Freescale Semiconductor MPC5553 - Page 373

MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
10-4 Freescale Semiconductor
the vector of the interrupt request source. Typical program flow for software vector mode is shown in
Figure 10-4.
Figure 10-4. Program Flow—Software Vector Mode
In hardware vector mode, the e200z6 branches to a unique interrupt exception handler whose location is
unique for each interrupt request source. Typical program flow for hardware vector mode is shown in
Figure 10-5.
Figure 10-5. Program Flow—Hardware Vector Mode
For high priority interrupt requests in these target applications, the time from the assertion of the interrupt
request from the peripheral to when the processor is performing useful work to service the interrupt request
needs to be minimized. The INTC may be optimized to support this goal through the hardware vector
mode, where a unique vector is provided for each interrupt request source. It also provides 16 priorities so
that lower priority ISRs do not delay the execution of higher priority ISRs. Because each individual
application will have different priorities for each source of interrupt request, the priority of each interrupt
request is configurable.
When multiple tasks share a resource, coherent accesses to that resource need to be supported. The INTC
supports the priority ceiling protocol for coherent accesses. By providing a modifiable priority mask, the
ISR
NOTES:
1 The number of interrupt sources in the
ISR_0 address ISR_0
ISRISR_1
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•
•
ISR
ISR_n
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•
•
ISR
ISR_3071
ISR_n address
ISR_307 address
ISR_1 address
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Prolog
(Including
Using IACKR
to get Vector
then bl ISR_n
Epilog
IVPR + IVOR4
IRQn
Take n
IACKR
InstructionsAddressInstructionsAddress
MPC5553 is 210, which includes 13 reserved.
VTBA
Prologb handler_0 handler_0
ISR
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ISR
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Instructions
NOTE:
‘b ISR_n’ is technically part of the handler.
Epilog
Prolog
Epilog
ISR
Prolog
Epilog
handler_n
handler_307
b handler_1
•
•
•
b handler_2
•
•
•
b handler_n
b handler_307
IVPR + 0x00
IVPR + 0x10
IVPR + 0x20
IVPR + n[0x10]
IVPR + 0x1330
IRQn
Take n
Address