Regression Based Mixed Signal Verification of an Ambient Light Sensor Interface

This paper discusses about Mixed Signal Design Verification Methodology (MSDV) which has been adopted for verifying Ambient Light Sensor (ALS) Interface. Analog sub blocks used within the system are modelled using SystemVerilog. Block level verification is done by performing equivalence checks between Analog schematics and behavioral models with the help of self-checking testbenches. The entire process of block level verification is well automated by means of script-based regressions. System level design constitutes of both analog as well as digital blocks. Traditional mixed mode simulations are time consuming which is mainly due to the huge netlist generated. This limits the number of test scenarios that can be verified. In system level simulations, the above-mentioned drawback can be resolved by choosing between transistor level schematic view or behavioral model view for the analog sub blocks based on the test case targeted. Automation of analog block level verification using regressions reduces the total debug time by 99% which ensures that more test scenarios are covered. Assertions in system level verification are used to check the integrity of analog to digital interface signals. The MSDV methodology adopted here thus offers a faster verification approach and guarantees a bug free and reliable system.