SEGA SATURN DEVELOPER'S MANUAL

Level-0 DMA operation flag (11 [bit 4] in Figure 3.13)
D0MV (R) DMA level 0 MoVe flag: Indicates that level 0 DMA transfer is currently being executed. When it is 1, it indicates that it is currently operating. When it is 0, it indicates that the DMA issued by DSP is not operating. Also, when D0WT, D0MV, and D0BK are all 0, it indicates that the level 0 DMA is stopped.
DSP side DMA waiting flag (12 [bit 1] in Figure 3.13)
DDWT (R) DMA DSP WaiT flag: Indicates that DMA transfer issued by DSP is currently waiting. When it is 1, it indicates that it is currently waiting, and when it is 0, it indicates that the DSP-issued DMA is not waiting.
DSP side DMA operation flag (13 [bit 0] in Figure 3.13)
DDMV (R) DMA DSP MoVe flag: Indicates that DMA transfer execution issued by DSP is currently in operation. When it is 1, it indicates that it is currently operating. When it is 0, it indicates that the DMA issued by DSP is not operating. When DDWT, DDMV, and D0BK are all 0, the DSP DMA is stopped.