MC56F8323EVM Freescale Semiconductor, MC56F8323EVM Datasheet - Page 58

• Manufacturer Part Number: MC56F8323EVM
• Description: KIT EVALUATION FOR MC56F8323
• Manufacturer: Freescale Semiconductor
• Type: DSPr

Specifications of MC56F8323EVM

• Contents: Module and Misc Hardware
• Processor To Be Evaluated: MC56F8322 and MC56F8323
• Data Bus Width: 16 bit
• Interface Type: RS-232
• For Use With/related Products: MC56F8322, MC56F8323
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

5.3.3
Fast interrupts are described in the DSP56800E Reference Manual. The interrupt controller recognizes
fast interrupts before the core does.
A fast interrupt is defined (to the ITCN) by:
When an interrupt occurs, its vector number is compared with the FIM0 and FIM1 register values. If a
match occurs, and it is a level 2 interrupt, the ITCN handles it as a fast interrupt. The ITCN takes the vector
address from the appropriate FIVALn and FIVAHn registers, instead of generating an address that is an
offset from the VBA.
The core then fetches the instruction from the indicated vector adddress and if it is not a JSR, the core starts
its fast interrupt handling.
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1. Setting the priority of the interrupt as level 2, with the appropriate field in the IPR registers
2. Setting the FIMn register to the appropriate vector number
3. Setting the FIVALn and FIVAHn registers with the address of the code for the fast interrupt
Fast Interrupt Handling
1. See IPIC field definition in Section 5.6.30.2
00
01
10
11
IPIC_LEVEL[1:0]
Table 5-2. Interrupt Priority Encoding
56F8323 Technical Data, Rev. 17
1
No Interrupt or SWILP
Priority 0
Priority 1
Priorities 2 or 3
Current Interrupt
Priority Level
Priorities 0, 1, 2, 3
Priorities 1, 2, 3
Priorities 2, 3
Priority 3
Exception Priority
Required Nested
Freescale Semiconductor
Preliminary