Registers Controlling Interrupt Functions - NEC 78K0 User Manual

(C) External maskable interrupt (INTKR)
Interrupt
request
1 when KRMn = 1 (n = 0 to 7)
(D) Software interrupt
Interrupt
request
IF: Interrupt request flag
IE: Interrupt enable flag
ISP: In-service priority flag
MK: Interrupt mask flag
PR: Priority specification flag
KRM: Key return mode register

19.3 Registers Controlling Interrupt Functions

The following 6 types of registers are used to control the interrupt functions.
• Interrupt request flag register (IF0L, IF0H, IF1L, IF1H)
• Interrupt mask flag register (MK0L, MK0H, MK1L, MK1H)
• Priority specification flag register (PR0L, PR0H, PR1L, PR1H)
• External interrupt rising edge enable register (EGP)
• External interrupt falling edge enable register (EGN)
• Program status word (PSW)
Table 19-2 shows a list of interrupt request flags, interrupt mask flags, and priority specification flags corresponding
to interrupt request sources.
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CHAPTER 19 INTERRUPT FUNCTIONS
Figure 19-1. Basic Configuration of Interrupt Function (2/2)
Internal bus
MK
Key
IF
interrupt
detector
User's Manual U15947EJ2V0UD
IE PR ISP
Priority controller
Internal bus
*
Vector table
Priority controller
address generator
Vector table
address generator
Standby release signal