Node Editor

The Data Flow tab hosts a Blender-inspired block-diagram canvas where pccx-v002 topology nodes can be dragged, wired, and tweaked interactively.

pccx-lab Node Editor with the default NPU dataflow and minimap

Layout

Area

Role

Left palette

Categorised, collapsible, searchable node library (Input / Memory / Compute / Output)

Canvas

Infinite pan/zoom, minimap overlay, zoom controls

Quick-add

Shift+A floating popover anchored at the cursor — same convention as Blender

Node catalogue

Thirteen node types ship in the default build; five are pccx-v002 specific and mirror the actual KV260 accelerator topology.

Input

  • Host CPU — AXI-Lite master, configurable PCIe / CXL interface.

Memory

  • DRAM — off-chip: LPDDR5 / HBM2E / DDR5 / GDDR6X with tunable BW + capacity

  • AXI Fabric — 128-bit interconnect with burst length, overhead, and port count

  • BRAM L1 — on-chip scratchpad, per-port BW and bank count

  • URAM L2 (v002) — 64 URAMs, 1.75 MB, 2-cycle read

  • HP Buffer (v002) — 4-port HP AXI pre-fetch FIFO, separate upper / lower weight channels

  • fmap Cache (v002) — 27 b × 2048 entries, 32-lane broadcast

Compute

  • GEMM MAC Array (v002) — 32 × 32 W4A8 systolic, 65.5 TOPS at 1 GHz

  • GEMV Engine (v002) — 4 lanes × 32 MAC, 5-stage pipeline

  • CVO SFU (v002) — single instance, CORDIC + LUT for exp / sqrt / GELU / sin / cos / softmax

  • Accumulator — register file + adder tree

Output

  • Post-Proc — activation / normaliser / quantiser / softmax toggle

  • Write-back DMA — 1 / 2 / 4 / 8-channel egress

Keyboard shortcuts

Shortcut

Action

Shift+A

Open quick-add menu at cursor

Esc

Close quick-add menu

Delete / Backspace

Remove selected node(s) / edge(s)

Scroll

Zoom in / out

Drag canvas

Pan

Drag palette entry

Spawn at drop position

Double-click entry

Spawn at canvas centre

Ctrl-Scroll / pinch-zoom also work. The palette collapse state is per-category, not per-session — refresh keeps it expanded.

Typed sockets (colour legend)

Each node exposes one or more coloured handles:

Colour

Data type

#94a3b8 grey

command / control

#60a5fa blue

AXI read / stream

#818cf8 indigo

AXI fabric / interconnect

#22d3ee cyan

fmap / broadcast channel

#34d399 green

tile A / primary compute stream

#a78bfa violet

tile B / MAC partial sum

#f59e0b amber

accumulator / stall

#fb923c orange

post-proc output

#f472b6 pink

DMA egress / write-back

#e879f9 fuchsia

SFU / non-linear

#f87171 red

HP buffer input

#14b8a6 teal

URAM read / L2

#eab308 yellow

fmap cache broadcast

The default wiring mirrors the pccx v002 dataflow (Host → AXI → BRAM → MAC → Accumulator → Post-Proc → Write-back), so the canvas is already a valid starting point for experimentation.

Roadmap

  • Frame / group (nested sub-graphs, Blender style).

  • Typed socket validation — reject mismatched drops with a visible tooltip.

  • SVG / PNG export of the current canvas.

  • Animated data-flow playback synced to the loaded .pccx.