Increment/Decrement Instructions
Description
Flags
Examples
0.00
Area
Index Registers
Indirect addressing
using Index Registers
The ++L(591) instruction adds 1 to the 8-digit hexadecimal content of Wd+1
and Wd. The content of the specified words will be incremented by 1 every
cycle as long as the execution condition of ++L(591) is ON. When the up-dif-
ferentiated variation of this instruction (@++L(591)) is used, the content of the
specified words is incremented only when the execution condition has gone
from OFF to ON.
Wd+1
Wd
The Equals Flag will be turned ON if the result is 0000 0000, the Carry Flag
will be turned ON when a digit changes from F to 0, and the Negative Flag will
be turned ON if bit 15 of Wd+1 is ON in the result.
Both the Equals Flag and the Carry Flag will be turned ON when the content
of changes from FFFF FFFF to 0000 0000.
Name
Label
Error Flag
ER
Equals Flag
=
Carry Flag
CY
Negative Flag
N
Operation of ++L(591)
In the following example, the 8-digit hexadecimal content of D101 and D100
will be incremented by 1 every cycle as long as CIO 0.00 is ON.
D100
Wd+1:
D101
CIO 0.00
Increment Increment
IR0 to IR15
,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+1
Wd
OFF
ON if the result is 0000 0000 after execution.
OFF in all other cases.
ON if a digit in Wd+1 or Wd went from F to 0 during
execution.
OFF in all other cases.
ON if bit 15 of Wd+1 is ON after execution.
OFF in all other cases.
Incremented every cycle
while CIO 0.00 is ON.
Wd:
D100
Wd+1:
: Execution of ++L(591)
Increment Increment
Section 3-9
Wd
Operation
D101
Wd:
D100
323
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