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Indirectly Addressing the DM and EM Areas Section 4-8
4-8 Indirectly Addressing the DM and EM Areas
The DM and EM areas can be addressed either directly or indirectly. Indirect
addresses are indicated using an asterisk before the address, e.g., *DM
0000.
Direct Addresses
Indirect Addresses With indirect addresses, the contents of the address given in the operand is
treated as BCD and used as the final address in the EM or DM area.
Note The contents of a word used as an indirect must be BCD and must not exceed
the addressing range of the DM or EM area. If it is not BCD, a BCD error will
occur. If the DM or EM area is exceeded, an indirect addressing error will
occur. The Error Flag (SR 25503) will turn ON for either of these errors and
the instruction will not be executed.
#FFFF
DM 0000 FFFF
When IR 00000 is ON, the constant FFFF is moved to DM 0000.
00000
MOV(21)
#FFFF
DM 0000
•
DM 0123 #FFFF
0123DM 0000 #FFFF
When IR 00000 is ON, the constant FFFF is moved to the address
specified in DM 0000, i.e., DM 0123.
00000
MOV(21)
#FFFF
*
DM 0000
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