CONTENTS
viii
9.2.4 Pulsed and Variable Duty Cycle Output ..................................................................9-14
9.2.5 Enabling/Disabling Counters ...................................................................................9-15
9.2.6 Timer Interrupts .......................................................................................................9-16
9.2.7 Programming Considerations ..................................................................................9-16
9.3 TIMING ........................................................................................................................ 9-16
9.3.1 Input Setup and Hold Timings .................................................................................9-16
9.3.2 Synchronization and Maximum Frequency .............................................................9-17
9.3.2.1 Timer/Counter Unit Application Examples .....................................................9-17
9.3.3 Real-Time Clock .....................................................................................................9-17
9.3.4 Square-Wave Generator .........................................................................................9-17
9.3.5 Digital One-Shot ......................................................................................................9-17
CHAPTER 10
DIRECT MEMORY ACCESS UNIT
10.1 FUNCTIONAL OVERVIEW.......................................................................................... 10-1
10.1.1 The DMA Transfer ..................................................................................................10-1
10.1.1.1 DMA Transfer Directions ...............................................................................10-3
10.1.1.2 Byte and Word Transfers ..............................................................................10-3
10.1.2 Source and Destination Pointers ............................................................................10-3
10.1.3 DMA Requests ........................................................................................................10-3
10.1.4 External Requests ...................................................................................................10-4
10.1.4.1 Source Synchronization ................................................................................10-5
10.1.4.2 Destination Synchronization ..........................................................................10-5
10.1.5 Internal Requests ....................................................................................................10-6
10.1.5.1 Timer 2-Initiated Transfers .............................................................................10-6
10.1.5.2 Unsynchronized Transfers ............................................................................10-6
10.1.6 DMA Transfer Counts .............................................................................................10-7
10.1.7 Termination and Suspension of DMA Transfers .....................................................10-7
10.1.7.1 Termination at Terminal Count ......................................................................10-7
10.1.7.2 Software Termination ....................................................................................10-7
10.1.7.3 Suspension of DMA During NMI ...................................................................10-7
10.1.7.4 Software Suspension ....................................................................................10-7
10.1.8 DMA Unit Interrupts ................................................................................................10-8
10.1.9 DMA Cycles and the BIU ........................................................................................10-8
10.1.10 The Two-Channel DMA Unit ...................................................................................10-8
10.1.10.1 DMA Channel Arbitration ...............................................................................10-8
10.2 PROGRAMMING THE DMA UNIT ............................................................................ 10-10
10.2.1 DMA Channel Parameters ....................................................................................10-10
10.2.1.1 Programming the Source and Destination Pointers ....................................10-10
10.2.1.2 Selecting Byte or Word Size Transfers ........................................................10-14
10.2.1.3 Selecting the Source of DMA Requests ......................................................10-17
10.2.1.4 Arming the DMA Channel ............................................................................10-18
10.2.1.5 Selecting Channel Synchronization .............................................................10-18
10.2.1.6 Programming the Transfer Count Options ...................................................10-18
10.2.1.7 Generating Interrupts on Terminal Count ....................................................10-19
Содержание 80C186EA
Страница 1: ...80C186EA 80C188EA Microprocessor User s Manual...
Страница 2: ...80C186EA 80C188EA Microprocessor User s Manual 1995...
Страница 19: ......
Страница 20: ...1 Introduction...
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Страница 28: ...2 Overview of the 80C186 Family Architecture...
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Страница 80: ...3 Bus Interface Unit...
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Страница 130: ...4 Peripheral Control Block...
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Страница 140: ...5 ClockGenerationand Power Management...
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Страница 166: ...6 Chip Select Unit...
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Страница 190: ...7 Refresh Control Unit...
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Страница 206: ...8 Interrupt Control Unit...
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Страница 239: ...INTERRUPT CONTROL UNIT 8 32...
Страница 240: ...9 Timer Counter Unit...
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Страница 266: ...10 Direct Memory Access Unit...
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Страница 295: ...DIRECT MEMORY ACCESS UNIT 10 28...
Страница 296: ...11 Math Coprocessing...
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Страница 314: ...12 ONCE Mode...
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Страница 318: ...A 80C186 Instruction Set Additions and Extensions...
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Страница 330: ...B Input Synchronization...
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Страница 334: ...C Instruction Set Descriptions...
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Страница 383: ...INSTRUCTION SET DESCRIPTIONS C 48...
Страница 384: ...D Instruction Set Opcodes and Clock Cycles...
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Страница 408: ...Index...
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