SH-2A Datasheet, PDF (39/501 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperH™ RISC engine Family

3.6 Interrupts
Section 3 Exception Handling
3.6.1 Interrupt Sources
Interrupt exception handling can be initiated by an NMI, a user break, the H-UDI, an external
interrupt, or an on-chip peripheral module, as shown in table 3.6.
Table 3.6 Interrupt Sources
Type
NMI
User break
H-UDI
External interrupt (IRQ),
on-chip peripheral module
Request Source
NMI pin (external input)
User break controller
User debug interface
External interrupt pin, on-chip peripheral
module
Number of Sources
1
1
1
See Note
Each interrupt source is assigned a different vector number and vector table offset. For details of
vector numbers and vector table address offsets, see “Interrupt Exception Vectors and Priority” in
the Interrupt Controller section of the hardware manual for the relevant product.
Note: For details and numbers of external interrupts (IRQ) and on-chip peripheral module
request sources, see “Interrupt Sources” in the Interrupt Controller section of the hardware
manual for the relevant product.
3.6.2 Interrupt Priority
Interrupt sources are assigned priority levels. If a number of interrupts occur simultaneously
(multiple interruption), the priority order is determined by the interrupt controller (INTC) and
exception handling is initiated accordingly.
Interrupt source priority levels are expressed as values from 0 to 16, with 0 representing the lowest
priority level and 16 the highest. The NMI interrupt is the highest-priority interrupt at level 16; it
cannot be masked and is always accepted. The user break interrupt and H-UDI are assigned
priority level 15. The priority level of IRQ interrupts and on-chip peripheral module interrupts can
be set as desired in the interrupt priority level setting registers of the INTC (see table 3.7). Priority
levels 0 to 15, but not 16, can be set. For details of the interrupt priority level setting registers, see
the Interrupt Controller section of the hardware manual for the relevant product.
Rev. 3.00 Jul 08, 2005 page 25 of 484
REJ09B0051-0300