Omron CP - PROGRAMMING MANUAL 05-2007 Programming Manual page 358

Increment/Decrement Instructions
Description
Flags
Examples
Area
Index Registers
Indirect addressing
using Index Registers
The – –(592) instruction subtracts 1 from the binary content of Wd. The spec-
ified word will be decremented by 1 every cycle as long as the execution con-
dition of – –(592) is ON. When the up-differentiated variation of this instruction
(@– –(592)) is used, the specified word is decremented only when the execu-
tion condition has gone from OFF to ON.
Wd
The Equals Flag will be turned ON if the result is 0000, the Carry Flag will be
turned ON when a digit changes from 0 to F, and the Negative Flag will be
turned ON if bit 15 of Wd is ON in the result.
Both the Carry Flag and the Negative Flag will be turned ON when the content
of Wd changes from 0000 to FFFF.
Name Label
Error Flag ER
Equals Flag =
Carry Flag CY
Negative Flag N
Operation of – –(592)
In the following example, the content of D100 will be decremented by 1 every
cycle as long as CIO 0.00 is ON.
0.00
D100
---
,IR0 to ,IR15
–2048 to +2047, IR0 to –2048 to +2047, IR15
DR0 to DR15, IR0 to IR15
,IR0+(++) to ,IR15+(++)
,–(– –)IR0 to, –(– –)IR15
Wd
Operation
OFF
ON if the content of Wd is 0000 after execution.
OFF in all other cases.
ON if a digit in Wd went from 0 to F during execution.
OFF in all other cases.
ON if bit 15 of Wd is ON after execution.
OFF in all other cases.
Decremented every cycle
while CIO 0.00 is ON.
Wd: D100
1
: Execution of
CIO 0.00
Decrement Decrement Decrement Decrement
Section 3-9
Wd
Wd: D100
(592)
325