RX610 Group
10. ICU
R01UH0032EJ0120 Rev.1.20
Page 242 of 1006
Feb 20, 2013
10.4
Operation
The interrupt control unit determines priority levels of interrupts and non-maskable interrupts and outputs interrupt
request signals to the CPU, DTC and/or DMAC.
When the condition for the interrupt source is generated, the corresponding interrupt status flag (IR flag in IRi) is set and
interrupt request signal is output to the request destination. For the interrupt request signals to be output to the interrupt
request destination, the setting of the IENj bit in IERi must enable the interrupt. If multiple IR flags in IRi are set to 1 at
the same time, the interrupt request signals from the highest priority sources for the respective interrupt request
destinations are output to the CPU and/or DTC.*
Note: * When multiple interrupt requests that have been set up to activate the DMAC are generated simultaneously, the
priority of the sources is determined by the DMAC.
10.4.1
Enabling and Disabling Interrupts
The following settings are required to enable an interrupt requests.
•
In the case of interrupt requests from peripheral modules, enabling of interrupt output for the corresponding source
by the setting of the interrupt enable bit (or bits) of the peripheral module
•
In the case of external interrupts, enabling of interrupt output in response to signals on the corresponding IRQn pin
by the setting of the IRQEN bit in IRQERn
•
Enabling of the interrupt by the corresponding IENj bit in IERi
When an interrupt signal is generated while output for that interrupt source is enabled at the source for interrupt
generation, the IR flag in the corresponding IRi register will be set.
If the corresponding IENj bit in IERi allows output of the interrupt request, the interrupt request corresponding to the IR
flag in IRi is conveyed to the selected destination. If the IENj bit in IERi has been set to disable the interrupt request, the
interrupt request corresponding to the IR flag in IRi retains the indication that the interrupt signal was generated.
That is, the setting of the IENj bit in IERi does not affect the operation of the IR flag in IRi.