Recently it has been talking to Ars Technica about something else dubbed "heterogeneous Uniform Memory Access" (hUMA) which is its take on HSA. HSA involves developing systems with multiple different kinds of processor, connected together and operating as peers. Normally it is CPUs and GPUs.
Armed with another set of acronyms AMD talks about splitting workloads between a CPU and a GPU, and the creation of a general purpose GPU (GPGPU). But a GPGPU is awkward for software developers, some of whom might think that GP stands for guinea pig and others are not happy that the CPU and GPU have their own pools of memory.
HUMA is AMD’s way around this problem. Using HUMA, the CPU and GPU share a single memory space and the GPU can directly access CPU memory addresses, allowing it to both read and write data that the CPU is also reading and writing. It is also cache coherent so the CPU and GPU will always see a consistent view of data in memory. If a processor makes a change then the other processor will see it.
We will first see HUMA in the chip codenamed Kaveri. It mixes up to three compute units using AMD's Bulldozer-derived Steamroller cores with a GPU. The GPU will have full access to system memory. It should be out in the second half of the year.
It appears likely that the chip AMD is designing for the PlayStation 4 later this year will also be a HSA system.