INSTRUCTION DESCRIPTIONS
MOTOROLA INSTRUCTION SET DETAILS A - 107
Restrictions: A Jcc instruction used within a DO loop cannot begin at the address LA
within that DO loop.
A Jcc instruction cannot be repeated using the REP instruction.
Example: :
JNN – (R4) ;jump to P:(R4) –1 if not normalized
:
Explanation of Example: In this example, program execution is transferred to the
address P:(R4)–1 if the result is not normalized. Note that the contents of address regis-
ter R4 are predecremented by 1, and the resulting address is then loaded into the pro-
gram counter (PC) if the specified condition is true. If the specified condition is not true,
no jump is taken, and the program counter is incremented by one.
Condition Codes:
The condition codes are not affected by this instruction.
Instruction Format:
Jcc xxx
Opcode:
Jcc Jump Conditionally Jcc
MR CCR
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
LF DM T ** S1 S0 I1 I0 S L E U N Z V C
23 16 15 8 7 0
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