No, it's not the GPU ISA. Complex chips tend to embed management cores, for example to handle power management or various configuration operations across the ch

No, it's not the GPU ISA. Complex chips tend to embed management cores, for example to handle power management or various configuration operations across the chip. NVidia used a proprietary ISA (Falcon) for such cores, and moved to RISC V. But this is independent from the GPU ISA itself, which remains NVidia proprietary. So in the end, in their embedded SoC you can find (at least) 3 ISAs: ARM for CPU, NVidia proprietary for the GPU, and RISC V for NVidia management cores. And it's likely there are more, for example for audio DSP and other IPs embedded programmable units.