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Figure 5.4: Waveform with Multiple Cycles
EFFICIENCY
A certain amount of overhead is involved in the handling of audio DMA. If you are trying
to produce a smooth continuous audio synthesis, you should try to avoid as much of the
system control overhead as possible. Basically, the larger the audio buffer you provide to
the system, the less often it will need to interrupt to reset the pointers to the top of the
next buffer and, coincidentally, the lower the amount of system interaction that will be
required. If there is only one waveform buffer, the hardware automatically resets the
pointers, so no software overhead is used for resetting them.
The "Joining Tones" section illustrated how you could join "ends" of tones together by
responding to interrupts and changing the values of the location registers to splice tones
together. If your system is heavily loaded, it is possible that the response to the interrupt
might not happen in time to assure a smooth audio transition. Therefore, it is advisable to
utilize the longest possible audio Table where a smooth output is required. This takes
advantage of the audio DMA capability as well as minimizing the number of interrupts to
which the 68000 must respond.
- Audio Hardware 149 -
Содержание Amiga A1000
Страница 1: ...AMIGA HARDWARE REFERENCE MANUAL 1992 Commodore Business Machines Amiga 1200 PAL...
Страница 20: ...Figure 1 1 Block Diagram for the Amiga Computer Family Introduction 11...
Страница 21: ...12 Introduction...
Страница 72: ...Figure 3 12 A dual Playfield display Playfield Hardware 63...
Страница 87: ...Figure 3 24 Horizontal Scrolling 78 playfield hardware...
Страница 101: ...92 Playfield Hardware...
Страница 199: ...Figure 6 9 DMA time slot allocation 190 Blitter hardware...
Страница 203: ...Figure 6 13 Blitter Block Diagram 194 Blitter Hardware...
Страница 229: ...220 System Control Hardware...
Страница 246: ...Figure 8 8 Chinon Timing diagram cont Interface Hardware 237...
Страница 265: ...256 Interface Hardware...
Страница 289: ...280 Appendix A...
Страница 297: ...288 Appendix B...
Страница 298: ...APPENDIX C CUSTOM CHIP PIN ALLOCATION LIST NOTE Means an active low signal Appendix C 289...
Страница 302: ...APPENDIX D SYSTEM MEMORY MAP Appendix D 293...
Страница 343: ...334 Appendix F...
Страница 351: ...342 Appendix G...
Страница 361: ...352 Appendix H...
Страница 367: ...358 Appendix I...