CHAPTER 13 INTERRUPT FUNCTIONS
User’s Manual U17446EJ3V1UD
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(4) External interrupt mode register 1 (INTM1)
INTM1 is used to specify the valid edge for INTP3.
INTM1 is set with an 8-bit memory manipulation instruction.
Reset signal generation clears INTM1 to 00H.
Figure 13-5. Format of External Interrupt Mode Register 1 (INTM1)
Address: FFEDH After reset: 00H R/W
Symbol
7 6 5 4 3 2 1 0
INTM1
0 0 0 0 0 0
ES31
ES30
ES31
ES30
INTP3 valid edge selection
0
0
Falling
edge
0
1
Rising
edge
1
0
Setting
prohibited
1
1
Both rising and falling edges
Cautions 1. Be sure to clear bits 2 to 7 to 0.
2. Before setting INTM1, set PMK3 to 1 to disable interrupts.
To enable interrupts, clear PIF3 to 0, then clear PMK3 to 0.
(5) Program status word (PSW)
The program status word is used to hold the instruction execution result and the current status of the interrupt
requests. The IE flag, used to enable and disable maskable interrupts, is mapped to PSW.
PSW can be read- and write-accessed in 8-bit units, as well as using bit manipulation instructions and
dedicated instructions (EI and DI). When a vectored interrupt is acknowledged, the PSW is automatically
saved to a stack, and the IE flag is reset to 0.
Generation of reset signal sets PSW to 02H.
Figure 13-6. Program Status Word (PSW) Configuration
IE
Z
0
AC
0
0
1
CY
PSW
Symbol
After reset
02H
7
6
5
4
3
2
1
0
IE
0
1
Disabled
Enabled
Whether to enable/disable interrupt acknowledgment
Used in the execution of ordinary instructions
Содержание 78K0S/KB1+
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