Renesas 70 Manual De Usuario

   

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Interrupt enable/disable control in a service call is accomplished by IPL manipulation. The IPL value in a service 
call is set to the kernel mask level(OS interrupt disable level = system.IPL) in order to disable interrupts for the 
kernel(OS-dependent) interrupt handler. In sections where all interrupts can be enabled, it is returned to the ini-
tial IPL value when the service call was invoked.   

  shows the interrupt enable flag and IPL status in a service call. 

 

• 

For service calls that can be issued from only task context. 

Task 

Service call issued 

Service call processing

I flag 

IPL 

1 

0 

system.IPL

system.IPL 

1 

0 

0 

1 

0 

Task 

Service call issued 

Service call processing 

I flag 

IPL 

0 

0 

system.IPL

system.IPL 

1 

0 

0 

0 

0 

When the I flag before issuing a service call is 1. 

When the I flag before issuing a service call is 0. 

 

• 

For service calls that can be issued from only non-task context or from both task context and non-task 
context.