines. The master/slave
inputs control the master- and slave-state machines. The NuBus™ card-slot signals interface with the NuBus™.
The NuBus™ status signals indicate the status of the master/slave-state machines and provide buffered
NuBus™ signals. Refer to Table 1 for additional details.
The SN74ACT2440 is characterized for operation from 0°C to 70°C.
NuBus is a trademark of Texas Instruments Incorporated.
EPIC is a trademark 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.
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Copyright © 1991, Texas Instruments Incorporated
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