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RSRS0 - ADDRESS INPUTS
The address inputs select the internal registers as described by the
register map.
DB7-DB0 - DATA BUS INPUTS/OUTPUTS
The eight data bus output pins transfer information between the 8520 and
the system data bus. These pins are high impedance inputs unless CS is
low and R/W and 02 are high, to read the device. During this read, the
data bus output buffers are enabled, driving the data from the selected
register onto the system data bus.
IRQ - INTERRUPT REQUEST OUTPUT
IRQ is an open drain output normally connected to the processor interrupt
input. An external pull-up resistor holds the signal high, allowing
multiple IRQ outputs to be connected together.
The IRQ output is normally off (high impedance) and is activated low as
indicated in the functional description.
RES - RESET INPUT
A low on the RES pin resets all internal registers. The port pins are set
as inputs and port registers to zero (although a read of the ports will
return all highs because of passive pull-ups). The timer control registers
are set to zero and the timer latches to all ones. All other registers
are reset to zero.
- Appendix F 333 –
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...