FUJITSU MB91F109 FR30 - Manual (Page 82)

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CHAPTER 2 CPU
2.8.4 Interrupt Stack
The interrupt stack is the area indicated by the system stack pointer (SSP). The PC or
PS value is saved to it or restored from it. After an interrupt is caused, the PC value is
stored at the address indicated by the SSP and the PS value is stored at the address
"SSP + 4."
■ Interrupt Stack
Figure 2.8.1 shows an example of the interrupt stack.
Figure 2.8-1 Example of Interrupt Stack
80000000
H
7FFFFFF8
H
80000000
H
80000000
H
7FFFFFFC
H
7FFFFFFC
H
7FFFFFF8
H
7FFFFFF8
H
SSP SSP
Memory Memory
[Before interrupt] [After interrupt]
P
P
S
C