UPD78F9418A NEC, UPD78F9418A Datasheet - Page 232

• Manufacturer Part Number: UPD78F9418A
• Description: (UPD7894xxA) 8-Bit Single Chip Microcontrollers
• Manufacturer: NEC

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232
(1)
Symbol
Cautions 1. The TMIF4 flag is R/W enabled only when the watchdog timer is used as an interval timer. If
IF0
IF1
Interrupt request flag registers 0, 1 (IF0 and IF1)
The interrupt request flag is set to 1 when the corresponding interrupt request is generated or an instruction
is executed. It is cleared to 0 when an instruction is executed upon acknowledgment of an interrupt request
or upon RESET input.
IF0 and IF1 are set using a 1-bit or 8-bit memory manipulation instruction.
RESET input sets IF0 and IF1 to 00H.
CMPIF0 ADIF0 KRIF00 TMIF50 TMIF02 TMIF01 TMIF00 WTIIF
XXIFX
WTIF STIF00 SRIF00 PIF3
<7>
<7>
0
1
2. Because port 2 has an alternate function as an external interrupt input, when the output level
3. If an interrupt is acknowledged, the interrupt request flag is automatically cleared before the
watchdog timer mode 1 or 2 is used, set the TMIF4 flag to 0.
is changed by specifying the output mode of the port function, an interrupt request flag is
set. Therefore, the interrupt mask flag should be set to 1 before using the output mode.
interrupt routine is entered.
<6>
<6>
No interrupt request signal is generated
Interrupt request signal is generated; Interrupt request state
<5>
<5>
Figure 15-2. Format of Interrupt Request Flag Register
<4>
<4>
PIF2
<3>
<3>
CHAPTER 15 INTERRUPT FUNCTIONS
PIF1
<2>
<2>
User’s Manual U13952EJ3V0UD
PIF0 TMIF4
<1>
<1>
Interrupt request flag
<0>
<0>
Address
FFE0H
FFE1H
After reset
00H
00H
R/W
R/W
R/W