CONTENTS
iv
2.3
INTERRUPTS AND EXCEPTION HANDLING ............................................................ 2-39
2.3.1
Interrupt/Exception Processing ...............................................................................2-39
2.3.1.1
Non-Maskable Interrupts ...............................................................................2-42
2.3.1.2
Maskable Interrupts .......................................................................................2-43
2.3.1.3
Exceptions .....................................................................................................2-43
2.3.2
Software Interrupts ..................................................................................................2-45
2.3.3
Interrupt Latency .....................................................................................................2-45
2.3.4
Interrupt Response Time ........................................................................................2-46
2.3.5
Interrupt and Exception Priority ...............................................................................2-46
CHAPTER 3
BUS INTERFACE UNIT
3.1
MULTIPLEXED ADDRESS AND DATA BUS ................................................................ 3-1
3.2
ADDRESS AND DATA BUS CONCEPTS ..................................................................... 3-1
3.2.1
16-Bit Data Bus .........................................................................................................3-1
3.2.2
8-Bit Data Bus ...........................................................................................................3-5
3.3
MEMORY AND I/O INTERFACES................................................................................. 3-6
3.3.1
16-Bit Bus Memory and I/O Requirements ...............................................................3-7
3.3.2
8-Bit Bus Memory and I/O Requirements .................................................................3-7
3.4
BUS CYCLE OPERATION ............................................................................................ 3-7
3.4.1
Address/Status Phase ............................................................................................3-10
3.4.2
Data Phase .............................................................................................................3-13
3.4.3
Wait States ..............................................................................................................3-13
3.4.4
Idle States ...............................................................................................................3-18
3.5
BUS CYCLES .............................................................................................................. 3-20
3.5.1
Read Bus Cycles ....................................................................................................3-20
3.5.1.1
Refresh Bus Cycles .......................................................................................3-22
3.5.2
Write Bus Cycles .....................................................................................................3-22
3.5.3
Interrupt Acknowledge Bus Cycle ...........................................................................3-25
3.5.3.1
System Design Considerations .....................................................................3-27
3.5.4
HALT Bus Cycle ......................................................................................................3-28
3.5.5
Temporarily Exiting the HALT Bus State .................................................................3-30
3.5.6
Exiting HALT ...........................................................................................................3-32
3.6
SYSTEM DESIGN ALTERNATIVES ........................................................................... 3-33
3.6.1
Buffering the Data Bus ............................................................................................3-34
3.6.2
Synchronizing Software and Hardware Events .......................................................3-36
3.6.3
Using a Locked Bus ................................................................................................3-37
3.6.4
Using the Queue Status Signals .............................................................................3-38
3.7
MULTI-MASTER BUS SYSTEM DESIGNS................................................................. 3-39
3.7.1
Entering Bus HOLD ................................................................................................3-39
3.7.1.1
HOLD Bus Latency ........................................................................................3-40
3.7.1.2
Refresh Operation During a Bus HOLD ........................................................3-41
3.7.2
Exiting HOLD ..........................................................................................................3-43
3.8
BUS CYCLE PRIORITIES ........................................................................................... 3-44
Содержание 80C186XL
Страница 1: ...80C186XL 80C188XL Microprocessor User s Manual...
Страница 2: ...80C186XL 80C188XL Microprocessor User s Manual 1995...
Страница 18: ...1 Introduction...
Страница 19: ......
Страница 27: ......
Страница 28: ...2 Overview of the 80C186 Family Architecture...
Страница 29: ......
Страница 79: ......
Страница 80: ...3 Bus Interface Unit...
Страница 81: ......
Страница 127: ......
Страница 128: ...4 Peripheral Control Block...
Страница 129: ......
Страница 137: ......
Страница 138: ...5 ClockGenerationand Power Management...
Страница 139: ......
Страница 154: ...6 Chip Select Unit...
Страница 155: ......
Страница 178: ...7 Refresh Control Unit...
Страница 179: ......
Страница 193: ......
Страница 194: ...8 Interrupt Control Unit...
Страница 195: ......
Страница 227: ......
Страница 228: ...9 Timer Counter Unit...
Страница 229: ......
Страница 253: ......
Страница 254: ...10 Direct Memory Access Unit...
Страница 255: ......
Страница 283: ......
Страница 284: ...11 Math Coprocessing...
Страница 285: ......
Страница 302: ...12 ONCE Mode...
Страница 303: ......
Страница 306: ...A 80C186 Instruction Set Additions and Extensions...
Страница 307: ......
Страница 318: ...B Input Synchronization...
Страница 319: ......
Страница 322: ...C Instruction Set Descriptions...
Страница 323: ......
Страница 371: ......
Страница 372: ...D Instruction Set Opcodes and Clock Cycles...
Страница 373: ......
Страница 396: ...Index...
Страница 397: ......