INSTRUCTION DESCRIPTIONS
A - 246 INSTRUCTION SET DETAILS MOTOROLA
Operation: Assembler Syntax:
#xx+D ➞ D OR(I) #xx,D
where + denotes the logical inclusive OR operator
Description: Logically OR the 8-bit immediate operand (#xx) with the contents of the
destination control register D and store the result in the destination control register. The
condition codes are affected only when the condition code register is specified as the
destination operand.
Restrictions: The ORI #xx,MR instruction cannot be used immediately before an
ENDDO or RTI instruction and cannot be one of the last three instructions in a DO loop
(at LA–2, LA–1, or LA).
Example: :
OR #$8,MR ;set scaling mode bit S1 to scale up
:
Explanation of Example: Prior to execution, the 8-bit mode register (MR) contains the
value $03. The OR #$8,MR instruction logically ORs the immediate 8-bit value $8 with
the contents of the mode register and stores the result in the mode register.
Condition Codes:
For CCR operand:
S — Set if bit 7 of the immediate operand is set
L — Set if bit 6 of the immediate operand is set
E — Set if bit 5 of the immediate operand is set
U — Set if bit 4 of the immediate operand is set
N — Set if bit 3 of the immediate operand is set
Z — Set if bit 2 of the immediate operand is set
V — Set if bit 1 of the immediate operand is set
C — Set if bit 0 of the immediate operand is set
ORI OR Immediate with Control Register ORI
Before Execution After Execution
MR $03 $0B
MR
MR CCR
1514131211109876543210
LF DM T ** S1 S0 I1 I0 SLEUNZVC