Chip Design and Verification > 2 Adding some registers > 202 Updating test
Updating the test
Adding more features to the DUT is all nice, but this has to be reflected in the verification.
As the DUT now looks different, the interface needs to be adapted. It no longer connects to the ALU, but to the gbprocessor.
Initially, register A starts at value 0x00. When the instruction ADC H is executed, then register A gets incremented with 5.
Have a closer look at the waveforms. After the ADC operation, the value of register A is updated. However, this results in a consecutive change of the ALU output ‘Z’.
Why is this new value not stored in register A ?
Repeating this instruction 3 more times will result in a change of the value in register F.
Find an explanation why register F changes.