Hardware Interrupt - Fujitsu MB90895 Series Hardware Manual

3.5.5

Hardware Interrupt

The hardware interrupt responds to the interrupt request from a resource, suspends the
current-executing program and transfers control to the interrupt processing program
defined by user.
The hardware interrupt corresponds to the EI
I Hardware Interrupt
G
Function of hardware interrupt
When a hardware interrupt occurs, the interrupt level (IR: IL) of the interrupt request from a peripheral
resource is compared with the interrupt level mask register (PS: ILM) and the state of the interrupt enable
flag (CCR: I) is referenced to determine whether can be accepted.
When the hardware interrupt is accepted, registers in the CPU are automatically saved in the system stack.
The interrupt level of the accepted interrupt is stored in the interrupt level mask register (ILM), then
branches to the corresponding interrupt vector.
G
Multiple interrupts
Multiple hardware interrupts can be started.
G
2
EI OS
When the EI
are not started at once. During EI
hold.
G
External interrupt
The external interrupt (wake-up interrupt included) is accepted as a hardware interrupt via the peripheral
(interrupt request detector).
G
Interrupt Vector
The interrupt vector tables referenced during interrupt processing are allocated to "FFFC00
"FFFFFF
2
OS function ends, normal interrupt processing is performed. Two or more instances of EI
2
OS processing, other interrupt requests and EI
" in the memory and shared with software interrupts.
H
2
OS.
CHAPTER 3 CPU
2
OS
2
OS requests are all put on
" to
H
69