[alessiomangone]

The simulation-only CHECK_ASSERTIONS block of core_region (rtl/core_region.sv:490-493) stops the run with ERROR_2 and $finish on any core data access between CLUSTER_BASE + 32'h0040_0000 and CLUSTER_BASE + 32'h0A00_0000. The cluster's own window, however, starts at CLUSTER_BASE + (cluster_id_i << 22) (rtl/cluster_bus_wrap.sv:120, rtl/xbar_pe_wrap.sv:59): for cluster_id_i == 0 it lies below the refused range, for any other cluster_id_i it lies inside it, peripherals included. In a multi-cluster instance, every cluster but the first thus stops the simulation on its first access to its own control unit.

This keeps the check's purpose - the other clusters' windows are still refused - and exempts the cluster's own 4 MB window, from CLUSTER_BASE + (cluster_id_i << 22) to + 32'h0040_0000, with the same expression the two wrappers use.

Verified: I have carried this change as a local patch since 2026-09-04 on a 2x2 array of PULP clusters, where the offload test now runs on every cluster under QuestaSim 2026.1_2 and Verilator 5.050; without it, the simulation stops at the second cluster's end-of-computation write with ERROR_2.

[alessiomangone]

Closing this: it is not needed in the configuration this repository builds.

The check sits under ifndef CLUSTER_ALIAS, and bender-common.mk defines CLUSTER_ALIAS globally, so the check is never compiled there. I hit it because my build took CLUSTER_ALIAS only from pulp_soc_defines.sv, which pulp_cluster_package.sv includes. QuestaSim compiles each file as its own compilation unit, so that define does not reach core_region.sv or data_periph_demux.sv; Verilator, with a single unit, does see it. I now pass the define globally, as bender-common.mk does.