Zilog Z86193 - Manual (Page 187)

Z8
®
CPU
User Manual
UM001604-0108 Instruction Description
180
Disable Interrupts
Syntax
Dl
Instruction Format
Operation
IMR (7)
←
0
Bit 7 of Control Register
FBh
(the Interrupt Mask Register) is reset to 0. All interrupts are
disabled, although they remain potentially enabled. (For example, the Global Interrupt
Enable is cleared, but not the individual interrupt level enables.)
Example
If Control Register
FBh
contains
8Ah
(
10001010
) (interrupts IRQ1 and IRQ3 are
enabled), the statement:
DI
Op Code: 8F
sets Control Register
FBh
to
0Ah
(
00001010b
) and disables these interrupts.
Cycles
OPC
(Hex)
OPC 6 8F
Flag Description
C Unaffected
Z Unaffected
S Unaffected
V Unaffected
D Unaffected
H Unaffected