SN74ACT7813
64 × 18 CLOCKED FIRST-IN, FIRST-OUT MEMORY
SCAS199B – JANUARY 1991 – REVISED APRIL 1998
DL PACKAGE
(TOP VIEW)
Member of the Texas Instruments
Widebus Family
Free-Running Read and Write Clocks Can
Be Asynchronous or Coincident
RESET
D17
D16
D15
D14
D13
D12
D11
OE1
Q17
Q16
Q15
GND
Q14
1
56
55
54
53
52
51
50
49
48
47
46
45
44
43
2
Read and Write Operations Synchronized
to Independent System Clocks
3
4
Input-Ready Flag Synchronized to Write
Clock
5
6
V
7
Output-Ready Flag Synchronized to Read
Clock
CC
Q13
Q12
Q11
Q10
Q9
8
D10
9
64 Words by 18 Bits
V
10
11
12
13
14
CC
Low-Power Advanced CMOS Technology
D9
D8
Half-Full Flag and Programmable
Almost-Full/Almost-Empty Flag
GND
D7
GND
Q8
Bidirectional Configuration and Width
Expansion Without Additional Logic
D6 15
D5 16
D4 17
D3 18
42 Q7
41 Q6
40 Q5
Fast Access Times of 12 ns With a 50-pF
Load and All Data Outputs Switching
Simultaneously
39
38
37
36
35
34
33
32
31
30
29
V
CC
19
20
21
22
23
24
25
26
27
28
D2
D1
Q4
Data Rates up to 67 MHz
Q3
Pin-to-Pin Compatible With SN74ACT7803
and SN74ACT7805
D0
Q2
HF
GND
Q1
Packaged in Shrink Small-Outline 300-mil
Package Using 25-mil Center-to-Center
Spacing
PEN
AF/AE
WRTCLK
WRTEN2
WRTEN1
IR
Q0
RDCLK
RDEN
OE2
OR
description
The SN74ACT7813 is a 64-word × 18-bit FIFO
suited for buffering asynchronous datapaths up to
67-MHz clock rates and 12-ns access times. Two
devices can be configured for bidirectional data buffering without additional logic. Multiple distributed V
and
CC
GND pins, along with Texas Instruments patented output edge control (OEC ) circuit, dampen simultaneous
switching noise.
The write clock (WRTCLK) and read clock (RDCLK) are free running and can be asynchronous or coincident.
Data is written to memory on the rising edge of WRTCLK when WRTEN1 is high, WRTEN2 is low, and input
ready (IR) is high. Data is read from memory on the rising edge of RDCLK when RDEN, OE1, and OE2 are low
and output ready (OR) is high. The first word written to memory is clocked through to the output buffer regardless
of the RDEN, OE1, and OE2 levels. The OR flag indicates that valid data is present on the output buffer.
The FIFO can be reset asynchronously to WRTCLK and RDCLK. RESET must be asserted while at least four
WRTCLK and four RDCLK rising edges occur to clear the synchronizing registers. Resetting the FIFO initializes
the IR, OR, and half-full (HF) flags low and the almost-full/almost-empty (AF/AE) flag high. The FIFO must be
reset upon power up.
The SN74ACT7813 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
TexasInstruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Widebus and OEC are trademarks of Texas Instruments Incorporated.
Copyright 1998, 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.
1
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