CHAPTER 17 INTERRUPT/EXCEPTION PROCESSING FUNCTION
User’s Manual U16896EJ2V0UD
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17.3.7 ID flag
The interrupt disable flag (ID) is allocated to the PSW and controls the maskable interrupt’s operating state, and
stores control information regarding enabling/disabling reception of interrupt request signals.
Reset sets this flag to 00000020H.
0
NP
EP
ID SAT CY
OV
S
Z
PSW
Maskable interrupt request signal acknowledgment enabled
Maskable interrupt request signal acknowledgment disabled
ID
0
1
Maskable interrupt servicing specification
Note
After reset: 00000020H
Note
Interrupt disable flag (ID) function
ID is set (1) by the DI instruction and cleared (0) by the EI instruction. Its value is also
modified by the RETI instruction or LDSR instruction when referencing the PSW.
Non-maskable interrupt request signals and exceptions are acknowledged regardless of
this flag. When a maskable interrupt request signal is acknowledged, the ID flag is
automatically set (1) by hardware.
An interrupt request signal generated during the acknowledgment disabled period (ID flag
= 1) can be acknowledged when the xxICn.xxIFn bit is set (1), and the ID flag is cleared
(0).
Содержание ?PD703302
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