72241L15PF

Logic - FIFOs Memory

FIFO, or first in first out, is an algorithm for storing and retrieving data or objects in which the first element added is the first one to be removed. FIFOs are datastructures used to store and transfer data between clock domains. FIFO memory makes sure that the synchronization between different clock domains is maintained and that data is stored in and retrieved from the same clock-ticking source. For embedded applications having memory block that is easily configurable, 72241L15PF is commonly used.

72241L15PF application field and working principle

72241L15PF is a 64K*16 FIFO memory that supports byte, line, sector and page write and byte, line, sector and page read operations. It has an operating voltage of 3.0V and an access time of 21ns. It can be used in applications such as ATA, PC card controller, SCSI, Serial, Digital I/O, etc. It has two ports - port A and port B, and each port flexibly supports Read and/or Write operations. The mode select pins can be used to select the operating mode - Asynchronous or Page mode.

In operation, data is written and read from the ports A and B at specified intervals. In Asynchronous mode, data is transferred one word at a time whereas, in Page mode, data is transferred one page at a time, with a maximum of 4 words per page. The FIFO memory can be programmed with different line sizes for each port. The programming options available are 8, 16, 32, and 64 words per line.

When programmed, the FIFO memory operates by storing data in and retrieve data from a buffer in a First-In-First-Out fashion. The first data stored in the buffer is the first data read out of the buffer. Similarly, the last data stored in the buffer is the last data read out of the buffer. In addition, the FIFO has certain features like status and control registers to monitor the FIFO memory status, and control the length of the FIFO buffer.

The status register provides numbers of words that can be read or written at a particular time, while the control register is used to control how much data is read or write from or to the memory. It is possible to configure the FIFO memory as full/empty, or almost-full/almost-empty. In this configuration, the status register can be used to signal when the FIFO memory is full or empty, or almost full or almost empty, providing better control over the data transfer.

Apart from the standard FIFO operations, the FIFO memory also helps to synchronize the data between slow and fast peripherals. Due to its asynchronous nature, data is written in the FIFO memory without the need for the peripheral to enter an active state, thus making it possible to write data even in power-down mode. The FIFO memory also supports auto-reload, which can be used to automatically reload the FIFO memory when it is empty.

The FIFO memory also helps to reduce high clock skews, which can occur when transferring data between two different clock domains. When data is written and read from the FIFO memory, the clock skews can be compensated by delaying the output of the FIFO memory to the receiving peripheral clock domain. Thus the FIFO memory provides a higher degree of flexibility in terms of transfer speeds and data synchronization.

In summary, the 72241L15PF FIFO memory is used in applications as an efficient tool for storing and retrieving data. It enables data synchronization between two clock domains, reduces clock skews, provides various write/read configurations, and offers numerous status and control registers to assure data protection. By leveraging FIFO memory data transfers are fast and reliable, helping to maximize system performance.