AMD Publishes Vega 7nm ISA Documentation - 300 More Pages Of GPU Docs

Beyond AMD's open-source graphics driver stack of the past decade, part of their original open-source plans have also involved providing public (NDA-free) GPU hardware documentation. That has come with time though the documentation drops are not coordinated in-step with code drops. Out today, for example, is the ISA documentation on Vega 7nm.

Back in 2017 was the timely release of the Vega ISA documentation and earlier this summer was even the RDNA 1.0 ISA documentation but missing out until now was the Vega 7nm ISA documentation.

Under AMD's GPUOpen umbrella they now have Vega 7nm ISA documentation public. This includes outlining changes from earlier Vega GPUs around new 16-bit math instructions, register changes, global and scratch memory read/write operations, scalar memory atomic instructions, and other new instructions along with some other architectural changes.

The docs cover just the shader ISA and not all the information needed to write your own AMD Radeon driver -- for that their current methodology has been interested users can check out their open-source Linux driver code. With some generations AMD has published more hardware documentation but in recent years they have just focused on getting the shader ISA out there and leaving the rest up to the Linux code documentation and register header files, etc. Due to the review/legal time spent otherwise also needing to be done clearing more hardware documentation for release and that engineering time arguably better spent working on the Linux driver code itself.

Those wanting to see 299 more pages of AMD GPU documentation goodness can find these Vega 7nm ISA shader docs at GPUOpen.com (PDF).

Presumably this documentation will remain relevant for the yet-to-ship and somewhat mysterious Vega-based Arcturus accelerator. That Arcturus factor would also lend a possible explanation why AMD is publishing the Vega 7nm ISA documentation now at the end of 2019 -- months after Navi/RDNA has been shipping and even there already having RDNA 1.0 docs public.