SN74ALS2232A Datasheet, PDF (1/9 Pages) Texas Instruments – ASYNCHRONOUS FIRST-IN, FIRST-OUT MEMORY

SN74ALS2232A
64 × 8 ASYNCHRONOUS FIRST-IN, FIRST-OUT MEMORY
SCAS248 – FEBRUARY 1988 – REVISED MARCH 1990
D Independent Asynchronous Inputs and
Outputs
D 64 Words by 8 Bits
D Data Rates From 0 to 40 MHz
D Fall-Through Time . . . 20 ns Typical
D 3-State Outputs
description
This 512-bit memory uses advanced low-power
Schottky IMPACT-X™ technology and features
high speed and fast fall-through times. It is
organized as 64 words by 8 bits.
A FIFO memory is a storage device that allows
data to be written into and read from its array at
independent data rates. The function is used as a
buffer to couple two buses operating at different
clock rates. This FIFO is designed to process data
at rates from 0 to 40 MHz in a bit-parallel format,
word by word.
Data is written into memory on a low-to-high
transition of the load clock (LDCK) input and is
read out on a low-to-high transition of the unload
clock (UNCK) input. The memory is full when the
number of words clocked in exceeds by 64 the
number of words clocked out. When the memory
is full, LDCK signals have no effect on the data
residing in memory. When the the memory is
empty, UNCK signals have no effect.
NT PACKAGE
(TOP VIEW)
RST 1
D0 2
D1 3
D2 4
D3 5
V_CC 6
D4 7
D5 8
D6 ⁹
D7 ¹⁰
FULL ¹¹
LDCK ¹²
24 OE
23 Q0
22 Q1
21 Q2
20 Q3
19 GND
18 Q4
17 _Q5
16 _Q6
15 _Q7
14 _EMPTY
13 _UNCK
FN PACKAGE
(TOP VIEW)
D2
D3
V_CC
NC
D4
D5
D6
4 3 2 1 28 27 26
5
25
6
24
7
23
8
22
9
21
10
20
11
19
12 13 14 15 16 17 18
Q2
Q3
GND
NC
Q4
Q5
Q6
Status of the FIFO memory is monitored by the
FULL and EMPTY output flags. The FULL output
is low when the memory is full and high when the
memory is not full. The EMPTY output is low when
the memory is empty and high when it is not
empty.
NC – No internal connection
A low level on the reset (RST) input resets the internal stack control pointers and also sets EMPTY low and FULL
high. The outputs are not reset to any specific logic levels. The first low-to-high transition on LDCK, either after
a RST pulse or from an empty condition, causes EMPTY to go high and the data to appear on the Q outputs.
The first word does not have to be unloaded. Data outputs are noninverting with respect to the data inputs and
are at a high-impedance state when the output-enable (OE) input is low. The OE input does not effect either
the FULL or EMPTY output flags. Cascading is easily accomplished in the word-width direction, but is not
possible in the word-depth direction.
The SN74ALS2232A is characterized for operation from 0°C to 70°C.
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.
IMPACT-X 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.
Copyright © 1990, Texas Instruments Incorporated
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265
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