HD6417021 Hitachi Semiconductor, HD6417021 Datasheet - Page 82

• Manufacturer Part Number: HD6417021
• Description: SuperH RISC engine
• Manufacturer: Hitachi Semiconductor

5.2.5
Interrupt Exception Vectors and Priority Rankings
Table 5.3 lists the vector numbers, vector table address offsets, and interrupt priority order of the
interrupt sources.
Each interrupt source is allocated a different vector number and vector table address offset. The
vector table address is calculated from this vector number and address offset. In interrupt
exception processing, the exception service routine start address is fetched from the vector table
indicated by this vector table address. See table 4.3, Calculation of Exception Vector table
Addresses, in section 4, Exception Processing, for details on this calculation.
Arbitrary interrupt priority levels between 0 and 15 can be assigned to IRQ and on-chip peripheral
module interrupt sources by setting interrupt priority registers A–E (IPRA–IPRE) for each pin or
module. The interrupt sources for IPRC–IPRE, however, must be ranked in the order listed under
Priority Within Module in table 5.3 and cannot be changed. A reset assigns priority level 0 to IRQ
and on-chip peripheral module interrupts. If the same priority level is assigned to two or more
interrupt sources, and interrupts from those sources occur simultaneously, their priority order is
the default priority order indicated at the right in table 5.3.
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