MC74F259D Просмотр технического описания (PDF) - Motorola => Freescale
Номер в каталоге
Компоненты Описание
Список матч
MC74F259D Datasheet PDF : 5 Pages
| |||
8-BIT ADDRESSABLE LATCH
The MC54/74F259 is a high-speed 8-bit addressable latch designed for
general purpose storage applications in digital systems. It is a multifunctional
device capable of storing single line data in eight addressable latches, and
also a 1-of-8 decoder and demultiplexer with active HIGH outputs. The device
also incorporates an active LOW Common Clear for resetting all latches, as
well as an active LOW Enable.
• Serial-to-Parallel Conversion
• Eight Bits of Storage with Output of Each Bit Available
• Random (Addressable) Data Entry
• Active High Demultiplexing or Decoding Capability
• Easily Expandable
• Common Clear
FUNCTIONAL DESCRIPTION
The MC54/74F259 has four modes of operation as shown in the Mode Se-
lect Table. In the addressable latch mode, data on the Data line (D) is written
into the addressed latch. The addressed latch will follow the data input with
all non-addressed latches remaining in their previous states in the memory
mode. All the latches remain in their previous state and are unaffected by the
Data or Address inputs.
In the one-of-eight decoding or demultiplexing mode, the addressed output
will follow the state of the D input with all other outputs in the LOW state. In
the clear mode all outputs are LOW and unaffected by the address and data
inputs. When operating the MC54/74F259 as an addressable latch, changing
more than one bit of the address could impose a transient wrong address.
Therefore, this should only be done while in the memory mode. The Truth
Table below summarizes the operations of the MC54/74F259.
CONNECTION DIAGRAM
VCC MR E D Q7 Q6 Q5 Q4
16 15 14 13 12 11 10 9
1 2 3 4 56 78
A0 A1 A2 Q0 Q1 Q2 Q3 GND
MC54/74F259
8-BIT ADDRESSABLE LATCH
FAST™ SCHOTTKY TTL
16
1
J SUFFIX
CERAMIC
CASE 620-09
16
1
N SUFFIX
PLASTIC
CASE 648-08
16
1
D SUFFIX
SOIC
CASE 751B-03
ORDERING INFORMATION
MC54FXXXJ
MC74FXXXN
MC74FXXXD
Ceramic
Plastic
SOIC
LOGIC SYMBOL
14
15
13 D
E
MR
1 A0
2 A1
3 A2
Q0 Q1 Q2 Q3 Q4 Q5 Q6 Q7
4 5 6 7 9 10 11 12
FAST AND LS TTL DATA
4-133
Share Link: 