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CHAPTER 12 INTERRUPT FUNCTIONS
User’s Manual U15104EJ2V0UD
(1) Interrupt request flag registers (IF0L, IF0H)
The interrupt request flags are set to 1 when the corresponding interrupt request is generated or an instruction
is executed. They are cleared to 0 when an instruction is executed upon acknowledgment of an interrupt
request or upon application of reset input.
IF0L and IF0H are set with a 1-bit or 8-bit memory manipulation instruction. If IF0L and IF0H are used as
a 16-bit register IF0, use a 16-bit memory manipulation instruction for the setting.
Reset input clears these registers to 00H.
Figure 12-2. Format of Interrupt Request Flag Registers (IF0L, IF0H)
××
IF
×
Interrupt request flag
0
No interrupt request signal
1
Interrupt request signal is generated;
Interrupt request state
Cautions 1. WDTIF flag is R/W enabled only when a watchdog timer is used as an interval timer. If
a watchdog timer is used in watchdog timer mode 1, set WDTIF flag to 0.
2. To operate the timers, serial interface, and A/D converter after the standby mode has been
released, clear the interrupt request flag, because the interrupt request flag may be set
by noise.
3. When an interrupt is acknowledged, the interrupt request flag is automatically cleared
before entering the interrupt routine.
CSIIF31
TMIF53
KYIF
TMIF52
PIF4
TMIF51
PIF3
TMIF50
PIF2
CSIIF30
PIF1
CSIIF32
PIF0
ADIF
WDTIF
BTMIF0
R/W
R/W
R/W
<0>
<1>
<2>
<3>
<4>
<5>
<6>
<7>
<0>
<1>
<2>
<3>
<4>
<5>
<6>
<7>
After reset
00H
00H
Address
FFE0H
FFE1H
Symbol
IF0L
IF0H