Requirements for register-level/NxCore-like programming in Lava

[awintel]

Starting this discussion to collect requirements for how to support low-level register-level programming of Loihi NeuroCores similar to the former NxCore API.

Clearly, the purpose of Lava is to up-level of neuromorphic HW but for certain use cases it is still desirable to support register-level programming via Lava (i.e. validation). In particular, many former NxSDK users have apparently developed algorithms at the NxCore/register-level for Loihi 1 which they would like to reuse even in Lava.

The plan so far was to provide Loihi 1 and Loihi 2 NeuroCore Lava Processes that give access to all core features as well as all the constraints which normally the compiler would handle automatically for other processes. Instead, these types of processes would not have to be "compiled" or partitioned, only mapped to a corresponding physical core in Loihi.

Naturally, the original plan was to improve the old NxCore-like NeuroCore programming API while enabling it in Lava. However for backwards compatibility, there should also be a way to run old NxCore-level algorithms as-is through Lava which out any rewrite.

Please drop your thoughts below (e.g. what such an "NcCore API" in Lava should support) and if you would be interested to help.

Thanks!