What is “RTL” coding in Verilog?

When we talk about RTL (Register-Transfer Level) in Verilog, we refer to a specific abstraction level used in hardware description languages like Verilog. It’s a design style that focuses on describing the digital circuit’s behavior in terms of data transfers between registers and the combinational logic that operates on this data.

At the RTL level, we represent the design using registers to store data and combinational logic to manipulate this data. You’ll see that it abstracts away the specific details of the underlying hardware implementation and provides a higher-level view of the circuit’s functionality.

In RTL Verilog, you describe how data moves from one register to another and how it is processed by the combinational logic in between. The language gives us constructs to describe clocked operations, where data is synchronized with a clock signal, as well as combinational operations, where the output depends only on the current input values.

RTL is an important level in hardware design because it is closer to the actual hardware implementation. This allows RTL code to be synthesized, meaning it can be automatically converted into a gate-level representation, which is the actual physical implementation of the design on hardware components like transistors and flip-flops.