What is the need of clocking blocks in SystemVerilog?
SystemVerilog adds the clocking block that identifies clock signals, and captures the timing and synchronization requirements of the blocks being modeled. A clocking block assembles signals that are synchronous to a particular clock, and makes their timing explicit.
What is the difference between the clocking block and Modport?
Clocking block is used to introduce input/output sampling/driving delays. Modport defines directions of signals and can be used to represent set of signals.
How do clocking blocks avoid race conditions?
1. The same signal is driven and sampled at the same time. => To avoid this race condition, a clocking block in interface is used as it provides an input and output skews to sample and drive, respectively. 2.
Which region clocking block is executed?
Clocking Block samples input data from Preponed Region, whereas in normal always block, there are always chances of race condition.
Why are clocking blocks used?
A clocking block is a set of signals synchronised on a particular clock. It basically separates the time related details from the structural, functional and procedural elements of a testbench. It helps the designer develop testbenches in terms of transactions and cycles.
What is clocking block and what are the benefits of using clocking blocks inside an interface?
Use within an interface
Hence declaring a clocking block inside an interface can help save the amount of code required to connect to the testbench and may help save time during development. Signal directions inside a clocking block are with respect to the testbench and not the DUT.
What is input skew and output skew in clocking block?
If an input skew is mentioned for a clocking block, then all input signals within that block will be sampled at skew time units before the clock event. If an output skew is mentioned for a clocking block, then all output signals in that block will be driven skew time units after the corresponding clock event.
What is the use of Modports?
Modports in SystemVerilog are used to restrict interface access within a interface. The keyword modport indicates that the directions are declared as if inside the module.
Why always block is not allowed in program block?
As part of the integration with SystemVerilog, the program was turned into a module-like construct with ports and initial blocks are now used to start the test procedure. Because an always block never terminates, it was kept out of the program block so the concept of test termination would still be there.
What is program block in SV?
A module is the fundamental construct used for building designs. Each module can contain hierarchies of other modules, nets, variables and other procedural blocks to describe any hardware functionality.
How do you avoid race condition between DUT and testbench?
In test bench , if driving is done at posedge and reading in DUT is done at the same time , then there is race. To avoid this, write from the Testbench at negedge or before the posedge of clock. This makes sure that the DUT samples the signal without any race.
What is SystemVerilog interface?
A SystemVerilog interface is essentially the same as a SystemC channel. An interface encapsulates the communication information between Verilog modules. This encapsulation can include the module port definitions, tasks, functions, always blocks, continuous assignments, assertions, and other modeling constructs.
What is UVM event?
The uvm_event class is a wrapper class around the SystemVerilog event construct. … Waits for the event to be activated for the first time. wait_off. If the event has already triggered and is “on”, this task waits for the event to be turned “off” via a call to reset.
How are events involved in synchronous two processes?
An event is a static object handle to synchronize between two or more concurrently active processes. One process will trigger the event, and another process waits for the event.
Is UVM is independent of SystemVerilog?
Is UVM independent of SystemVerilog ? No. UVM is built on SystemVerilog and hence you cannot run UVM with any tool that does not support SystemVerilog.