Synchronous FIFO
- introduction. Synchronous FIFO plays an important role in the data buffer. Compared to asynchronous FIFOs, synchronous FIFO structures are simpler and are synchronous circuits under a single clock domain.
- RTL code. Enter the clock, reset, 8-bit data, write enable read. Output 8 bits of data, full flag. ...
- Simulation results
What is an asynchronous FIFO?
An Asynchronous FIFO refers to a FIFO where the data values are written to the FIFO at a different rate and data values are read from the same FIFO at a different rate, both at the same time. The reason for calling it Asynchronous FIFO, is that the read and write clocks are not Synchronized.
How does a synchronizer work in FIFO?
In order to avoid such scenarios, the reading and writing is done via a synchronizer. The synchronizer ensures that read and write pointers calculations are consistent and data in FIFO is not accidentally overwritten or read twice.
What is the difference between clocked and synchronous FIFOs?
Clocked and synchronous FIFOs are essentially the same, except that clocked FIFOs were the first FIFOs with 2 clock interfaces released by Cypress. Later generations of clocked FIFOs were named "synchronous" FIFOs. Synchronous FIFOs have a clock on each port with its associated enable signals.
What is synchronous FIFO memory in C++?
FIFO memory consist of write pointer ,read pointer, write address and read address synchronous FIFO mean read operation and write operation asserted depends on clk. read and write pointer should be one bit higher than read and write address.
What is asynchronous FIFO?
An asynchronous FIFO refers to a FIFO design where data values are written to a FIFO buffer from one clock domain and the data values are read from the same FIFO buffer from another clock domain, where the two clock domains are asynchronous to each other.
What is difference between synchronous and asynchronous FIFO?
FIFO can be either synchronous or asynchronous. The basic difference between them is that the entire operation of synchronous FIFO is entirely dependent on the clock where as the write operation and read operation of asynchronous FIFO are asynchronous to each other.
How do you know if FIFO is synchronous?
The synchronous FIFO design involves implementation of a memory array and associated write/read control logic at the RTL level using Verilog HDL. A verification environment [7] is developed using SystemVerilog and the UVM library to verify the functionality of the Synchronous FIFO design model.
How do you calculate synchronous FIFO depth?
Example : FIFO Depth Calculation If if we have alternate read cycles i.e between two read cycle there is IDLE cycle. If 10 IDLE cycles betweeen two read cycles . FIFO DEPTH = B - B *F2/(F1*10) .
What is meant by synchronous and asynchronous?
The key difference between synchronous and asynchronous communication is synchronous communications are scheduled, real-time interactions by phone, video, or in-person. Asynchronous communication happens on your own time and doesn't need scheduling.
What is VLSI FIFO?
FIFO means First-In First-Out. A FIFO is a structure used in hardware or software application when you need to buffer a data. Basically, you can think about a FIFO as a bus queue in London. The people that arrive first is the one who catch the bus first…. Figure1 – FIFO example at bus Stop.
Why do we need synchronous FIFO?
Basically Synchronous FIFO are used for High speed systems because of their high operating speed. Synchronous FIFO are easier to handle at high speed because they use free running clocks whereas in case of Asynchronous FIFO they uses two different clocks for read and write.
What is a FIFO buffer?
A FIFO is a special type of buffer. The name FIFO stands for first in first out and means that the data written into the buffer first comes out of it first. There are other kinds of buffers like the LIFO (last in first out), often called a stack memory, and the shared memory.
How do you determine FIFO?
To calculate FIFO (First-In, First Out) determine the cost of your oldest inventory and multiply that cost by the amount of inventory sold, whereas to calculate LIFO (Last-in, First-Out) determine the cost of your most recent inventory and multiply it by the amount of inventory sold.
What is burst length in FIFO?
Burst Length = No. of data items to be transferred = 120. There are no idle cycles in both reading and writing which means that, all the items in the burst will be written and read in consecutive clock cycles.
What is FIFO overflow and underflow?
An overflow occurs when an attempt is made to write new data to a full FIFO. Similarly, an empty FIFO has no data to provide on a read re- quest, which results in an underflow.
What is FIFO memory?
First-In, First-Out (FIFO) memory devices are used for short-term storage of digital information, with retrieval of information occurring in the same order and sequence that the information was stored.
1. What is FIFO
FIFO is a first in first out data buffer, which is widely used in logic design. FIFO design can be said to be a common sense design that logic designers must master. FIFO is generally used to isolate places where the read-write bandwidth on both sides is inconsistent or the bit width is different.
2. Design method of synchronous FIFO
Working principle of FIFO read-write pointer (read-write pointer is read-write address):
3. Other
After understanding the design method of synchronous FIFO, it is relatively simple to design asynchronous FIFO, which mainly solves the problem of cross clock domain comparison of read and write pointers in asynchronous FIFO. The next article will analyze and verify the design of asynchronous FIFO
