INSTRUCTION SET DESCRIPTIONS
C-8
CBW
Convert Byte to Word:
CBW
Extends the sign of the byte in register
AL throughout register AH. Use to
produce a double-length (word)
dividend from a byte prior to
performing byte division.
Instruction Operands:
none
if
(AL) < 80H
then
(AH)
←
0
else
(AH)
←
FFH
AF –
CF –
DF –
IF –
OF –
PF –
SF –
TF –
ZF –
CLC
Clear Carry flag:
CLC
Zeroes the carry flag (CF) and affects
no other flags. Useful in conjunction
with the rotate through carry left (RCL)
and the rotate through carry right
(RCR) instructions.
Instruction Operands:
none
(CF)
←
0
AF –
CF
ü
DF –
IF –
OF –
PF –
SF –
TF –
ZF –
CLD
Clear Direction flag:
CLD
Zeroes the direction flag (DF) causing
the string instructions to auto-
increment the source index (SI) and/or
destination index (DI) registers.
Instruction Operands:
none
(DF)
←
0
AF –
CF –
DF
ü
IF –
OF –
PF –
SF –
TF –
ZF –
Table C-4. Instruction Set (Continued)
Name
Description
Operation
Flags
Affected
NOTE: The three symbols used in the Flags Affected column are defined as follows:
– the contents of the flag remain unchanged after the instruction is executed
? the contents of the flag is undefined after the instruction is executed
ü
the flag is updated after the instruction is executed
Содержание 80C186EA
Страница 1: ...80C186EA 80C188EA Microprocessor User s Manual...
Страница 2: ...80C186EA 80C188EA Microprocessor User s Manual 1995...
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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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