FIFOs Memory

1. What are FIFO Memory ICs?

‌Basic Concepts‌

FIFOs (First-in-First-out Memory) is a memory dedicated to data buffering, ensuring that data is read in the order in which it is written to avoid data sequence disorder.

 

‌Core Function‌

It is used to solve the data transmission problem between modules of different speeds, such as the communication between high-speed processors and low-speed peripherals, to achieve synchronization and buffering of data streams.

 

2. What are the Technical Features of FIFO Memory ICs?

1) ‌Storage Structure‌

Supports multiple data widths (such as 18 bits) and depths (such as 256×18), and flexibly adapts to different data packet sizes.

 

Data item storage requires a 4-byte alignment to meet hardware access efficiency requirements.

 

2) ‌Working Mode‌

‌Synchronous FIFO‌: Relying on clock signals to control read and write timing (such as SN74ACT7805 series).

‌Asynchronous FIFO‌: Read and write operations use independent clocks, suitable for cross-clock domain scenarios.

 

3) ‌Control Flags‌

Provide programmable flags (such as empty/full/half-full status bits) to assist the system in real-time monitoring of data buffer status.

 

3. What are the Typical Specifications of FIFO Memory ICs?

‌Memory Depth‌: 256×18 bits (about 4.5K capacity)

‌Data Rate‌: Up to 25MHz

‌Voltage Range‌: 4.5V – 5.5V (compatible with TTL level)

‌Package Style‌: 56-SSOP (surface mount)

‌Operating Temperature‌: Industrial Grade: 0°C – 70°C

 

4. What are FIFO Memory ICs Used for?

‌High-speed Data Acquisition System‌

As a buffer between ADC/DAC and processor to ensure continuous transmission of real-time data (such as oil cyber data acquisition system).

 

‌Multi-processor Communication‌

Coordinate data flow in heterogeneous systems such as DSP and FPGA (such as TI uPP interface and FPGA communication).

 

‌Real-time Operating System (RTOS)‌

Support efficient communication between processes/threads (such as IPC mechanism in QNX and Zephyr).

 

5. Key Points for Selecting FIFO Memory ICs

‌Rate Matching‌: Select a model that supports single/double data rate according to the system clock.

‌Expandability‌: Some models support multi-FIFO cascading to increase buffer depth.

‌Power Consumption Control‌: The static current is as low as 400μA, suitable for embedded low-power scenarios.

Note: The SN74ACT series (such as SN74ACT7805 and SN74ACT7814) of current mainstream manufacturers such as Texas Instruments are commonly used models in the industry.