search

grayresearch / CX

Proposed RISC-V Composable Custom Extensions Specification
Apache License 2.0
66 stars 12 forks source link

add CX CSRs: Issues #27, #33 #36

Closed grayresearch closed 5 months ago

grayresearch commented 5 months ago
  1. Add per CX custom address CSRs (CX CSRs).
  2. Add CX CSRs to CX multiplexing.
  3. Add CX CSRs to CXU-LI.
  4. Modify CXU-LI req_func / FUNC_ID to encode both CF instructions and custom CSR access instructions.
  5. Rename mcx_selector.cte to mcx_selector.cxe.
  6. Resize mcx_selector.version from 4-bits to 3-bits.
  7. Change cx_imm encoding to use uniform I-type 12b immediate (a la addi and csrrw).
  8. Remove -Zicx language from spec.
  9. Add a requirement that cx_status updates are precise.
  10. Add History entry for CX CSR changes.

Resolves Issues #27, #33.