MC56F8346 Freescale Semiconductor, Inc, MC56F8346 Datasheet - Page 81

• Manufacturer Part Number: MC56F8346
• Description: 56f8300 16-bit Digital Signal Controllers
• Manufacturer: Freescale Semiconductor, Inc

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.
5.4 Block Diagram
5.5 Operating Modes
The ITCN module design contains two major modes of operation:
Freescale Semiconductor
Preliminary
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
•
Functional Mode
The ITCN is in this mode by default.
INT1
INT82
Decode
Decode
Priority
Priority
Level
Level
2 -> 4
2 -> 4
Figure 5-1 Interrupt Controller Block Diagram
56F8346 Technical Data, Rev. 15
Level 0
Level 3
Encoder
Encoder
Priority
Priority
82 -> 7
82 -> 7
7
7
any0
any3
IACK
SR[9:8]
CONTROL
PIC_EN
INT
VAB
IPIC
Block Diagram
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