Lab credit and the course test are completely independent.
Each lab will hold one assignment (possibly broken down into several steps). The assignments are incremental, which means that your code and knowledge obtained when solving one assignment may be required for the subsequent assignment(s). The individual assignments lead to the final home assignment. To receive a credit for the labs, you need to complete all the individual assignments from all labs and successfully present the final home assignment to your lab teacher.
Under regular circumstances, the individual lab assignments are solved during the labs. If one fails to complete the assignment during the labs or misses the class altogether, the assignment should be finished at home. In any case, the assignments has to be uploaded to ReCodEx before midnight of the day when the next lab starts.
The final home assignment has to be presented in person to your labs teacher. Individual labs will have individual terms for presentations (announced by the lab teacher before the summer examination period). Primary criterium for the credit is that your solution is fully functional. Secondary criterium is the code quality. Solutions which severely violate good coding practices will not be accepted.
Please, make yourself acquainted with authors' ethical guideline. It might prevent future misunderstandings regarding the authorship of your lab assignments.
The exam will be either a test, probably written in labs and evaluated by a computer (the details are still being ironed out). A few examples of testing questions will be presented in the last lecture. The questions will target mainly your understanding, not your memorized knowledge. In other words, you do not remember exact constants or precise names of MIPS instructions; however, you need to understand the concepts even to solve simple computational/algorithmic assignments (e.g., put given instructions in the right order).
Exam dates will be announced before the summer exam period in SIS where you need to enroll for them. Exams will be added if needed, but do not rely on having any terms in September. The credit is not required for the exam (they are treated separately).