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3.2.2 Operating instruction
The operating instructions include the operations of addition and subtraction, logic,
comparison, rotation, and shift.
The operating instructions are as follows:
IN STRUC TION S
Instruction Set
Contents
Add memory contents and C flag to Accumulator or memory
where is indicated by Index Register X
Subtracts memory contents and C flag’s complement from
Accumulator or memory where is indicated by Index
Register X
Increment Accumulator or memory contents by 1
Decrement Accumulator or memory contents by 1
Increment Index Register X by 1
Decrement Index Register X by 1
Increment Index Register Y by 1
Decrement Index Register Y by 1
Multiply Accumulator with memory specified by Zero Page
X addressing mode and store high-order byte of result on
Stack and low-order byte in Accumulator
Quotient is stored in Accumulator and one’s complement of
remainder is pushed onto stack
“AND” memory with Accumulator or memory where is
indicated by Index Register X
“OR” memory with Accumulator or memory where is
indicated by Index Register X
“Exclusive-OR” memory with Accumulator or memory where
is indicated by Index Register X
Store one’s complement of memory contents to memory
“AND” memory with Accumulator (The result is not stored
into anywhere.)
Test whether memory content is “0” or not
Compare memory contents and Accumulator or memory
where is indicated by Index Register X
Compare memory contents and Index Register X
Compare memory contents and Index Register Y
Shift left one bit (memory contents or Accumulator)
Shift right one bit (memory contents or Accumulator)
Rotate one bit left with carry (memory contents or
Accumulator)
Rotate one bit right with carry (memory contents or
Accumulator)
Rotate four bits right witout carry (memory)
Note: For some products, multiplication and division instructions cannot be used.
Instructions
ADC
SBC
INC
DEC
INX
DEX
INY
DEY
MUL (Note)
DIV (Note)
AND
ORA
EOR
COM
BIT
TST
CMP
CPX
CPY
ASL
LSR
ROL
ROR
RRF
Addition
&
Subtraction
Multiplication
&
Division
Logical
Operation
Comparison
Shift
&
Rotate