What is 1ps in Verilog Timescale? Time Units, Resolution, & Examples

What does 1ps mean?

1ps stands for 1 picosecond. The abbreviation “ps” means picosecond, or 1/10 (1 trillionth) of a second. In the programming language Verilog, 1ps is a unit for the `timescale compiler directive, which sets the default unit of time for a simulation and the resolution to which outputs are rounded. The units are seconds (s), milliseconds (ms), microseconds (us), nanoseconds (ns), picoseconds (ps), and femtoseconds (fs).

How to Use the Verilog Timescale Directive

Choose your units of time and resolution. In Verilog, the timescale directive is written as `timescale integer [time unit] / integer [resolution]. When choosing your units, always put the larger one first. The general time scale must be divisible by the resolution. The first unit is how time is measured, and the second is how precise your recordings are. The ` symbol, or backtick, lets the program know that you’re using a compiler directive. It introduces the `timescale directive, as well as `include, `resetall, `define, and others.

Choose your integers (order of magnitude). Finish setting the timescale by choosing one of three integers to put before your units: 1, 10, or 100. By adding an integer you can control how much time makes up a single unit or how many units go into the resolution. For example, if you write the directive `timescale 10ns / 1ns, then for every 10 nanoseconds the output value will be rounded to the nearest nanosecond. A common timescale is 1ns / 1ps, which means at each nanosecond there is an output rounded to the nearest picosecond.

Write your test bench module. Test benches run a simulation of your design, and check the outputs. Set up your module by writing: `timescale [unit of time]/[unit of precision] module tb; reg val; initial begin val<=[where you want to start];

Set delays by writing #[real number] before your functions. To program when your data is recorded, write the operator #[real number] and then a function. The operator # (AKA the delay) is multiplied by the time unit, then rounded to the nearest time precision unit (resolution). For example, you could write #5 $display (“T=%0t At time #5”, $realtime); val<=1; If your `timescale is 1ns/1ns, then your output would be 1(ns) * 5 = 5 since it’s rounded to the nearest nanosecond. If your `timescale was 10ns/1ns, then your output would be 10(ns) * 5 = 50. If your `timescale was 1ns/1ps, then your output would be 1000ps (AKA 1ns) * 5 = 5000 to convert it to picoseconds.

Set the end time and add the ending code. To end the simulation, write #[real number] before the function $display (“T=%0t End of simulation”, $realtime); then write the codes “end,” then “endmodule”. “End” closes the block “initial begin,” and “endmodule” closes the “module” block. Your entire simulation may look like this: `timescale 1ns/1ps module tb; reg val; initial begin val<=0; #1 $display (“T=%0 At time #1”, $realtime); val<=1; #5 $display (“T=%0t End of simulation”, $realtime); end endmodule

Other Meaning of 1ps

1ps can mean first-person shooter when referring to gaming. Video games that are in first-person perspective are often called first-person shooters, more often abbreviated as FPS. Occasionally, they’re also abbreviated to “1ps.”

In math, IPS stands for inches per second. Sometimes, IPS refers to a unit of measurement for acceleration, which is inches per second. When it’s being used for a change in velocity (acceleration), it’s written as inches per second.

IPS can also refer to a kind of LCD screen. IPS (in-plane switching) monitors are a kind of LCD screen where liquid crystals are sandwiched between two planes of glass.

IPSs are a kind of computer security system. IPS can also mean “intrusion prevention systems,” which block attacks on networks and computers.