Roadmap Phase 2 asks to validate N_INPUTS/N_NEURONS/PARALLEL
combinations, including non-exact-multiple configurations. Added
sim/parameter_sweep_tb.v with 5 configs (two exact-multiple sanity
checks, two non-exact-multiple, one degenerate PARALLEL>N_INPUTS),
using a cycle-count watchdog instead of a blocking wait so a hanging
config is reported rather than hanging the simulation.
Findings (RTL unchanged, core datapath left untouched):
- GROUPS = N_INPUTS / PARALLEL truncates: when N_INPUTS is not an
exact multiple of PARALLEL, the remainder inputs are silently
never summed (confirmed 30/8 -> 6 dropped, 20/16 -> 4 dropped).
- PARALLEL > N_INPUTS gives GROUPS=0, and the controller's
group_index == GROUPS-1 terminal condition is never met: the
neuron hangs forever (confirmed via watchdog timeout).
Documented both as findings under Phase 2 in
docs/FPGA-NeuralNetwork-Engine.md for follow-up in Phase 3/7.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WQV3vS9TXaGDJ5cRfnfidt
