SEGA SATURN DEVELOPER'S MANUAL

Figure 4.14 Change in attenuation
D1R [4: 0] (R / W); Decay-1 Rate: Specify the amount of EG change in Decay 1 state.
When "D1R" = "00H", change (level attenuation) is minimum (0)
When "D1R" = "1FH", change (level attenuation) maximum (MAX)
D2R [4: 0] (R / W); Decay-2 Rate: Specify the amount of EG change in Decay 2 state.
When "D2R" = "00H", change (level attenuation) is minimum (0)
When "D2R" = "1FH", change (level attenuation) maximum (MAX)