Zilog Z08470 - Manual (Page 192)

Z80 Instruction Set UM008007-0715
180
Z80 CPU
User Manual
DI
Operation
IFF ← 0
Op Code
DI
Operands
None.
Description
DI disables the maskable interrupt by resetting the interrupt enable flip-flops (IFF1 and
IFF2).
This instruction disables the maskable interrupt during its execution.
Condition Bits Affected
None.
Example
When the CPU executes the instruction DI the maskable interrupt is disabled until it is
subsequently re-enabled by an EI instruction. The CPU does not respond to an Interrupt
Request (INT) signal.
M Cycles T States 4 MHz E.T.
1 4 1.00
1 1 1 1 1 0 1 0 F3
Note: