Mitsubishi MELSEC iQ-F FX5 series Programming Manual page 335

• By executing the EI instruction, the interrupt with the priority disabled by the counterpart DI instruction is enabled. However,
when interrupts are disabled only with the DI instruction without an argument, interrupts with all the priorities are enabled by
executing the EI instruction once.
EI, which is the
counterpart of [DI K2]
EI, which is the
counterpart of [DI K3]
• Interrupts (requests) that are generated after the DI instruction are processed after the EI instruction is executed.
• When multiple DI instructions are executed and the argument has a priority higher than the currently disabled priority,
interrupts with a priority lower than that of the argument are disabled.
• When multiple DI instructions are executed and the argument has a priority lower than the currently disabled priority, the
interrupt disabled state is not changed.
• The DI instruction can be nested in up to 16 levels.
• The interrupt priority of the interrupt pointer can be set with parameters. (MELSEC iQ-F FX5 Series User's Manual
[Application])
• The interrupt-disabled priority can be checked with SD758 (interrupt-disabling priority setting value).
• The following shows the interrupt-disabled section when the DI or EI instruction is executed.
• When multiple DI instructions are executed (when interrupts with a priority higher than the currently disabled priority are specified and disabled)
Scan execution type
program
EI
Time
(1) Interrupt-enabled section for all priority
(2) Interrupt-disabled section for the priority 3 or lower (interrupt-enabled section for the priority 2 or higher)
(3) Interrupt-disabled section for the priority 2 or lower (interrupt-enabled section for the priority 1 or higher)
• When multiple DI instructions are executed (when interrupts with a priority lower than the currently disabled priority are specified and disabled)
Scan execution type
program
EI
Time
(1) Interrupt-enabled section for all priority
(2) Interrupt-disabled section for the priority 2 or lower (interrupt-enabled section for the priority 1 or higher)
(3) Because interrupts with the priority 2 or lower are already disabled, the interrupt-disabling priority is not changed.
EI
Sequence program
DI K3
Sequence program
DI K2
Sequence program
EI
Sequence program
EI
Sequence program
(1) (2) (3)
DI K3 DI K2
(1) (2)
DI K2 DI K3
(3)
(1) Interrupt-enabled section for all priority
(2) Interrupt-disabled section for the priority 3 or lower
(Interrupt-enabled section for the priority 2 or higher)
(1)
(3) Interrupt-disabled section for the priority 2 or lower
(Interrupt-enabled section for the priority 1 or higher)
(4) Interrupt-disabled section for the priority 3 or lower
(2)
(Interrupt-enabled section for the priority 2 or higher)
(5) Interrupt-enabled section for all priority
(3)
(4)
(5)
(2) (1)
EI EI
(1)
EI EI
7 APPLICATION INSTRUCTION
7.3 Program execution control instruction
7
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