Chapter 1 Introduction
MPC5602P Microcontroller Reference Manual, Rev. 4
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Freescale Semiconductor
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Typical SRAM access time: no wait-state for reads and 32-bit writes; 1 wait-state for 8- and 16-bit
writes if back-to-back with a read to same memory block
1.6.6
Interrupt controller (INTC)
The interrupt controller (INTC) provides priority-based preemptive scheduling of interrupt requests,
suitable for statically scheduled hard real-time systems. The INTC handles 128 selectable-priority
interrupt sources.
For high-priority interrupt requests, the time from the assertion of the interrupt request by the peripheral
to the execution of the interrupt service routine (ISR) by the processor has been minimized. The INTC
provides a unique vector for each interrupt request source for quick determination of which ISR has to be
executed. It also provides a wide number of priorities so that lower priority ISRs do not delay the execution
of higher priority ISRs. To allow the appropriate priorities for each source of interrupt request, the priority
of each interrupt request is software configurable.
When multiple tasks share a resource, coherent accesses to that resource need to be supported. The INTC
supports the priority ceiling protocol (PCP) for coherent accesses. By providing a modifiable priority
mask, the priority can be raised temporarily so that all tasks which share the same resource can not preempt
each other.
The INTC provides the following features:
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Unique 9-bit vector for each separate interrupt source
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8 software triggerable interrupt sources
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16 priority levels with fixed hardware arbitration within priority levels for each interrupt source
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Ability to modify the ISR or task priority: modifying the priority can be used to implement the
priority ceiling protocol for accessing shared resources.
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1 external high priority interrupt (NMI) directly accessing the main core and I/O processor (IOP)
critical interrupt mechanism
1.6.7
System status and configuration module (SSCM)
The system status and configuration module (SSCM) provides central device functionality.
The SSCM includes these features:
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System configuration and status
— Memory sizes/status
— Device mode and security status
— Determine boot vector
— Search code flash for bootable sector
— DMA status
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Debug status port enable and selection
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Bus and peripheral abort enable/disable