Add amba fabrics #31
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Add amba fabrics #31
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- In AXI4_Fabric, support read and write bursts.
- Added new AXI4_Deburster, placed in front of slave IPs mem
controller and slave boot rom, that converts burst requests from
fabric into individual non-burst requests into slave IPs.
- In MMU_Cache, changed cache-refill code to refill with a read-burst.
- Re-tested ISA tests: all ok.
Detail: in a write-burst of length N, the deburster was sending N AXI4 responses to the requestor; it should send only 1.
Was our mistake ('wid' used to be in AXI3 spec, was removed in AXI4 spec).
Tested on all RV64ACDFIMSU ISA tests: ok.
…ocations (no slave). Specifically: we were mistakenly popping an extra item from the awdata channel.
…ollows) The fabric uses an index (0..num_masters-1) to identify a master so it knows how to route responses. When num_masters=1, it's identification is a Bit#(0), on which equality tests are dicey. Fixed to assume a range (0..num_masters), so at least Bit #(1).
Using the modulus operator does not synthesise efficiently as wrap_boundary is not statically known to be a power of 2 without external knowledge of the AXI specification, putting it on a critical path with over -30ns WNS in the Connectal-based SSITH AWS SoC, and likely also AWSteria once FPGA builds are attempted. Instead, exploit the fact that the burst length is required to be a power of two, and use a bitmask to wrap the address within the aligned range.
Converts arbtitrary AXI4 read/write into aligned Load/Store; fully paramterized for AXI data bus and Load/Store data bus widths.
These are more economical (fewer FIFOs) than previous versions
This test attempts to recreate traffic patterns that were observed to cause data corruption in AWSteria.
…nges to addr and user fields in a master interface
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Discarding this PR (which I opened). Many things need fixing; will fix and submit a fresh PR. |
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Added Libraries/AMBA_Fabrics/ directory containing AXI4, AXI4_Lite and Adapter material, consolidating here from variants in a Bluespec-private repo and the Bluespec-public Flute repo.