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CONTROL REGISTERS
There are two control registers in the 8520, CRA and CRB. CRA is
associated with Timer A and CRB is associated with Timer B. The format of
the registers is as follows:
CONTROL REGISTER A
BIT NAME FUNCTION
0 START 1 = start Timer A, 0 - top Timer A.
This bit is automatically reset (= 0) when
underflow occurs during one-shot mode.
1 PBON 1 = Timer A output on PB6, 0 = PB6 is normal operation.
2 OUTMODE 1 = toggle, 0 = pulse.
3 RUNMODE 1 = one-shot mode, 0 = continuous mode.
4 LOAD 1 = force load (this is a strobe input, there is no
data storage; bit 4 will always read back a zero
and writing a 0 has no effect.)
5 INMODE 1 = Timer A count positive CNT transition,
0 = Timer A counts 02 pulses.
6 SPMODE 1 = Serial port=output (CNT is the source of the shift
clock)
0 = Serial port-input (external shift clock is
required)
7 UNUSED
- Appendix F 327 -
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...