Vector Processor Unit 0 (VPU0/VU0/COP1)

Figure 3.4. Block diagram of the Playstation 2 - Vector Processing Units

Vector Unit 0 (VU0) is one of the EE co-processors and is used primarily for geometry processing. Both vector units are micro-programmable processors with their own instruction and data space.

The main features of VU0 include:

VU0 can run in two modes; macro-mode and micro-mode. In macro-mode, the EE can call VU0 instructions directly and fetch the results. In micro-mode, a small vector unit micro-program is uploaded by the EE and subsequently executed. An example would be the VU0 processing physics effects on particles before they are sent to VU1 for the rendering phase. After the micro-program has run, the EE can then retrieve the results of the micro-program.