SN74ACT7814-20DL集成电路（IC）的FIFO存储器规格书PDF中文资料

SN74ACT7814-20DL属于集成电路（IC）的FIFO存储器。由美国德州仪器公司制造生产的SN74ACT7814-20DLFIFO 存储器先入先出 (FIFO) 存储器可用于数字信息的短期存储，其中信息检索顺序和序列与信息存储顺序和序列相同。这类产品又称为队列或缓冲存储器，通常用于在单独的设备之间交换信息，尤其是在数据以不同的速率或在略微不同的时间点生成和使用的情况下。

Member of the Texas Instruments

WidebusE Family

Load Clock and Unload Clock Can Be

Asynchronous or Coincident

64 Words by 18 Bits

Low-Power Advanced CMOS Technology

Full, Empty, and Half-Full Flags

Programmable Almost-Full/Almost-Empty

Flag

Fast Access Times of 15 ns With a 50-pF

Load and All Data Outputs Switching

Simultaneously

Data Rates up to 50 MHz

3-State Outputs

Pin-to-Pin Compatible With SN74ACT7804

and SN74ACT7806

Packaged in Shrink Small-Outline 300-mil

Package Using 25-mil Center-to-Center

Spacing

description

A FIFO memory is a storage device that allows

data to be written into and read from its array at

independent data rates. The SN74ACT7814 is a

64-word by 18-bit FIFO for high speed and fast

access times. It processes data at rates up to

50 MHz and access times of 15 ns in a bit-parallel

format.

Data is written into memory on a low-to-high

transition at the load clock (LDCK) input and is

read out on a low-to-high transition at the unload

clock (UNCK) input. The memory is full when the

number of words clocked in exceeds the number

of words clocked out by 64. When the memory is

full, LDCK signals have no effect on the data

residing in memory. When the memory is empty,

UNCK signals have no effect.

Status of the FIFO memory is monitored by the full (FULL), empty (EMPTY), half-full (HF), and

almost-full/almost-empty (AF/AE) 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. The HF

output is high when the FIFO contains 32 or more words and is low when it contains 31 or fewer words. The

AF/AE status flag is a programmable flag. The first one or two low-to-high transitions of LDCK after reset are

used to program the almost-empty offset value (X) and the almost-full offset value (Y) if program enable (PEN)

is low. The AF/AE flag is high when the FIFO contains X or fewer words or (64 – Y) or more words. The AF/AE

flag is low when the FIFO contains between (X + 1) and (63 – Y) words.