Introduction

One of the traditional bottlenecks of 3D graphics hardware has been the rate at which pixels can be rendered into a frame buffer using conventional DRAM or VRAM. The 3D-RAM emerged from a complete rethinking of frame buffer technology and produces an order of magnitude increase in rendering performance.

**The factors responsible for the dramatic overall performance

improvement include:**

• New Memory Architecture
• 10-Mbits DRAM array supporting 1280 x 1024 x 8 frame buffer
• Four independent, interleaved DRAM banks
• 2048-bit SRAM Pixel Buffer as the cache between DRAM and ALU
• Built-in tile-oriented memory addressing for rendering and scan line- oriented memory addressing for video refresh
• 256-bit global bus connecting DRAM banks and Pixel Buffer
• Flexible dual Video Buffer supporting 85-Hz CRT refresh
• Write Mostly Interface
• On-chip ALU
• Four ROP units supporting 16 raster operations on byte data
• Four Blend units blending the old pixel value with new information
• On-chip hardware acceleration for all OpenGL blending modes(NEW)
• On-chip hardware acceleration for all OpenGL stencil modes (NEW)
• One 32-bit Match Comparator and one 32-bit Magnitude Comparator
• Concurrent operations of DRAM, Pixel Buffer, ALU and Video Buffer
• 32-bit synchronous high-bandwidth data bus interface with rendering controller
• Blending operations in both (8, 8, 8, 8) and (4, 4, 4, 4) color modes (NEW)
• One additional PASS_IN pin for flexible bit plane organization