A-5
80C186 INSTRUCTION SET ADDITIONS AND EXTENSIONS
Figure A-4. Stack Frame for Procedure A at Level 2
After Procedure A calls Procedure B, ENTER creates the display for Procedure B. The first word
of the display points to the previous value of BP (BPA). The second word points to the value of
BP for MAIN (BPM). The third word points to the BP for Procedure A (BPA). The last word
points to the current BP (BPB). Procedure B can access variables in Procedure A or Main via the
appropriate BP in the display (see Figure A-5).
After Procedure B calls Procedure C, ENTER creates the display for Procedure C. The first word
of the display points to the previous value of BP (BPB). The second word points to the value of
BP for MAIN (BPM). The third word points to the value of BP for Procedure A (BPA). The
fourth word points to the current BP (BPC). Because Procedure B and Procedure C have the same
lexical nesting level, Procedure C cannot access variables in Procedure B. The only pointer to
Procedure B in the display of Procedure C exists to allow the LEAVE instruction to collapse the
Procedure C stack frame (see Figure A-6).
Old BP
BP
SP
15
0
BPM
BPM
BPM
BPA*
Display A
Dynamic
Storage A
*BPA = BP Value for Procedure A
A1003-0A
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...
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Страница 254: ...10 Direct Memory Access Unit...
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Страница 284: ...11 Math Coprocessing...
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Страница 302: ...12 ONCE Mode...
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Страница 306: ...A 80C186 Instruction Set Additions and Extensions...
Страница 307: ......
Страница 318: ...B Input Synchronization...
Страница 319: ......
Страница 322: ...C Instruction Set Descriptions...
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Страница 371: ......
Страница 372: ...D Instruction Set Opcodes and Clock Cycles...
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Страница 396: ...Index...
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