MPC555
/
MPC556
SYSTEM CONFIGURATION AND PROTECTION
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
6-11
.
Figure 6-5 MPC555
/
MPC556 Interrupt Configuration
6.4.1 SIU Interrupt Sources Priority
The SIU has 15 interrupt sources that assert just one interrupt request to the RCPU.
There are eight external IRQ pins (IRQ[0] should be masked since it generates a NMI)
and eight interrupt levels. The priority between all interrupt sources is shown in
SIPEND
SIMASK
Interrupt Request
S
I
V
E
C
Priority
Interrupt
Detector
8
IRQ[0]
Interrupt Vector
NMI to RCPU
(to RCPU and Pads)
Interrupt Level (0-7)
IRQ[0:7]
latch
(1 from 16)
Highest
(Enables Branch
to the Highest Priority
Interrupt Routine)
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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