M32C84 Datasheet, PDF (131/529 Pages) Renesas Technology Corp – 16/32-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M32C/80 SERIES

M32C/84 Group (M32C/84, M32C/84T)
11. Interrupts
11.4 High-Speed Interrupt
The high-speed interrupt executes an interrupt sequence in five cycles and returns from the interrupt in
three cycles.
When the FSIT bit in the RLVL register is set to "1" (interrupt priority level 7 available for the high-speed
interrupt), the ILVL2 to ILVL0 bits in the interrupt control registers can be set to "1112" (level 7) to use the
high-speed interrupt.
Only one interrupt can be set as the high-speed interrupt. When using the high-speed interrupt, do not set
multiple interrupts to interrupt priority level 7. Set the DMAII bit in the RLVL register to "0" (interrupt priority
level 7 available for interrupts).
Set the starting address of the high-speed interrupt routine in the VCT register.
When the high-speed interrupt is acknowledged, the FLG register is saved into the SVF register and PC is
saved into the SVP register. The program is executed from an address indicated by the VCT register.
Execute the FREIT instruction to return from the high-speed interrupt routine.
The values saved into the SVF and SVP registers are restored to the FLG register and PC by executing the
FREIT instruction.
The high-speed interrupt and the DMA2 and DMA3 use the same register. When using the high-speed
interrupt, neither DMA2 nor DMA3 is available. DMA0 and DMA1 can be used.
11.5 Interrupts and Interrupt Vectors
There are four bytes in one vector. Set the starting address of interrupt routine in each vector table. When
an interrupt request is acknowledged, the interrupt routine is executed from the address set in the interrupt
vectors.
Figure 11.2 shows the interrupt vector.
MSB
LSB
Vector Address + 0 Low-order bits of an address
Vector Address + 1 ^{Middle-order bits of an address}
Vector Address + 2
Vector Address + 3
High-order bits of an address
0 0 16
Figure 11.2 Interrupt Vector
Rev. 1.01 Jul. 07, 2005 Page 110 of 495
REJ09B0036-0101