21 Interfaces(NOT ASSESSED)

Question 1

Why interface?

Answer 1

It is easy to end up with systems in which many signals are passed between two blocks. SystemVerilog provides an Interface construct, which offers a new paradigm for modelling large and complex design. The interface construct allows signals to be collected together even though they are moving in different directions

Question 2

How are modules grouped together?

Answer 2

Instantion, long-winded process?

Question 3

Instantiation problems?

Answer 3

• Ports name, types and mode are defined in multiple modules.
• Tedious and redundant process.
• There is a risk of mismatch declarations in different modules.
• Even a small change in the design specification can require modifications in multiple modules.
• Not problems approach for reusability in other projects.

Question 4

What does an interface allow you to do?

Answer 4

• An interface allows the encapsulation of signals into a block, which is known as encapsulation of communication
• The grouped signals can be represented as a single port
• All related signals are grouped together to form an interface
• They improve the maintainability and readability of designs, and reduce the amount of code require to model a design.
• They can contain parameters, variables, constants and assignments
• The interface allows reusability in other projects

Question 5

A module may have more than one interface

Answer 5

Question 6

Syntax for interface declaration:

Answer 6

Question 7

Master and Slaves?

Answer 7

Question 8

The interface sBus?

Answer 8

Question 9

How are the ports defined on bus?

Answer 9

Question 10

Overall bus script?

Answer 10

Question 11

Answer 11

Question 12

Answer 12

Question 13

Answer 13

Question 14

Overall interface design?

Answer 14

Question 15

It is possible to define the modport in the definition of the module.

master module

Answer 15

It is possible to define the modport in the definition of the module. The master module will use the port configuration from masterPorts defined by modport in the interface. This configuration is accessed with “.” followed by the modport configuration.

Question 16

It is possible to define the modport in the definition of the module.

Slave module

Answer 16

Question 17

Slave and master with top modules

Answer 17

Question 18

Interfacing key details

Answer 18

• Instances are defined in a similar way as modules, but there are difference between them
• Interfaces cannot contain instances of modules
• Interfaces can be used as a module port. This allow interfaces to represent communication channels between modules
• It is illegal to leave an interface port unconnected
• Ports signals not declared in the modport are not visible to that connection to the interface
• A modport can be selected in either the module instance or the module definition, but not both