/hsb-ip-packetizer

Packetizer HOLOLINK_def.svh Fields

Use this reference to choose or explain the packetizer-local fields in HOLOLINK_def.svh.

This file documents known HSB IP rev 16'h2604 and backward-compatible rev 16'h2603. If live HSB IP source is available, verify the HOLOLINK_top.sv mapping into packetizer_top and the packetizer RTL constraints against that source before emitting enabled packetizer fields. Live source wins when it disagrees with this reference.

Field Table

The listed values are examples, not a closed legal set. For enabled packetizers, screen proposed values against the RTL-derived constraints below before suggesting them.

Required Context

Know these before choosing enabled packetizer values:

• SENSOR_RX_IF_INST: number of Sensor RX interfaces; all packetizer arrays are sized to it.
• SIF_RX_WIDTH[i]: the input width for packetizer instance i; HOLOLINK_top passes this as DIN_WIDTH.
• The desired data manipulation per interface: pass-through, data rearrangement, split into virtual ports, replicate/duplicate, or another runtime-controlled pattern.

Do not choose packetizer values just because they appear in an archetype. Ask what the data needs to do, derive the full field set from that description, then explain the result. Do not make the user approve each packetizer field separately.

Array Rules

• SIF_RX_PACKETIZER_EN[] length must equal SENSOR_RX_IF_INST.
• If any enable entry is 1, all four peer arrays must be present and length-matched.
• If enable entry i is 0, peer entries at index i are ignored by the IP.
• If every enable entry is 0, the peer arrays are unnecessary for the packetizer decision.

Existing def skill validation mirrors these rules:

• HD-E126: enable element is not 0 or 1.
• HD-E302: enable array length mismatch.
• HD-E303 through HD-E306: peer array length mismatch when any packetizer is enabled.
• HD-W305: packetizer enabled but a peer array is missing.
• HD-I001: peer array value exists for a disabled packetizer and is a don't-care.

Disabled Entries

For a disabled entry inside a mixed array, use the RTL bypass constants as placeholders:

HOLOLINK_top substitutes these same values when SIF_RX_PACKETIZER_EN[i] is 0: PACK_SORT_RESOLUTION=2, PACK_VP_COUNT=1, PACK_VP_SIZE=32, and PACK_NUM_CYCLES=1 (top/HOLOLINK_top.sv:1356-1362).

RTL-Derived Constraints

Treat these as guardrails before recommending an enabled-packetizer value:

• SIF_RX_PACKETIZER_EN[i] must be 0 or 1.
• SIF_RX_VP_COUNT[i] must be positive. HOLOLINK_top protects only the local SIF_VP_INST width when the value is zero, but still passes PACK_VP_COUNT=SIF_RX_VP_COUNT[i] into packetizer_top (top/HOLOLINK_top.sv:1356-1382).
• SIF_RX_SORT_RESOLUTION[i] must be positive and should divide SIF_RX_WIDTH[i]. The packetizer computes widths from DIN_WIDTH/SORT_RESOLUTION and indexes odd-even lookup tables from $clog2(DIN_WIDTH)-$clog2(SORT_RESOLUTION) (packetizer/packetizer.sv:69-85, :213-224).
• Prefer power-of-two SIF_RX_SORT_RESOLUTION[i] values. The odd-even network is built around powers of two (packetizer/odd_even_gen.sv:30-60).
• SIF_RX_VP_SIZE[i] is used as a bit width. It appears in vector declarations, shifts, FIFO input width, and DIN_WIDTH/VP_SIZE control sizing (packetizer/virtual_port.sv:18-30, :55-99, :153-170, :210-212).
• For HOLOLINK_top's current packetizer instantiation, DYNAMIC_VP and MIXED_VP_SIZE are forced to 0 (top/HOLOLINK_top.sv:1360-1361, :1379-1380). Prefer a positive power-of-two SIF_RX_VP_SIZE[i] that is no greater than and divides SIF_RX_WIDTH[i].
• SIF_RX_NUM_CYCLES[i] must be positive. The core declares arrays sized by NUM_CYCLES and uses $clog2(NUM_CYCLES+1) (packetizer/packetizer.sv:77-85, :140-179).
• If SIF_RX_SORT_RESOLUTION[i] == SIF_RX_WIDTH[i], packetizer_top disables the sort network internally (packetizer/packetizer_top.sv:393-400).

Output Formatting

For standalone SVH, emit only packetizer localparams. Put the block under the existing SENSOR_RX_IF_INST section of HOLOLINK_def.svh. This section is the canonical source for standalone SVH output examples; references/handoff-contract.md owns the packetizer_profile_overlay YAML examples for hsb-ip-def.

All disabled:

localparam integer SIF_RX_PACKETIZER_EN    [`SENSOR_RX_IF_INST-1:0] = '{default:0};

Mixed enabled/disabled:

localparam integer SIF_RX_PACKETIZER_EN    [`SENSOR_RX_IF_INST-1:0] = {1, 0};
localparam integer SIF_RX_VP_COUNT         [`SENSOR_RX_IF_INST-1:0] = {4, 1};
localparam integer SIF_RX_SORT_RESOLUTION  [`SENSOR_RX_IF_INST-1:0] = {16, 2};
localparam integer SIF_RX_VP_SIZE          [`SENSOR_RX_IF_INST-1:0] = {128, 32};
localparam integer SIF_RX_NUM_CYCLES       [`SENSOR_RX_IF_INST-1:0] = {1, 1};

Uniform enabled:

localparam integer SIF_RX_PACKETIZER_EN    [`SENSOR_RX_IF_INST-1:0] = '{default:1};
localparam integer SIF_RX_VP_COUNT         [`SENSOR_RX_IF_INST-1:0] = '{default:4};
localparam integer SIF_RX_SORT_RESOLUTION  [`SENSOR_RX_IF_INST-1:0] = '{default:16};
localparam integer SIF_RX_VP_SIZE          [`SENSOR_RX_IF_INST-1:0] = '{default:128};
localparam integer SIF_RX_NUM_CYCLES       [`SENSOR_RX_IF_INST-1:0] = '{default:1};