KS57C2308/P2308/C2316/P2316

INTERRUPTS

 

 

Interrupt is generated. ( INT xx)

Request flag (IRQx)

<-- 1

 

 

IEx = 1 ?

NO

Retains value until IEx =1

 

 

 

YES

 

 

Generates

the corresponding vector

 

interrupt and releases power down

 

 

IME = 1 ?

NO

Retains value until IME =1

 

 

 

YES

 

 

YES

 

Retains until interrupt service

 

IS1,0 = 0, 0 ?

 

 

 

 

NO

 

 

routine is completed.

 

 

 

 

 

 

 

 

NO

 

IS1,0 = 0, 1 ?

 

 

 

 

YES

High priority interrupt ?

YES

NO

IS1,0 = 0,1

 

IS1,0 = 1,0

 

 

 

 

 

 

 

 

 

 

 

 

Stores the contents of PC and PSW in stack area; set PC contents to corresponding vector address.

Are both interrupt sources

of shared vector address used?

NO

Reset corresponding IRQx flag

Jump to interrupt start address

YES

IRQx flag value remains 1

Jump to interrupt start address

Verify interrupt source and clear IRQx with a BTSTZ instruction

Figure 7-1. Interrupt Execution Flowchart

7-3

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Image 187
Samsung KS57C2308 manual Interrupt Execution Flowchart