Samsung KS57C2308 Manual page 187

KS57C2308/P2308/C2316/P2316
IS1,0 = 0,1
Reset corresponding IRQx flag
Jump to interrupt start address
Interrupt is generated. ( INT xx)
Request flag (IRQx) <-- 1
IEx = 1 ?
YES
Generates the corresponding vector
interrupt and releases power down
IME = 1 ?
YES
YES
IS1,0 = 0, 0 ?
NO
IS1,0 = 0, 1 ?
YES
High priority interrupt ?
YES
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
Figure 7-1. Interrupt Execution Flowchart
NO
Retains value until IEx =1
NO
Retains value until IME =1
Retains until interrupt service
NO
NO
YES
IRQx flag value remains 1
Jump to interrupt start address
Verify interrupt source and clear
IRQx with a BTSTZ instruction
INTERRUPTS
routine is completed.
7-3