RCP (chip)

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Casing of the Reality Co-Processor chip

RCP (Reality Co-Processor) is one of two main chips for the Nintendo 64 (the other being a derivative of the MIPS R4200, the R4300i). It was developed by Silicon Graphics for Nintendo.

The RCP consists of two main components: the RSP (Reality Signal Processor) and the RDP (Reality Display Processor).

Reality Signal Processor[edit]

The RSP is a vector processor designed for high performance 3D calculations. It handles some audio and most video pre-processing of the Nintendo 64 and can perform very well in operations such as: real-time edge anti-aliasing, high frame-rate on complex images, automatic load-management, advanced texture mapping, real-time depth buffering, etc. The RSP has access to 4 KB of DMEM (Data Memory) and executes instructions contained within its 4 KB of IMEM (Instruction Memory), allowing 1024 instructions to be stored at any given time. These instructions are collectively referred to as microcode. Microcode may be designed to perform specific tasks, such as lighting calculations, or RDP display list processing for example. The RSP is able to efficiently transfer data to and from main memory and DMEM/IMEM using DMA.

Reality Display Processor[edit]

The RDP is programmed by use of display lists. A display list contains a series of commands (each of variable size) which give instructions to the RDP and control its operating state. The RDP is capable of rendering shaded, textured and depth buffered geometry to an arbitrary frame buffer in main memory.[1] The RDP contains 4 KB of on-chip TMEM (texture memory) in which the RDP can reference up to eight textures (so called, "tiles") at any given time. The size of the available texture memory may be reduced further if using texture lookup tables (TLUT), since the high 2 KB will be used to store the lookup tables. This texture memory limitation is widely considered a design flaw of the RDP.

History[edit]

During the development of GoldenEye 007, a weapon (RCP-90) was included as an in-joke amongst the developers.

References[edit]