SH7243 datasheet(139/1726 Pages) RENESAS

139 / 1726 page

Section 5 Exception Handling

Rev. 1.00 Jun. 26, 2008 Page 109 of 1692

REJ09B0393-0100

5.5.2

Interrupt Priority Level

The interrupt priority order is predetermined. When multiple interrupts occur simultaneously

(overlap), the interrupt controller (INTC) determines their relative priorities and starts processing

according to the results.

The priority order of interrupts is expressed as priority levels 0 to 16, with priority 0 the lowest

and priority 16 the highest. The NMI interrupt has priority 16 and cannot be masked, so it is

always accepted. The user break interrupt and H-UDI interrupt priority level is 15. Priority levels

of IRQ interrupts, and on-chip peripheral module interrupts can be set freely using the interrupt

priority registers 01, 02, and 05 to 18 (IPR01, IPR02, and IPR05 to IPR18) of the INTC as shown

in table 5.8. The priority levels that can be set are 0 to 15. Level 16 cannot be set. See section

6.3.1, Interrupt Priority Registers 01, 02, 05 to 18 (IPR01, IPR02, IPR05 to IPR18), for details of

IPR01, IPR02, and IPR05 to IPR18.

Table 5.8

Interrupt Priority Order

Type

Priority Level

Comment

NMI

Fixed priority level. Cannot be masked.

User break

Fixed priority level.

H-UDI

Fixed priority level.

IRQ

On-chip peripheral module

0 to 15

Set with interrupt priority registers 01, 02, and 05

to 18 (IPR01, IPR02, and IPR05 to IPR18).

SH7243 Datasheet(PDF) 139 Page - Renesas Technology Corp