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ADVANCED TOPICS
THE SKIP INSTRUCTION
The SKIP instruction causes the Copper to skip the next instruction if the video beam
counters are equal to or greater than the value given in the instruction.
The contents of the SKIP instructions words are shown below. They are identical to the
WAIT instruction, except that bit 0 of the second instruction word is a 1 to identify this as
a SKIP instruction.
FIRST INSTRUCTION WORD (IR1)
Bit 0 Always set to 1.
Bits 15 - 8 Vertical position (called VP).
Bits 7 - 1 Horizontal position (called HP).
Skip if the beam counter is equal to or
greater than these combined bits
(bits 15 through 1).
SECOND INSTRUCTION WORD (IR2)
Bit 0 Always set to 1.
Bit 15 The blitter-finished-disable bit.
(See "Using the Copper with the
Blitter" below.)
Bits 14 - 8 Vertical position compare enable bits (called VE).
Bits 7 - 1 Horizontal position compare enable bits (called HE).
The notes about horizontal and vertical beam position found in the discussion of the WAIT
instruction apply also to the SKIP instruction.
- Coprocessor Hardware 27 -
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...