MC81F4204
58 April 24, 2012 Ver.1.41
Direct Page Addressing -> dp
In this mode, an address is specified within direct page. Current accessed page is selected by
RPR(RAM Page select Register). And dp( Direct Page ) is an one byte data which indicates the
target address in the current accessed page.
Example :
:;WhenG=0
LDA35h;A=[35h]
:;opcodeis0C5h
:
Absolute Addressing
Absolute addressing sets corresponding memory data to Data, i.e. second byte (Operand I) of
command becomes lower level address and third byte (Operand II) becomes upper level address.
With 3 bytes command, it is possible to access to whole memory area.
ADC, AND, CMP, CMPX, CMPY, EOR, LDA, LDX,LDY, OR, SBC, STA, STX, STY
The operation within data memory (RAM) : ASL, BIT, DEC, INC, LSR, ROL, ROR
Example :
:;WhenG=0
ADC!0F035h;A=A+C+ROM[0F035h]
:;opcodeis07h
:
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