[SOLVED] difference between simulation and emulaiton

[cyboman]

i'm slowly learning digital design and verification. i'm currently reading a book on OVM (very difficult read) and it states that there might be differences when simulation is used vs emulation. at this points i don't care what is the difference in results. but i care about what is the difference? to me simulation and emulation meant exactly the same thing. and it seems to me that i misunderstood it. i would really appreciate an explanation of what is the difference between simulating the design and emulation the design.

any help is appreciated

 

[srizbf]

simulation mimicking the target at functional level.
emulation is including the hardware characteristcs

 

[cyboman]

simulation mimicking the target at functional level.
emulation is including the hardware characteristcs

can you elaborate more on this. i'm not sure i fully understand your answer. what do you mean by mimicking hardware at the functional level? what do you mean by 'including the hardware characteristics'. what characteristics are you talking about? can you give some examples.

 

[skyfaye]

Simulation uses software models to validate the design. The library model characteristics (propagation delay, setup/hold time, etc.), for example, are usually very close to the real silicon. Simulation provide a great control environment for debug (you have visibility to all the signals) but has poor run-time speed.

Emulation do not use any models. The actual design is synthesis/par for the targeted FPGA in the emulation board. Emulation provide excellent run-time speed (up to full clock speed) but poor debugging support (can't see inside the FPGA really). Usually emulation is used when you're designing a complex ASIC and want to have a more confidence level that the chip doesn't have any bugs. With at-speed emulation testing, you can uncover many hard to catch corner-case bugs that simulation can't. For example, 1 sec of simulation time will take weeks to complete, whereas, it will take 1 sec in emulation.

- Hung

 

[cyboman]

Simulation uses software models to validate the design. The library model characteristics (propagation delay, setup/hold time, etc.), for example, are usually very close to the real silicon. Simulation provide a great control environment for debug (you have visibility to all the signals) but has poor run-time speed.

Emulation do not use any models. The actual design is synthesis/par for the targeted FPGA in the emulation board. Emulation provide excellent run-time speed (up to full clock speed) but poor debugging support (can't see inside the FPGA really). Usually emulation is used when you're designing a complex ASIC and want to have a more confidence level that the chip doesn't have any bugs. With at-speed emulation testing, you can uncover many hard to catch corner-case bugs that simulation can't. For example, 1 sec of simulation time will take weeks to complete, whereas, it will take 1 sec in emulation.

- Hung

thanks for the explanation. can you go into more details about what an emulation board is. the book mentions it only briefly but doesn't explain its purpose, and i have never used one or even seen one. as far as i understand it is some sort of a board into which i download my design and run it, but then how is it different from a regular FPGA?

any help is appreciated

 

[skyfaye]

One type of emulation system is where you have an emulation board with several FPGAs on it. Depending on the resource (FF, memories, serdes, etc.) requirement, you may need to paritition your design onto multiple FPGAs. The vendor that selling the emulation system will provide you with this emulation board. See the following link a one type of emulation system from Cadence.

https://www.cadence.com/newsletters...ulation_Acceleration_Emulation_Technology.pdf

- Hung

 

[cyboman]

One type of emulation system is where you have an emulation board with several FPGAs on it. Depending on the resource (FF, memories, serdes, etc.) requirement, you may need to paritition your design onto multiple FPGAs. The vendor that selling the emulation system will provide you with this emulation board. See the following link a one type of emulation system from Cadence.

https://www.cadence.com/newsletters...ulation_Acceleration_Emulation_Technology.pdf

- Hung

thanks a lot. your answers really helped.