TEXAS INSTRUMENTS SN74BCT2423A, SN74BCT2424A Technical data
16-BIT LATCHED MULTIPLEXER/DEMULTIPLEXER BUS TRANSCEIVERS
D
Multiplexed Real-Time and Latched Data
D
Byte Control for Byte-Write Applications
D
Useful in NuBust Interface Applications
D
Useful in Memory Interleave Applications
SN74BCT2423A, SN74BCT2424A
SDIS013 – JULY 1989 – REVISED AUGUST 1990
D
BiCMOS Design Substantially Reduces
Standby Current
D
Dependable Texas Instruments Quality and
Reliability
AENL
ABLEA
ABENL
GND
AB
AB
AB
AB
GND
AB
AB
AB
AB
V
CC
A/BSEL
BLE
BENL
SN74BCT2423A . . . FN PACKAGE
A0
A1
A2
A3
A4
8765493
10
11
12
13
7
14
6
15
5
16
4
17
18
3
19
2
20
1
21
0
22
23
24
25
26
27
28 29
31 32 33 34
30
A5
A6
(TOP VIEW)
A7
GND
A8
168672
35 36 37 38 39
A9
66 65
A10
A1 1
64 63 62 61
40 41 42 43
A12
A13
A14
A15
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
AENM
ALE
V
CC
V
CC
AB15
AB
14
13
AB
AB
12
GND
11
AB
AB
10
9
AB
AB
8
GND
ABENM
ABLEB
BENM
B2B3B4
B0
B1
NuBus 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.
B5B6B7
B8
GND
B9
B10
B1 1
B12
B13
B14
B15
Copyright 1990, Texas Instruments Incorporated
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
1
SN74BCT2423A, SN74BCT2424A
16-BIT LATCHED MULTIPLEXER/DEMULTIPLEXER BUS TRANSCEIVERS
SDIS013 – JULY 1989 – REVISED AUGUST 1990
AENL
ABLEA
ABENL
GND
AB7
AB6
AB5
AB4
GND
AB3
AB2
AB1
AB0
V
CC
A/BSEL
BLE
BENL
SN74BCT2424A . . . FN PACKAGE
A0
A1
A2
A3
8765493
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
28 29
27
30
31 32 33 34
A4
(TOP VIEW)
A5
A6
A7
35 36 37 38 39
GND
168672
A8
A9
A10
66 65
A1 1
A12
A13
64 63 62 61
40 41 42 43
A14
A15
60
59
58
57
56
55
54
53
52
51
50
49
48
47
46
45
44
AENM
ALE
V
CC
V
CC
AB15
AB14
AB13
AB12
GND
AB1 1
AB10
AB9
AB8
GND
ABENM
ABLEB
BENM
B8
B0
B1
B3B4B5
B2
B6
B7
GND
B9
B10
B1 1
B12
B13
B14
B15
description
The ’BCT2423A and ’BCT2424A are general-purpose 16-bit bidirectional transceivers with data storage latches
and byte control circuitry arranged for use in applications where two separate data paths must be multiplexed
onto, or demultiplexed from, a single data path. Typical applications include multiplexing and/or demultiplexing
of address and data information in microprocessor- or bus-interface applications. These devices are also useful
in memory-interleaving applications. The ’BCT2423A and ’BCT2424A offer inverted and noninverted data
paths, respectively.
The ’BCT2423A and ’BCT2424A were designed using Texas Instruments BiCMOS process, which features
bipolar drive characteristics, but also greatly reduces the standby power of the device when disabled. This is
valuable when the device is not performing an address or data transfer.
Three 16-bit I/O ports, A15–A0, B15–B0, and AB15–AB0 are available for address and/or data transfer. The
AENM
, AENL, BENM, BENL, ABENM, and ABENL inputs control the bus transceiver functions. These control
signals also allow byte-control of the most significant byte and least significant byte for each bus.
Address and/or data information can be stored using the internal storage latches. The ALE
ABLEB
inputs are active low, and are used to control data storage. When the latch enable input is low , the latch
is transparent. When the latch enable input goes high, the data present at the inputs is latched, and remains
latched until the latch enable input is returned low.
Data on the ’A ’ bus and ’B’ bus are multiplexed onto the ’AB’ bus via the A
is low, A15–A0 is mapped to the AB15 –AB0 outputs. When A
/BSEL is high, B15 –B0 is mapped to the
/BSEL control line. When A/BSEL
AB15–AB0 outputs.
, BLE, ABLEA, and
The SN74BCT2423A and SN74BCT2424A are characterized for operation from 0°C to 70°C.
2
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
SN74BCT2423A, SN74BCT2424A
16-BIT LATCHED MULTIPLEXER/DEMULTIPLEXER BUS TRANSCEIVERS
SDIS013 – JULY 1989 – REVISED AUGUST 1990
logic symbol for the ’BCT2423A
59
10
60
9
2
66
61
24
27
34
36
AENL
AENM
A
/BSEL
ALE
A0
A7
A8
A15
B0
B7
B8
†
ALE
AENL
AENM
0
7
8
15
ASEL
BSEL
0
7
8
LATCHED MUX/DMUX
’BCT2423A
AL
AM
BL
Φ
11
45
12
46
22
19
17
14
48
51
53
ABLEA
ABLEB
ABENL
ABENM
0
AB
AB
3
AB
4
AB7
AB
8
AB
11
AB
12
ABL
ABM
ABLEA
ABLEB
ABENL
ABENM
0
3
4
7
8
11
12
BM
B15
BLE
BENL
BENM
†
These logic symbols are in accordance with ANSI/IEEE Std 91-1984.
43
25
26
44
15
BLE
BENL
BENM
13
56
AB
15
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
3
SN74BCT2423A, SN74BCT2424A
16-BIT LATCHED MULTIPLEXER/DEMULTIPLEXER BUS TRANSCEIVERS
SDIS013 – JULY 1989 – REVISED AUGUST 1990
logic symbol for the ’BCT2424A
59
10
60
9
2
66
61
24
27
AENL
AENM
A
/BSEL
ALE
A0
A7
A8
A15
B0
†
ALE
AENL
AENM
0
7
8
15
ASEL
BSEL
0
LATCHED MUX/DMUX
’BCT2424A
AL
AM
Φ
11
45
12
46
22
19
17
14
48
ABLEA
ABLEB
ABENL
ABENM
AB0
AB3
AB4
AB7
AB8
ABL
ABLEA
ABLEB
ABENL
ABENM
0
3
4
7
8
BL
B7
B8
B15
BLE
BENL
BENM
†
These logic symbols are in accordance with ANSI/IEEE Std 91-1984.
34
36
43
25
26
44
7
8
BM
15
BLE
BENL
BENM
ABM
11
12
13
51
53
56
AB11
AB12
AB15
4
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265