Interrupt Control Modes And Interrupt Operation - Renesas H8S Family Hardware Manual

5.6

Interrupt Control Modes and Interrupt Operation

The interrupt controller has two modes: Interrupt control mode 0 and interrupt control mode 1.
Interrupt operations differ depending on the interrupt control mode. NMI interrupts and address
break interrupts are always accepted except for in reset state or in hardware standby mode. The
interrupt control mode is selected by SYSCR. Table 5.4 shows the interrupt control modes.
Table 5.4 Interrupt Control Modes
Interrupt SYSCR
Control
Mode INTM1
0 0
1
Figure 5.3 shows a block diagram of the priority decision circuit.
Interrupt
source
Figure 5.3 Block Diagram of Interrupt Control Operation
Priority
Setting
INTM0 Registers
0 ICR
1 ICR
I
ICR
Interrupt
acceptance control
and 3-level mask
control
Interrupt control modes
0 and 1
Interrupt
Mask Bits Description
I Interrupt mask control is performed by
the I bit. Priority levels can be set with
ICR.
I, UI 3-level interrupt mask control is
performed by the I and UI bits. Priority
levels can be set with ICR.
UI
Default priority
determination
Rev. 1.00 Mar. 12, 2008 Page 91 of 1178
Section 5 Interrupt Controller
Vector
number
REJ09B0403-0100