Sega 32X/Technical specifications
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Technical specifications for the Sega 32X.
Contents
The following are upgrades over the Sega Mega Drive technical specifications.
- See Sega Mega Drive technical specifications for details of the base Mega Drive hardware
CPU
- Clock speed: 23.01136 MHz (NTSC), 22.801467 MHz (PAL)[1]
- Clock cycles: 46.022721 MHz (NTSC, 23.01136 MHz per SH-2), 45.602934 MHz (PAL, 22.801467 MHz per SH-2)
- 2x CPU cores: 32‑bit RISC instructions/registers, up to 4 instructions/cycle (2 instructions/cycle per SH-2),[2] 1.3 MIPS per MHz,[3] 59.829537 MIPS (NTSC, 29.914768 MIPS per SH-2), 59.283814 MIPS (PAL, 29.641907 MIPS per SH-2)
- 4x internal fixed‑point math processors:[4] 2x MULT multiplier DSP,[5][6][7] 2x DIVU division units,[5][6] parallel processing[8]
- CPU co-processors: Overlay/Underlay processors
- Mega Drive CPU:
- Motorola M68000 — 7.670453 MHz (NTSC), 7.600489 MHz (PAL),[1] 16/32-bit instructions, 32-bit internal data bus, 16-bit external data bus, 1.342329 MIPS (NTSC), 1.330085 MIPS (PAL)
- Zilog Z80 — 3.579545 MHz (NTSC), 3.546894 MHz (PAL), 8/16-bit instructions, 8-bit data bus, 0.519034 MIPS (NTSC), 0.514299 MIPS (PAL)
- Sega CD CPU: Motorola M68000 — 12.5 MHz, 2.1875 MIPS
Graphics
- Data bus width: 32-bit (16-bit per framebuffer)
- Word length: 16-bit
- Features: 3D polygon graphics, Gouraud shading, texture mapping, more sprites, quicker animation[14]
- Color palette: 32,768 colors[15]
- Double-buffered framebuffer with three modes:[16]
- 8bpp "packed pixel" mode: 256 simultaneous colors on screen; each pixel is an index into CRAM (can use full screen)
- 16bpp "run length" mode: 256 simultaneous colors on screen; each pixel is both a number of pixels to display and the index of CRAM (limits screen size)
- 16bpp "direct color" mode: 32,768 simultaneous colors on screen; each pixel is the color value (limits screen size)
- VRAM: 256 KB, split into two 128 KB segments for each framebuffer. A priority system allows partial overlaying/underlaying of Mega Drive/Mega-CD graphics.
- Sprites, polygons and textures accessed from 256 KB main SDRAM and 4–8 MB ROM cartridge.
- Overscan: 450×262 (NTSC), 450×313 (PAL)[19]
- Refresh rate: 60 Hz (NTSC), 50 Hz (PAL)
- Maximum frame rate: 60 FPS (NTSC), 50 FPS (PAL)
- 3D polygon geometry calculations:[fn 3]
- Polygon transformations: Up to 260,000 polygons/sec (130,000 polygons/sec per CPU)[fn 4]
- Lighting calculations: Up to 230,000 polygons/sec (flat),[fn 5] 180,000 polygons/sec (Gouraud)[fn 6]
- Theoretical 3D polygon rendering performance, with both CPUs dedicated to graphics:
- Flat shading: Up to 160,000 polygons/sec[fn 7]
- Gouraud shading: Up to 100,000 polygons/sec[fn 8]
- Texture mapping: Up to 50,000 polygons/sec[32][fn 9]
- Texture Gouraud shading: Up to 40,000 polygons/sec[fn 10]
- Practical 3D polygon rendering performance, with one CPU dedicated to graphics:
- Flat shading: Up to 80,000 polygons/sec
- Gouraud shading: Up to 50,000 polygons/sec
- Texture mapping: Up to 25,000 polygons/sec
- Texture Gouraud shading: Up to 20,000 polygons/sec
- Colors per sprite/tile: 128 (8bpp), 256 (8bpp), 8192 (16bpp), 32,768 (16bpp)
- Tile size: 8×8 texels, 64 bytes (8bpp), 128 bytes (16bpp)
- Sprite sizes: 8×8 to 320×240 texels, 64 bytes to 150 KB
- Maximum sprites/tiles per frame: 3800 sprites/tiles (8bpp, 8×8, 237.5 KB), 1900 sprites/tiles (16bpp, 8×8, 237.5 KB)
- Maximum sprites/tiles per scanline: 1463 texels, 182 sprites/tiles (8×8)
Overlay/Underlay
- Overlay/Underlay graphics processors:
- Overlay/Underlay Mega Drive VDP planes: 512–1536 color palette, 61–512 colors on screen
- Sprite plane: 80 sprites/frame, 8×8 to 32×32 pixels/sprite, 16 colors/sprite, maximum 1280 sprite tiles/frame
- Background planes: 2 tiled scrolling background layers, 8×8 pixels/tile, 16 colors/tile, 320×224 tilemaps, maximum 1808 tiles/frame
- Fillrate: 6.934358 MPixels/s (read), 6.41376 MPixels/s (write), 6.934358–36.325644 MPixels/s (effective tile fillrate)
- Overlay/Underlay Sega CD ASIC planes: Enhanced Mega Drive VDP planes, enhanced FMV plane
- Sprite/Tile planes: 128–1536 colors on screen, sprite/tile scaling and rotation
- FMV plane: Full motion video, 32,768 colors on screen
- Fillrate: 6.934358 MPixels/s (read/write), 6.934358–36.325644 MPixels/s (effective tile fillrate)
Audio
- Stereo PWM (Pulse Wave Modulation) mixing with Mega Drive sound; additional 2 channels (12 channels in total)
- 11-bit PWM, stereo PCM output,[15] surround sound
Memory
- System RAM: 648.5–1368.5 KB total, 512 KB (4 MBit) additional RAM to Mega Drive or Sega CD memory[14]
Bandwidth
- System RAM bandwidth: 118.749992 MB/s (NTSC), 118.330206 MB/s (PAL), 3 data buses, 48-bit data bus width[13][21]
- Game ROM: 13.333333 MB/s (16-bit, 6.666666 MHz, 150 ns) to 28.571428 MB/s (16-bit, 14.285714 MHz, 70 ns)
- Non-volatile SRAM: 6.666666 MB/s (6.666666 MHz, 150 ns) to 14.285714 MB/s (14.285714 MHz, 70 ns)
- Internal processor cache bandwidth:
- SH-2: 184.09088 MB/s (92.04544 MB/s per SH-2, 32-bit per SH-2)
- 32X VDP: 92.04544 MB/s (32-bit, 23.01136 MHz), including 46.02272 MB/s (16-bit, 23.01136 MHz) color palette RAM[43]
Storage
- Cartridge: Compatible with all Mega Drive models, JVC Wondermega can store save game/score information.
- CD-ROM: If you have a Sega Mega-CD; speed same as Sega Mega-CD compatible with audio CD, CD&G, SegaCD and JVC WonderMega
Input/Output
- I/O: Same as Mega Drive; 32X upgradable; can upgrade the 32X
BIOS
BIOS Version | Machine | Download |
---|---|---|
68000 | 32X (US) | 68000 (info) (292 bytes) |
SH-2 Master | 32X (US) | SH-2 Master (info) (1 kB) |
SH-2 Slave | 32X (US) | SH-2 Slave (info) (427 bytes) |
Notes
- ↑ [1 operation per cycle[9] 1 operation per cycle[9]]
- ↑ [39 cycles per divide[10] 39 cycles per divide[10]]
- ↑ [46,022,720 DSP operations/sec, 1,180,069 DIVU divides/sec 46,022,720 DSP operations/sec, 1,180,069 DIVU divides/sec]
- ↑ [96 adds/multiplies and 9 divides per polygon:[27]
- 131,118 polygons/sec: 12,587,328 DSP operations, 1,180,069 DIVU divides
- 134,397 polygons/sec: 32,255,280 SH-2 cycles (96 adds/multiplies, 144 divide cycles)[10]
- 131,118 polygons/sec: 12,587,328 DSP operations, 1,180,069 DIVU divides
- 134,397 polygons/sec: 32,255,280 SH-2 cycles (96 adds/multiplies, 144 divide cycles)[10]]
- ↑ [128 adds/multiplies and 9 divides per polygon:[27]
- 131,118 polygons/sec: 16,783,104 DSP operations, 1,180,069 DIVU divides
- 103,160 polygons/sec: 28,059,520 SH-2 cycles (128 adds/multiplies, 144 divide cycles)
- 131,118 polygons/sec: 16,783,104 DSP operations, 1,180,069 DIVU divides
- 103,160 polygons/sec: 28,059,520 SH-2 cycles (128 adds/multiplies, 144 divide cycles)]
- ↑ [192 adds/multiplies and 9 divides per polygon:[27]
- 131,118 polygons/sec: 25,174,656 SH-2 DSP operations, 1,180,069 DIVU divides
- 58,535 polygons/sec: 19,667,760 SH-2 cycles (192 adds/multiplies, 144 divide cycles)
- 131,118 polygons/sec: 25,174,656 SH-2 DSP operations, 1,180,069 DIVU divides
- 58,535 polygons/sec: 19,667,760 SH-2 cycles (192 adds/multiplies, 144 divide cycles)]
- ↑ [46,022,720 SH-2 cycles/ops per sec (23.01136 MHz per SH-2), 1,180,069 DIVU divides/sec, 23.01136 MHz 32X VDP
- SH-2: 215 cycles (128 geometry adds/multiplies, 30 SDRAM cycles for 40 bytes,[28] 30 raster ops,[29][30] 27 cycles 32X VDP command)[23] and 9 divides per polygon, 1 add per pixel,[31] 247 cycles and 9 divides per 32-pixel polygon:
- 131,118 polygons/sec: 32,386,146 SH-2 cycles, 1,180,069 DIVU divides
- 31,858 polygons/sec: 12,456,478 SH-2 cycles (247 cycles, 144 divide cycles)
- 32X VDP: 7 cycles/poly, 3 cycles/pixel (16bpp),[23][24] 1.5 cycles/pixel (8bpp),[18] 103 cycles per 32-pixel 16bpp polygon, 55 cycles per 32-pixel 8bpp polygon
- SH-2: 215 cycles (128 geometry adds/multiplies, 30 SDRAM cycles for 40 bytes,[28] 30 raster ops,[29][30] 27 cycles 32X VDP command)[23] and 9 divides per polygon, 1 add per pixel,[31] 247 cycles and 9 divides per 32-pixel polygon:
- 131,118 polygons/sec: 32,386,146 SH-2 cycles, 1,180,069 DIVU divides
- 31,858 polygons/sec: 12,456,478 SH-2 cycles (247 cycles, 144 divide cycles)
- ↑ [252 cycles (192 geometry adds/multiplies,[27] 30 SDRAM cycles, 30 raster ops) and 9 divides per polygon, 3 operations/scanline per polygon,[30][21] 264 cycles and 9 divides per 4-scanline polygon
- 16bpp: 3 cycles per pixel, 369 SH-2 cycles and 9 DIVU divides per 32-pixel polygon
- 16bpp: 3 cycles per pixel, 369 SH-2 cycles and 9 DIVU divides per 32-pixel polygon]
- ↑ [Texture mapping:
- Flat shading: 188 SH-2 cycles (128 geometry adds/multiplies, 30 SDRAM cycles for 40 bytes,[28] 30 raster ops)[29][30] and 9 divides per polygon, 1 add per pixel,[31] 220 SH-2 cycles and 9 divides per 32-pixel polygon
- Texture mapping: 132 SH-2 cycles and 41 divides per 32-texel polygon
- 132 SH-2 cycles per 32-texel texture: 2 block moves, 2 cycles per texel (2 bytes per texel), 2 cycles access
- 41 divides per 32-texel polygon, 9 divides per polygon, 32 divides per 32-texel polygon (1 divide per texel)[33]
- Texture mapping: 352 SH-2 cycles and 50 divides per 32-texel polygon
- 23,601 polygons/sec: 9,487,602 SH-2 cycles, 1,180,069 DIVU divides
- 31,714 polygons/sec: 36,535,118 SH-2 cycles (1152 cycles per polygon) Texture mapping:
- Flat shading: 188 SH-2 cycles (128 geometry adds/multiplies, 30 SDRAM cycles for 40 bytes,[28] 30 raster ops)[29][30] and 9 divides per polygon, 1 add per pixel,[31] 220 SH-2 cycles and 9 divides per 32-pixel polygon
- Texture mapping: 132 SH-2 cycles and 41 divides per 32-texel polygon
- 132 SH-2 cycles per 32-texel texture: 2 block moves, 2 cycles per texel (2 bytes per texel), 2 cycles access
- 41 divides per 32-texel polygon, 9 divides per polygon, 32 divides per 32-texel polygon (1 divide per texel)[33]
- Texture mapping: 352 SH-2 cycles and 50 divides per 32-texel polygon
- 23,601 polygons/sec: 9,487,602 SH-2 cycles, 1,180,069 DIVU divides
- 31,714 polygons/sec: 36,535,118 SH-2 cycles (1152 cycles per polygon)]
- ↑ [Texture Gouraud shading:
- Gouraud shading: 369 SH-2 cycles and 9 divides per 32-pixel polygon
- Texture mapping: 132 SH-2 cycles and 41 divides per 32-texel polygon
- Texture Gouraud shading: 501 SH-2 cycles and 50 divides per 32-texel polygon
- 23,601 polygons/sec: 11,824,101 SH-2 cycles, 1,180,069 DIVU divides
- 25,379 polygons/sec: 33,018,079 SH-2 cycles (1301 cycles per polygon) Texture Gouraud shading:
- Gouraud shading: 369 SH-2 cycles and 9 divides per 32-pixel polygon
- Texture mapping: 132 SH-2 cycles and 41 divides per 32-texel polygon
- Texture Gouraud shading: 501 SH-2 cycles and 50 divides per 32-texel polygon
- 23,601 polygons/sec: 11,824,101 SH-2 cycles, 1,180,069 DIVU divides
- 25,379 polygons/sec: 33,018,079 SH-2 cycles (1301 cycles per polygon)]
References
- ↑ 1.0 1.1 1.2 1.3 File:32XUSHardwareManual.pdf, page 54
- ↑ File:Hitachi SuperH Programming Manual.pdf, page 390
- ↑ File:SH-2A.pdf, page 2
- ↑ File:Sega Service Manual - Sega Saturn (PAL) - 013-1 - June 1995.pdf
- ↑ 5.0 5.1 5.2 File:SH7604 Hardware Manual.pdf, page 3
- ↑ 6.0 6.1 File:SH7604 Hardware Manual.pdf, page 22
- ↑ File:ST-103-R1-040194.pdf, page 23
- ↑ 8.0 8.1 File:SH7604 Hardware Manual.pdf, page 303
- ↑ File:Hitachi SuperH Programming Manual.pdf, page 31
- ↑ 10.0 10.1 File:Hitachi SuperH Programming Manual.pdf, page 155
- ↑ File:SH7604 Hardware Manual.pdf, page 219
- ↑ File:ST-103-R1-040194.pdf
- ↑ 13.0 13.1 File:Genesis32XUSManual.pdf, page 7
- ↑ 14.0 14.1 14.2 File:Genesis32XUSOverview.pdf
- ↑ 15.0 15.1 File:32XUSHardwareManual.pdf
- ↑ 16.0 16.1 File:Genesis32XUSOverview.pdf, page 7
- ↑ File:32XUSHardwareManual.pdf, page 49
- ↑ 18.0 18.1 18.2 File:32XUSHardwareManual.pdf, page 50
- ↑ 19.0 19.1 File:32XUSHardwareManual.pdf, page 55
- ↑ 20.0 20.1 File:TC511664B datasheet.pdf
- ↑ 21.0 21.1 21.2 21.3 21.4 21.5 File:32XUSHardwareManual.pdf, page 76
- ↑ 22.0 22.1 22.2 File:Genesis32XUSOverview.pdf, page 9
- ↑ 23.0 23.1 23.2 File:32XUSHardwareManual.pdf, page 53
- ↑ 24.0 24.1 File:Genesis32XUSOverview.pdf, page 51
- ↑ File:Genesis32XUSOverview.pdf, page 53
- ↑ File:32XUSHardwareManual.pdf, page 42
- ↑ 27.0 27.1 27.2 27.3 Design of Digital Systems and Devices (pages 95-97)
- ↑ 28.0 28.1 File:32XUSHardwareManual.pdf, page 77
- ↑ 29.0 29.1 Algorithms for Parallel Polygon Rendering (pages 33-36)
- ↑ 30.0 30.1 30.2 Transformation Of Rendering Algorithms For Hardware Implementation (page 53)
- ↑ 31.0 31.1 Algorithms for Parallel Polygon Rendering (page 35)
- ↑ Service Games: The Rise and Fall of SEGA, page 154
- ↑ State of the Art in Computer Graphics: Visualization and Modeling (page 110)
- ↑ File:32XUSHardwareManual.pdf, page 51
- ↑ Sprite engine for the Sega 32X
- ↑ 36.0 36.1 File:Genesis32XUSManual.pdf
- ↑ File:32XUSHardwareManual.pdf, page 41
- ↑ File:32XUSHardwareManual, page 13
- ↑ 39.0 39.1 Dr. DevSter's Guide to The Sega 32X
- ↑ File:Genesis32XUSManual.pdf, page 17
- ↑ File:UPD4504161 datasheet.pdf
- ↑ File:Genesis32XUSManual.pdf, page 22
- ↑ File:Genesis32XUSManual, page 7
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