
706
Chapter 17
Interrupt/Exception Processing Function
User’s Manual U16702EE3V2UD00
17.3.7 Maskable interrupt status flag
This flag controls the maskable interrupt’s operating state, and stores control information regarding
enabling or disabling of interrupt requests. An interrupt disable flag (ID) is incorporated, which is
assigned to the PSW.
Figure 17-13:
Maskable Interrupt Status Flag Format
Note:
Interrupt disable flag (ID) function
This bit is set to 1 by the DI instruction and reset to 0 by the EI instruction. Its value is also
modified by the RETI instruction or LDSR instruction when referencing the PSW.
Non-maskable interrupt requests and exceptions are acknowledged regardless of this flag.
When a maskable interrupt is acknowledged, the ID flag is automatically set to 1 by hardware.
The interrupt request generated during the acknowledgement disabled period (ID = 1) is
acknowledged when the xxIFn bit of xxICn is set to 1, and the ID flag is reset to 0.
After reset: 00000021H
31
8
7
6
5
4
3
2
1
0
PSW
0
NP
EP
ID
SAT CY
OV
S
Z
ID
Specification of maskable interrupt servicing
Note
0
Maskable interrupt request signal acknowledgment enabled
1
Maskable interrupt request signal acknowledgment disabled (pending)
electronic components distributor