ZiLOG Z8 - Page 170

Z8 Microcontrollers
Instruction Descriptions and Formats ZiLOG
12-30 UM001601-0803
EI
ENABLE INTERRUPTS
EI
Enable Interrupts
EI
Instruction Format:
Operation:
IMR (7) <— 0
Bit 7 of Control Register FBH (the Interrupt Mask Register) is set to 1. This allows potentially enabled interrupts
to become enabled.
Example:
If Control Register FBH contains 0AH (00001010) (interrupts IRQ1 and IRQ3 are selected), the statement:
EI
Op Code: 9F
sets Control Register FBH to 8AH (10001010B) and enables IRQ1 and IRQ3.
Flags: C: Unaffected
Z: Unaffected
S: Unaffected
V: Unaffected
D: Unaffected
H: Unaffected