AMD Am186 Series, Набор инструкций

Страница: 32 / 320

Instruction Set Listing 3-6
Stack Movement Instructions
General I/O Movement Instructions
String I/O Movement Instructions
Flag Movement Instructions
3.1.7 Decimal Arithmetic
In addition to binary arithmetic, the microcontroller supports arithmetic using numbers
represented in the binary-coded decimal (BCD) system. The BCD system uses four bits to
represent a single decimal digit. When two decimal digits are stored in a byte, the number
is called a
packed decimal number. When only one decimal digit is stored in a byte, the
number is called an
unpacked decimal number.
To perform decimal arithmetic, the microcontroller uses a subset of the binary arithmetic
instructions and a special set of instructions that convert unsigned binary numbers to
decimal.
Arithmetic Instructions That Are Used with Decimal Numbers
Mnemonic Name See Page
POP Pop Component from Stack 4-175
POPA Pop All 16-Bit General Registers from Stack 4-178
POPF Pop Flags from Stack 4-180
PUSH Push Component onto Stack 4-181
PUSHA Push All 16-Bit General Registers onto Stack 4-184
PUSHF Push Flags onto Stack 4-186
Mnemonic Name See Page
IN Input Component from Port 4-67
OUT Output Component to Port 4-171
Mnemonic Name See Page
INS Input String Component from Port 4-71
INSB Input String Byte from Port ( Synonym for INS) 4-71
INSW Input String Word from Port ( Synonym for INS) 4-71
OUTS Output String Component to Port 4-173
OUTSB Output String Byte to Port ( Synonym for OUTS) 4-173
OUTSW Output String Word to Port ( Synonym for OUTS) 4-173
Mnemonic Name See Page
LAHF Load AH with Flags 4-129
SAHF Store AH in Flags 4-209
Mnemonic Name See Page
ADD Add Numbers 4-14
DIV Divide Unsigned Numbers 4-50
MUL Multiply Unsigned Numbers 4-160
SUB Subtract Numbers 4-240