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10.   Interrupt Controller (INTC) 
Rev.1.00  Jan. 10, 2008  Page 327 of 1658 
REJ09B0261-0100 
 
The priority of IRL interrupts should be retained from when an interrupt is accepted to when 
interrupt handling starts. The level can be changed to a higher level. 
When the INTMU bit in CPUOPM is set to 1, the interrupt mask level (IMASK) bit in SR is 
automatically set to the level of the accepted interrupt. When the INTMU bit in CPUOPM is 
cleared to 0, the IMASK bit in SR is not affected. 
When 1 is written to the IRLM0 and IRLM1 bits in ICR0, pins IRQ/
IRL0 to IRQ/IRL3 or 
IRQ/
IRL7 to IRQ/IRL4 can be used for independent IRQ interrupts. For details, see section 
10.4.2, IRQ Interrupts. 
(2)
  Dependence on ICR0.LVLMODE Setting 
(a)
  ICR0.LVLMODE 
= 0 
After an IRL interrupt request is detected, the IRL interrupt with the highest priority is retained in 
the following cases until the CPU accepts an interrupt (including other interrupts). The cases are 
where the interrupt request is withdrawn or where the priority is set lower. 
To clear the retained IRL interrupt source, change the pin state of IRL interrupts by interrupt 
routine and withdraw the interrupt request. The, clear the corresponding interrupt mask bit to 1 
(To clear the IRL interrupt request by pins IRQ/
IRL3 to IRQ/IRL0, write 1 to the IM10 bit in 
INTMSK1. To clear the IRL interrupt request by pins IRQ/
IRL7 to IRQ/IRL4, write 1 to the IM11 
bit in INTMSK1. The IRL interrupt source being detected cannot be cleared even if the masking is 
performed in INTMSK2 by the level.).  
(b)
  ICR0.LVLMODE 
= 1 
The INTC does not retain the IRL interrupt source. 
10.4.4
 
On-Chip Peripheral Module Interrupts 
On-chip module interrupts are interrupts generated in the on-chip modules. 
The interrupt vectors are not allocated to each source, but the source is reflected on INTEVT. 
Therefore, the source can be easily identified by branching the value of INTEVT as offset during 
exception handling routine.  
A priority ranging from 31 to 0 can be set for each module by INT2PRI0 to INT2PRI9. To notify 
the CPU of the priority, round down the least 1-bit and change to 4 bits. For details, see section 
10.4.5, Priority of On-Chip Peripheral Module Interrupts.