Chapter 16 Key Interrupt Function; Functions Of Key Interrupt; Configuration Of Key Interrupt - NEC 78K0 User Manual

16.1 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 KR3).

16.2 Configuration of Key Interrupt

The key interrupt includes the following hardware.
Control register
KR3
KR2
KR1
KR0
0 0
Key return mode register (KRM)
330

CHAPTER 16 KEY INTERRUPT FUNCTION

Table 16-1. 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.
Table 16-2. Configuration of Key Interrupt
Item
Key return mode register (KRM)
Figure 16-1. Block Diagram of Key Interrupt
0 0 KRM3 KRM2 KRM1 KRM0
User's Manual U16227EJ2V0UD
Description
Configuration
Edge detector
INTKR