GPU

Overview

32-bit Sony GPU (designed by Toshiba)

• Handles display of graphics, control of framebuffer, and drawing of polygons and textures
• Handles 2D graphics processing, in a similar manner to the 3D engine
• RAM:
  • 1 MB VRAM (later models used SGRAM) for framebuffer
  • 2 KB texture cache (132 MB/s memory bus bandwidth, 32-bit wide)
  • 64 bytes FIFO buffer
• Features:
  • Adjustable framebuffer (1024×512)
  • Emulation of simultaneous backgrounds (to simulate parallax scrolling)
  • Mask bit
  • Texture window
  • Dithering
  • Clipping
  • Alpha blending (4 per-texel alpha blending modes)
  • Fog
  • Framebuffer effects
  • Transparency effects
  • Render to texture
  • Offscreen rendering
  • Multipass rendering
  • Flat or Gouraud shading and texture mapping
  • No line restriction
  • Colored light sourcing
• Resolutions:
  • Progressive: 256×224 to 640×240 pixels
  • Interlaced: 256×448 to 640×480 pixels
• Colors:
  • Maximum color depth of 16,777,216 colors (24-bit true color)
  • 57,344 (256×224) to 153,600 (640×240) colors on screen
  • Unlimited color lookup tables (CLUTs)
  • 32 levels of transparency
  • All calculations are performed to 24 bit accuracy
• Texture mapping color mode:
  • Mode 4: 4-bit CLUT (16 colors)
  • Mode 8: 8-bit CLUT (256 colors)
  • Mode 15: 15-bit direct (32,768 colors)
  • Mode 24: 24-bit (16,777,216 colors)
• Sprite engine:
  • 1024×512 framebuffer, 8×8 and 16×16 sprite sizes, bitmap objects
  • Up to 4,000 sprites on screen (at 8×8 sprite size), scaling and rotation
  • 256×256 maximum sprite size
• Special sprite effects:
  • Rotation
  • Scaling up/down
  • Warping
  • Transparency
  • Fading
  • Priority
  • Vertical and horizontal line scroll

Revisions

CXD8514

• CXD8514Q
  • Found on PU-7 and on early PU-8 (until -12)
  • First revision to be sold to consumers

CXD8561

• CXD8561Q
  • Found on some PU-8 (-21 and onwards)
  • This version and all versions onwards use SGRAM for video memory
  • Supports 8-bit shading and full-screen dithering, thus less color banding in games
  • Some performance improvements
• CXD8561AQ
  • Found on some PU-20 and some PU-22
• CXD8561BQ
  • Found on some PU-16, PU-18 and PU-20
  • Die size: 54 mm²
• CXD8561CQ
  • Found on some PU-22, PU-23 and PM-41 (until -51)
  • Die size: 54 mm² (thus not shrunk compared to the previous revision)

CXD9500

• CXD9500Q
  • Found on some PM-41 (-61 onwards)
  • SGRAM integrated into GPU