S3F9498 Datasheet, PDF (102/239 Pages) Samsung semiconductor – 8-BIT CMOS MICROCONTROLLER

S3C9498/F9498
SAM88RCRI INSTRUCTION SET
EI — Enable Interrupts
EI
Operation:
SYM (3) _ 1
An EI instruction sets bit 3 of the system mode register, SYM.3 to "1". This allows interrupts to be
serviced as they occur. If an interrupt's pending bit was set while interrupt processing was disabled
(by executing a DI instruction), it will be serviced when you execute the EI instruction.
Flags:
Format:
No flags are affected.
opc
Bytes
1
Cycles
4
Opcode
(Hex)
9F
Example:
Given: SYM = 00H:
EI
If the SYM register contains the value 00H, that is, if interrupts are currently disabled, the statement
"EI" sets the SYM register to 08H, enabling all interrupts. (SYM.3 is the enable bit for global interrupt
processing.)
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