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CGRAM: Difference between revisions
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'''CGRAM''' (Color Generator<sup>[2]</sup> RAM) is where palettes are stored for [[indirect color]]. The SNES uses 15-bit color here. It | '''CGRAM''' (Color Generator<sup>[2]</sup> RAM) is a 512 byte buffer where palettes are stored for [[indirect color]]. The SNES uses 15-bit color here. It is word (not byte) addressed. For each of the 256 color entries: | ||
* bits 0 to 4 are the red intensity | * bits 0 to 4 are the red intensity | ||
* bits 5 to 9 are the green intensity | * bits 5 to 9 are the green intensity | ||
* bits 10 to 14 are the blue intensity | * bits 10 to 14 are the blue intensity | ||
* bit 15 is unused | * bit 15 is unused - reading it returns [[S-PPU2]] [[open bus]] | ||
In all [[background modes]], sprites use the second half of CGRAM (addresses 80h to FFh). | In all [[background modes]], sprites use the second half of CGRAM (addresses 80h to FFh). | ||
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[[Category:Video]] | [[Category:Video]] | ||
[[Category:Address Spaces]] | [[Category:Address Spaces]] | ||
[[Category:Buffers]] | |||
Latest revision as of 04:42, 12 August 2024
CGRAM (Color Generator[2] RAM) is a 512 byte buffer where palettes are stored for indirect color. The SNES uses 15-bit color here. It is word (not byte) addressed. For each of the 256 color entries:
- bits 0 to 4 are the red intensity
- bits 5 to 9 are the green intensity
- bits 10 to 14 are the blue intensity
- bit 15 is unused - reading it returns S-PPU2 open bus
In all background modes, sprites use the second half of CGRAM (addresses 80h to FFh).
When using CGRAM, color entries can be one of 32,768 colors from the master palette.
Direct Color is a technique that does not use CGRAM.
See Also
References
- Appendix A-17 of the official Super Nintendo development manual on CG-RAM
- https://problemkaputt.de/fullsnes.htm#snesmemorycgramaccesspalettememory