This week I change my focus and prioritized on working on the design report that is due this weekend. After working on the design review presentation and reading the feedback, we realized there were some details we needed to flesh out before moving forward with implementation. While talking about these details, I was able to get a better understanding of how the APU will interact with the rest of the system. The APU is a purely a read-only sub-system so it will not have any write-backs or interrupt complications like the PPU. This will help with planning and designing interactions amongst the subsystems.
Additionally, from the feedback, we went back and reviewed our verification standard and memory storage. After reviewing the manual again, we realized that we needed a micro SD card to act as our persistent memory because although the board has flash capability, it doesn’t have the storage on the board. Therefore, we have put in a request for a micro SD card so we can begin loading the games and looking at the memory transfer protocols. Additionally, we realized that was no clear “block RAM” on the board so we decided to move our working memory to SDRAM.
For the design document, I wrote the introduction, the APU sub-system description, and the project management.
Before focusing a majority of my time on the design report, I had a chance to start outlining the decoders’ access to memory and wrote out what each bit meant for that voice. By the end of Spring Break, I hope to have:
- Written out the decoders for the APU
- Designed how the mixer for the APU
- Implemented the CPU
