CHAPTER 5 INTERRUPT/EXCEPTION PROCESSING FUNCTION
User’s Manual U13850EJ4V0UM
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5.2.1 Operation
If the non-maskable interrupt is generated, the CPU performs the following processing, and transfers control to the
handler routine:
(1) Saves the restored PC to FEPC.
(2) Saves the current PSW to FEPSW.
(3) Writes exception code 0010H to the higher half-word (FECC) of ECR.
(4) Sets the NP and ID bits of PSW and clears the EP bit.
(5) Loads the handler address (00000010H, 00000020H) of the non-maskable interrupt routine to the PC, and
transfers control.
Figure 5-1. Non-Maskable Interrupt Servicing
NMI input
Non-maskable interrupt request
Interrupt servicing
Interrupt request pending
FEPC
FEPSW
ECR. FECC
PSW. NP
PSW. EP
PSW. ID
PC
Restored PC
PSW
Exception code
1
0
1
00000010H,
00000020H
INTC accepted
CPU processing
PSW. NP
1
0