They are relevant for the exam, but maybe not the most important topics. They are also an outlook on the RoSy lecture where processor architecture and system software are in the focus. The two lectures are connected by using digital circuit design (which is the major focus of DiRa) for the design of processors.
What is needed for the DiRa exam of this chapter? Well, we do not really discuss the micro architecture of processors, i.e., the circuit design, but just the macro architecture, which means the instruction set. You should therefore be able to read and write such programs. For the execution of these programs, we have the programmer's point of view which means that we assume that in each cycle, one instruction is executed. In reality, this is not the case, but that is the topic of RoSy.
If such an exercise should be part of the exam, we will add a sheet of paper with all of the instructions. So, you don't have to remember them all, but it is recommended to have seen and understood them during the exam preparation. As said, the single-cycle execution of the instructions should then be sufficient.