Filter
Top Products
580
APPENDIX
B.3 Direct Addressing
An operand value, register, or address is specified explicitly in direct addressing mode.
■ Direct Addressing
●
Immediate addressing (#imm)
Specify an operand value explicitly (#imm4/ #imm8/ #imm16/ #imm32).
Figure B.3-1 Example of Immediate Addressing (#imm)
●
Register direct addressing
Specify a register explicitly as an operand. Table B.3-1 lists the registers that can be specified. Figure B.3-2
shows an example of register direct addressing.
MOVW A, #01212H (This instruction stores the operand value in A.)
Before execution
A 2 2 3 3 4 4 5 5
After execution A 4 4 5 5 1 2 1 2
(Some instructions transfer AL to AH.)
Table B.3-1 Direct Addressing Registers
General-purpose register
Byte R0, R1, R2, R3, R4, R5, R6, R7
Word
RW0, RW1, RW2, RW3, RW4, R5W, RW6,
RW7
Long word RL0, RL1, RL2, RL3
Special-purpose register
Accumulator A, AL
Pointer SP *
Bank PCB, DTB, USB, SSB, ADB
Page DPR
Control PS, CCR, RP, ILM
*: One of the user stack pointer (USP) and system stack pointer (SSP) is selected and used depending
on the value of the S flag bit in the condition code register (CCR). For branch instructions, the
program counter (PC) is not specified in an instruction operand but is specified implicitly.