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Continue Flag: Difference between revisions
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The '''Continue Flag''' | The '''Continue Flag''' tells the [[HDMA]] controller whether to continue transferring data after the first transfer unit. It is bit 7 of NTRLx. | ||
When set, the DMA controller sends a single transfer unit to the destination for every [[scanline]], during [[hblank]]. | |||
When clear, the DMA controller sends a transfer unit to the destination just once, for the first scanline, and then does not transfer anything else at least until reaching the Nth scanline, where N was the initial value of the [[HDMA Scanline Counter]]. | |||
=== References === | === References === |
Revision as of 03:41, 27 July 2023
The Continue Flag tells the HDMA controller whether to continue transferring data after the first transfer unit. It is bit 7 of NTRLx.
When set, the DMA controller sends a single transfer unit to the destination for every scanline, during hblank.
When clear, the DMA controller sends a transfer unit to the destination just once, for the first scanline, and then does not transfer anything else at least until reaching the Nth scanline, where N was the initial value of the HDMA Scanline Counter.
References
- page 2-28-13 of Book I of the official Super Nintendo development manual
- the bit cells labeled "C" in the diagrams are the continue flag: Appendix B-2 of Book I, lbid
- https://wiki.superfamicom.org/grog's-guide-to-dma-and-hdma-on-the-snes