Computer architecture (I think my uni named it comp org) was one of my toughest courses in undergrad! It steered me away from hardware. I now wonder if that is still the case today? ARM has exploded onto he scene and I'm fascinated by the sheer amount of development going on in the chip space.
Many principles in computer architecture were discovered loooong ago. Pipelining, multi-core cpu's, virtual memory, various types of caching, etc etc. It's just that today's tech squeezes orders of magnitude more logic into a mm^2. So the scale of what's considered a small or big project has changed.
Obviously that requires a more rigorous approach. So I'd expect courses in this field to put more emphasis on testing & validation methods (and tools to do that).
> ARM has exploded onto he scene
ARM is mature tech now. I'd say most excitement is around RISC-V these days. Well that and GPUs, AI accelerators, FPGAs, manycore cpus, photonics, quantum computing, ...