MPC555
/
MPC556
SYSTEM CONFIGURATION AND PROTECTION
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
6-9
Figure 6-4 MPC555
/
MPC556 Interrupt Structure
If programmed to generate interrupts, the SWT and external pin IRQ[0] always gener-
ate a non-maskable interrupt (NMI) to the RCPU. Notice that the RCPU takes the sys-
tem reset interrupt when an NMI is asserted and the external interrupt for any other
interrupt asserted by the interrupt controller.
Each one of the external pins IRQ[1:7] has its own dedicated assigned priority level.
IRQ[0] is also mapped but should be used only as a status bit indicating that IRQ[0]
was asserted and generated an NMI interrupt. There are eight additional interrupt pri-
Level 2
Level 7
Level 6
Level 5
Level 4
Level 3
Level 1
Level 0
NMI
IREQ
NMI
Generate
RCPU
SIU
TB
PIT
RTC
Change of Lock
SWT
IRQ0
Int
e
rr
u
p
t Co
ntr
o
ller
DEC
DEC
Debug
Debug
IRQOUT
IRQ[0:7]
Se
lec
tor
Edge
Detect
IMB3
Interrupt
Levels
UIMB
8
8
8
8
8
I0
I1
I2
I3
I4
I5
I6
I7
IRQ[0:6]
→
Level 0:6
IRQ[7:31]
→
Level 7
IMB3 Interrupts:
32
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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