What is SDF ?
Standard Delay Format (SDF) is an IEEE standard (IEEE 1497) used extensively in electronic design automation (EDA) for representing timing information associated with digital circuits. It is in ASCII format and includes path and interconnect delays and timing constraint checks.
What are timing checks ?
Timing checks in digital design are critical for ensuring that a circuit meets its specified timing requirements. They help verify that signals propagate through the circuit within the allowed time constraints, preventing issues such as setup and hold time violations.
Timing checks must be placed inside a specify block in a Verilog module.
specify
// Timing check statements
endspecify
In Verilog, conversion functions are used to convert data between different formats, specifically between integers, real numbers, and bit representations. These functions facilitate the manipulation and representation of data types within a simulation environment.
$rtoi
Converts a real number to an integer. This function is used when you want to truncate the fractional part of a real number and obtain its integer representation.
integer $rtoi(real_val); // For example, 192.15 becomes 192
In Verilog, the strength of driving a net refers to the relative power or capability of a driver to influence the value of a net.
Two types of strengths can be specified in a net declaration
Charge Strength
Charge strength is specifically used with trireg nets to model charge storage. It indicates the relative size of the capacitance associated with the net indicated by either small, medium or large.
What is a stack or LIFO ?
LIFO, which stands for Last In, First Out, is a data organization method commonly used in digital design and computer science. The LIFO principle dictates that the most recently added item is the first one to be removed. This concept is analogous to a stack of plates, where the last plate placed on top is the first one to be taken off.
How does it work ?
LIFO is the fundamental principle behind the stack data structure:
- New elements are added to the top (push operation)
- Elements are removed from the top (pop operation)
- The most recently added element is always at the top
