INSTRUCTION DESCRIPTIONS
A - 284 INSTRUCTION SET DETAILS MOTOROLA
Operation: Assembler Syntax:
If cc, then S1 ➞ D1 Tcc S1,D1
If cc, then S1 ➞ D1 and S2 ➞ D2 Tcc S1,D1 S2,D2
Description: Transfer data from the specified source register S1 to the specified desti-
nation accumulator D1 if the specified condition is true. If a second source register S2
and a second destination register D2 are also specified, transfer data from address reg-
ister S2 to address register D2 if the specified condition is true. If the specified condition
is false, a NOP is executed. The term “cc’’ may specify the following conditions:
“cc’’ Mnemonic Condition
CC (HS) — carry clear (higher or same) C=0
CS (LO) — carry set (lower) C=1
EC — extension clear E=0
EQ — equal Z=1
ES — extension set E=1
GE — greater than or equal N ⊕ V=0
GT — greater than Z+(N ⊕ V)=0
LC — limit clear L=0
LE — less than or equal Z+(N ⊕ V)=1
LS — limit set L=1
LT — less than N ⊕ V=1
MI — minus N=1
NE — not equal Z=0
NR — normalized Z+(U•E)=1
PL — plus N=0
NN — not normalized Z+(U•E)=0
where
U denotes the logical complement of U,
+ denotes the logical OR operator,
• denotes the logical AND operator, and
⊕ denotes the logical Exclusive OR operator
When used after the CMP or CMPM instructions, the Tcc instruction can perform many
useful functions such as a “maximum value,” “minimum value,” “maximum absolute
value,” or “minimum absolute value” function. The desired value is stored in the destina-
Tcc Transfer Conditionally Tcc