C.B.DIMI

assembly

[
  "C.B.DIMI imm8, ->LB0",
  "C.B.DIMI imm8, ->LB1",
  "C.B.DIMI imm8, ->LB2"
]

block

[]

catalog_indices

[
  53
]

catalog_records

[
  {
    "asm": "C.B.DIMI imm, ->{LB0, LB1, LB2}",
    "constraints": [
      {
        "field": "LoopNest",
        "operator": "not-equal",
        "value": 3
      }
    ],
    "encoding": [
      {
        "index": 0,
        "mask": "0x003f",
        "match": "0x003c",
        "width_bits": 16
      }
    ],
    "encoding_kind": "C16",
    "fields": [
      {
        "name": "LoopNest",
        "pieces": [
          {
            "instruction_lsb": 14,
            "value_lsb": 0,
            "width": 2
          }
        ],
        "signedness": "encoding-defined",
        "width": 2
      },
      {
        "name": "imm8",
        "pieces": [
          {
            "instruction_lsb": 6,
            "value_lsb": 0,
            "width": 8
          }
        ],
        "signedness": "encoding-defined",
        "width": 8
      }
    ],
    "form_id": "c_b_dimi_16_3f1b113c76ce",
    "length_bits": 16,
    "mnemonic": "C.B.DIMI",
    "semantic_family": "CMD",
    "semantic_group": "Bundle Dimension",
    "semantic_handler": "SetBundleDimension",
    "semantic_summary": "Zero-extends imm8 and writes one selected bundle-local LB exactly once.",
    "status": "accepted"
  }
]

classification

[
  "attributes"
]

contract

{
  "block_composition": [
    "Header command after BSTART and before the first body instruction. C.B.DIMI and B.DIM share one write-once presence bit for each of LB0, LB1, and LB2."
  ],
  "canonical_assembly": [
    "C.B.DIMI imm8, ->LB0",
    "C.B.DIMI imm8, ->LB1",
    "C.B.DIMI imm8, ->LB2"
  ],
  "defaults": [
    "LoopNest 0, 1, and 2 select LB0, LB1, and LB2. imm8 is always present; encoded zero writes numeric zero and is not omission."
  ],
  "encoding_class": "standalone-encoded",
  "examples": [
    "C.B.DIMI 0, ->LB0",
    "C.B.DIMI 255, ->LB2"
  ],
  "exceptions": [
    "LoopNest code 3 raises Fault_IllegalInstruction before changing TPC or bundle state.",
    "Execution outside an active block header or a second write to the same LB across C.B.DIMI and B.DIM raises Fault_BundleControl before changing the first value."
  ],
  "field_contracts": {},
  "field_zero_meanings": {
    "LoopNest": "Code zero selects LB0.",
    "imm8": "Encoded zero writes numeric zero to the selected LB."
  },
  "legality": [
    "LoopNest codes 0..2 are assigned to LB0..LB2; code 3 is reserved.",
    "imm8 accepts every unsigned value 0..255 and is zero-extended to the bundle dimension word.",
    "Each selected LB is write-once for one block across full and compressed dimension commands."
  ],
  "memory_effects": [
    "none"
  ],
  "operands": [
    {
      "field": "LoopNest",
      "role": "encoded LB0, LB1, or LB2 selector"
    },
    {
      "field": "imm8",
      "role": "unsigned eight-bit bundle-local dimension value"
    }
  ],
  "ordering": [
    "Placement and duplicate checks precede the LB update. A successful update sets the presence bit and value together, then command dispatch advances TPC by two bytes."
  ],
  "standalone_opcode": true,
  "state_effects": [
    "Write ZeroExtend(imm8) to the selected raw LB and set its presence bit.",
    "LB meaning is selected by the completed operation schema; C.B.DIMI assigns no universal row, column, M, N, or K role."
  ]
}

depends_on

[
  "PTO-BLOCK-MODEL-SCHEMA-DIMENSIONS"
]

id

PTO-BLOCK-C-B-DIMI

mnemonic

C.B.DIMI

summary

Writes one selected bundle-local LB from a zero-extended eight-bit immediate exactly once.

surface

block

{
  "classification": [
    "attributes"
  ],
  "documentation": "docs/block/attributes/C.B.DIMI.md",
  "id": "PTO-BLOCK-C-B-DIMI",
  "instruction_contract": {
    "artifact": "spec/evidence/instruction-contract-closure.json",
    "mnemonic": "C.B.DIMI",
    "ndf_clause": "PTO-INST-BLOCK-C-B-DIMI"
  },
  "mnemonic": "C.B.DIMI",
  "readiness_subjects": [
    "ADR-0032",
    "ADR-0052",
    "ADR-0059"
  ],
  "semantic_tests": [
    "PTO-AVS-BLOCK-C-B-DIMI-DUP-001",
    "PTO-AVS-BLOCK-C-B-DIMI-PLACE-001",
    "PTO-AVS-BLOCK-C-B-DIMI-RSVD-001",
    "PTO-AVS-BLOCK-C-B-DIMI-VALUES-001"
  ],
  "source": "asl/block/attributes/C.B.DIMI.asl",
  "surface": "block",
  "tests": [
    "PTO-AVS-BLOCK-C-B-DIMI-DECODE-001",
    "PTO-AVS-BLOCK-C-B-DIMI-DUP-001",
    "PTO-AVS-BLOCK-C-B-DIMI-PLACE-001",
    "PTO-AVS-BLOCK-C-B-DIMI-RSVD-001",
    "PTO-AVS-BLOCK-C-B-DIMI-VALUES-001"
  ]
}