Propeller Manual

3: Assembly Language Reference – WZ
WZ
Effect: Cause assembly instruction to modify the Z flag.
〈Label〉 〈Condition〉 Instruction Operands WZ
Result: Z flag is updated with status from the Instruction‘s execution.
• Label is an optional statement label. See Common Syntax Elements on page 250.
•
Condition is an optional execution condition. See Common Syntax Elements on page 250.
•
Instruction is the desired assembly instruction.
•
Operands is zero, one, or two operands as required by the Instruction.
Explanation
WZ (Write Z flag) is one of four optional effects (NR, WR, WC, and WZ) that influence the
behavior of assembly instructions.
WZ causes an executing assembly instruction to modify the
Z flag in accordance with its results.
For example, the
CMP (Compare Unsigned) instruction compares two values (destination and
source) but does not automatically write the results to the C and Z flags. You can determine
if the destination value is equal to the source value by using the
CMP instruction with the WZ
effect:
cmp value1, value2 WZ 'Z = 1 if value1 = value2
The above CMP instruction compares value1 with value2 and sets Z high (1) if value1 is
equal to
value2.
See Effects on page 291 for more information.
Propeller Manual v1.1 · Page 377