Difference between revisions of "DMA channel usage in SMW"

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(Recovered from SMWiki, improvements are welcome.)
 
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Latest revision as of 23:15, 9 November 2019

This is a list of all the uses for DMA/HDMA channels in SMW and what they are used for.

For DMA channels, the channel corresponds to a bit of $420B. For HDMA channels, the channel corresponds to a bit of $0D9F, which is SMW's mirror for $420C, the register used for HDMA on the SNES.

  • Channel 0:
    • (DMA) Used for transferring data from the OAM mirror RAM ($0200) to the actual OAM address.
  • Channel 1:
    • (DMA) Used for uploading Layer 3 tilemap data.
    • (DMA) Used for uploading Layer 1 tilemap data on the overworld (?).
  • Channel 2:
    • (DMA) Used for uploading the background palette to CGRAM.
    • (DMA) Used to upload data to SP4 in some special levels (?).
    • (DMA) Used for uploading the player graphics.
    • (DMA) Used for uploading other dynamic tiles in SP1 (?).
  • Channel 3:
    • Not used in SMW. This channel is commonly used for custom HDMA effects.
  • Channel 4:
    • Not used in SMW. This channel is commonly used for custom HDMA effects.
  • Channel 5:
    • (HDMA) Used during the ending enemy presentation, and that seems to be its only use in SMW. This channel is commonly used for custom HDMA effects.
  • Channel 6:
    • (HDMA) Used during the ending enemy presentation, and that seems to be its only use in SMW.
  • Channel 7:
    • (HDMA) Used for the level end windowing circle.
    • (HDMA) used for the windowing HDMA that the dark room spotlight creates.
    • (HDMA) Used during the ending enemy presentation.