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Is it possible to synchronize the data just with SDC constraints?
There is 1-bit data from clk1 to clk2. I know this is a kind of asynchronous scenario and the traditional method is the use of 2 FFs or an asynchronous FIFO to synchronize the data. However, since these two clocks have a fixed phase difference, so is it possible to synchronize the data JUST with SDC constraints?
How to correctly specify timing constraints via SDC?
If you use any RTL wrapper around flip-flops – set the source of the generated clocks to be the internal Q pin of the flip-flop, not the output pin of the wrapper. If you follow these simple rules you need not worry about any buffers added by the synthesis or P&R tools.
What are constraints for source clock and derived clock?
Basically clk2 rises at the 2nd edge of clk1, falls at the 3rd edge and rises again at the 4th edge. The 1-bit data has a half clock cycle to arrive the target FF. By the help of our constraint, the tool will perform setup/hold timing checks accordingly.
Are there different SDC tools for timing analysis?
There are also some differences between different tools for implementation and timing analysis of different vendors (despite Synopsys offering a SDC parser source code), but I hope that they are mainly a syntax issue which can be looked up in the documentation.
How are the flip flops connected in FPGA synchronizer?
In this modifed version, the data input to the first flip flop is tied to GND, and instead the incoming reset signal is connected to asynchronous preset signals of each flip-flop in the synchroniser.
Which is better a FIFO or a synchroniser?
Data buses – for data where you have a source that spits out data continuously or in bursts, you are arguably better off using a FIFO than synchronisers. The FIFO uses a dual-clock memory to hold the data, along with counters to keep track of how much data is in the FIFO.