Saturday, October 9, 2010
Scoreboard for checking interrupts !!!
Architecting a good interrupt monitor and an interrupt scoreboard is very essential to hit bugs and close coverage on the interrupt logic of the design.The architecture is very simple, you need to have a shadow register for your interrupt status register and predict the interrupt by writing in to this register, the predication should be done in the transactor based on the transaction class attributes for a regular transaction, error condition ect .. The interrupt scoreboard should reside on the passive interrupt monitor which reads the shadow register as well as the original hardware register and the mask and makes a comparison on the expected interrupts and flags an error if the interrupt is mismatching. The monitor should have options to clear the interrupt when it is available or accumulate interrupt and clear it when it is required. At end of the simulation a comparison of shadow register and real interrupt status register needs to be done to check if all the expected interrupts have arrived and flag appropriate error messages.