step i/u / 0xD3

Opcode map

Property	Definition
OP	0xD3
Operands	D,S2,S1
Operation	Even updates R=G=B=intensity; odd updates U and UDir. Also adds operands into RISC destination. Illegal when DrawCtl[3:0]=11. Other color/coordinate formats 16I.16F.
Timing	Count → draw hazard 1; XShadow → parallel draw hazard 1; triangle shadow destination → step hazard 2

Instruction hazards · Instruction formats

Source: Technical Spec, p.12