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CONTENTS
CHAPTER 1
GUIDE TO THIS MANUAL
1.1
MANUAL CONTENTS ................................................................................................... 1-1
1.2
NOTATIONAL CONVENTIONS AND TERMINOLOGY ................................................ 1-3
1.3
RELATED DOCUMENTS .............................................................................................. 1-5
1.3.1
Data Sheet ................................................................................................................1-6
1.3.2
Application Notes ......................................................................................................1-6
1.4
APPLICATION SUPPORT SERVICES.......................................................................... 1-7
1.4.1
World Wide Web .......................................................................................................1-7
1.4.2
CompuServe Forums ................................................................................................1-7
1.4.3
FaxBack Service .......................................................................................................1-8
1.4.4
Bulletin Board System (BBS) ....................................................................................1-8
CHAPTER 2
ARCHITECTURAL OVERVIEW
2.1
8XC251SA, SB, SP, SQ ARCHITECTURE ................................................................... 2-3
2.2
MCS 251 MICROCONTROLLER CORE ....................................................................... 2-4
2.2.1
CPU ..........................................................................................................................2-5
2.2.2
Clock and Reset Unit ................................................................................................2-6
2.2.3
Interrupt Handler .......................................................................................................2-7
2.2.4
On-chip Code Memory ..............................................................................................2-7
2.2.5
On-chip RAM ............................................................................................................2-7
2.3
ON-CHIP PERIPHERALS.............................................................................................. 2-7
2.3.1
Timer/Counters and Watchdog Timer .......................................................................2-7
2.3.2
Programmable Counter Array (PCA) ........................................................................2-8
2.3.3
Serial I/O Port ...........................................................................................................2-8
CHAPTER 3
ADDRESS SPACES
3.1
ADDRESS SPACES FOR MCS® 251 MICROCONTROLLERS................................... 3-1
3.1.1
Compatibility with the MCS® 51 Architecture ...........................................................3-2
3.2
8XC251SA, SB, SP, SQ MEMORY SPACE .................................................................. 3-5
3.2.1
On-chip General-purpose Data RAM ........................................................................3-8
3.2.2
On-chip Code Memory (83C251SA, SB, SP, SQ/87C251SA, SB, SP, SQ) .............3-8
3.2.2.1
Accessing On-chip Code Memory in Region 00: ..................................................3-9
3.2.3
External Memory .....................................................................................................3-10
3.3
8XC251SA, SB, SP, SQ REGISTER FILE .................................................................. 3-10
3.3.1
Byte, Word, and Dword Registers ...........................................................................3-13
3.3.2
Dedicated Registers ................................................................................................3-13
3.3.2.1
Accumulator and B Register ..............................................................................3-13
3.3.2.2
Extended Data Pointer, DPX ..............................................................................3-15
Содержание 8XC251SA
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Страница 3: ...May 1996 8XC251SA 8XC251SB 8XC251SP 8XC251SQ Embedded Microcontroller User s Manual...
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Страница 19: ...1 Guide to This Manual...
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Страница 31: ...2 Architectural Overview...
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Страница 41: ...3 Address Spaces...
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Страница 63: ...4 Device Configuration...
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Страница 81: ...5 Programming...
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Страница 103: ...6 Interrupt System...
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Страница 121: ...7 Input Output Ports...
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Страница 133: ...8 Timer Counters and Watchdog Timer...
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Страница 153: ...9 Programmable Counter Array...
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Страница 171: ...10 Serial I O Port...
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Страница 187: ...11 Minimum Hardware Setup...
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Страница 197: ...12 Special Operating Modes...
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Страница 207: ...13 External Memory Interface...
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Страница 239: ...14 Programming and Verifying Nonvolatile Memory...
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Страница 251: ...A Instruction Set Reference...
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Страница 391: ...B Signal Descriptions...
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Страница 401: ...C Registers...
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Страница 437: ...Glossary...
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Страница 447: ...Index...
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