Chapter 20 Key Interrupt Function; Functions Of Key Interrupt; Configuration Of Key Interrupt - NEC 78K0 User Manual

20.1 Functions of Key Interrupt

A key interrupt (INTKR) can be generated by setting the key return mode register (KRM) and inputting a falling
edge to the key interrupt input pins (KR0 to KR7).

20.2 Configuration of Key Interrupt

The key interrupt consists of the following hardware.
KR7
KR6
KR5
KR4
KR3
KR2
KR1
KR0
KRM7 KRM6 KRM5 KRM4 KRM3 KRM2 KRM1 KRM0
Key return mode register (KRM)
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CHAPTER 20 KEY INTERRUPT FUNCTION

Table 20-1. Assignment of Key Interrupt Detection Pins
Flag
KRM0 Controls KR0 signal in 1-bit units.
KRM1 Controls KR1 signal in 1-bit units.
KRM2 Controls KR2 signal in 1-bit units.
KRM3 Controls KR3 signal in 1-bit units.
KRM4 Controls KR4 signal in 1-bit units.
KRM5 Controls KR5 signal in 1-bit units.
KRM6 Controls KR6 signal in 1-bit units.
KRM7 Controls KR7 signal in 1-bit units.
Table 20-2. Configuration of Key Interrupt
Item
Control register Key return mode register (KRM)
Figure 20-1. Block Diagram of Key Interrupt
User's Manual U15947EJ2V0UD
Description
*
Configuration
Edge detector
INTKR