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retroSoC/rtl/mini/integration/README.md
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maksyuki 1b4b53c650 feat: refactor RIB to RIBP: Update tests and scripts to reflect RIBP interface changes
- Updated test cases in , , , , , , , and  to replace references from RIB to RIBP.
- Modified file names and paths in tests to align with the new RIBP naming conventions.
- Ensured that all assertions and checks in the tests are consistent with the updated RIBP interfaces and functionality.
- Added a new test for migrating user core RIBP interfaces in .
2026-08-04 10:56:36 +08:00

3.3 KiB

Mini SoC Topology

soc_topology.json is the source of truth for internal Mini SoC integration that is not part of the software address-map ABI or the package pad map.

The topology generator validates rib RIB and APB target ownership against ../address_map/memory_map.json and emits generated SystemVerilog include files for ip_ribp_wrapper.sv, ip_apb_wrapper.sv, ribp2apb.sv, and retrosoc.sv. The output retains scalar interface instances and ports, so it does not depend on interface-array support in FPGA or netlist simulation tools.

The ribp_targets list uses stable response slots. Every active RIBP memory-map region must appear exactly once. Disabled targets keep their slot and interface declaration but cannot own an address region.

Each gpio_alt_functions entry defines both alternate modes for one GPIO pin. inputs are driven from the selected GPIO input, and do and oe define the peripheral output path. Values are restricted to scalar signal references and one-bit constants so malformed expressions are rejected before RTL generation.

The apb_targets list defines the stable APB response slot, timed/pure APB interface names, and corresponding active APB address-map region. The user-IP target is part of the fixed platform integration and its presence is checked against the canonical memory map.

irq_vector_width, irq_groups, and interrupts define the complete core interrupt topology. rib and apb group entries declare the wrapper output width and the associated retrosoc.sv signal. Every group bit must be present exactly once, each core-vector bit must have one source, and sources are limited to scalar signal references or one-bit constants. The generator emits the two wrapper bindings, the core-vector wiring, and simulation-only assertions. Core IRQ bits 0 through 16 retain their current compatibility mapping; additions must use currently unallocated bits and preserve the existing entries. Bits without an interrupt entry are driven low. Firmware does not expose a generic external interrupt API until the SoC includes a claim/complete interrupt controller.

user_extensions.json separately defines the supported scalar user-core and user-IP slots. generate_user_extensions.py creates isolated default routing and one explicit instance per selected slot for user_core_top.sv and user_ip_top.sv. Adding an extension therefore requires a reviewed JSON entry rather than manual edits to the SoC muxes. Each core declares whether its reset is synchronous or asynchronous so a generated legacy RIB adapter uses the same reset style and does not introduce mixed-reset paths. The module port contract remains the existing user design template contract.

clock_reset_domains.json is the checked inventory of root clock domains, reset synchronizers, and RCU PLL control crossings. It records the primitive, source file, and instance name so an RTL refactor cannot silently remove the declared reset or CDC structure. It complements, but does not replace, a signoff CDC/RDC analysis tool.

Use these commands to validate or generate the selected build artifacts:

make check-soc-topology
make soc-topology
make check-user-extensions
make user-extensions
make check-clock-reset-domains

Generated files are written under build/<variant>/generated/soc_topology/ and build/<variant>/generated/user_extensions/; they must not be committed.