Renesas 70 - Manual (Page 91)

Chapter 5 Detailed Applications
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When the I flag before issuing a service call is 1
When the I flag before issuing a service call is 0
Service call issued service call processing
I flag
IPL
1
4 system.IPL system.IPL
1 0
4
1
4
Service call issued service call processing
I flag
IPL
0
4 system.IPL system.IPL
0 0
4
Task or
Handler
Task or
Handler Task or
Handler
Task or
Handler
4
Figure 5.13 Interrupt control in a System Call that can be Issued from a Task-independent
As shown in Figure 5.12 Interrupt control in a System Call that can be Issued from only a Task
and Figure 5.13 Interrupt control in a System Call that can be Issued from a Task-independent
, the interrupt enable flag and IPL change in a service call. For this reason, if you want to disable interrupts in a
user application, Renesas does not recommend using the method for manipulating the interrupt disable flag and
IPL to disable the interrupts.
The following two methods for interrupt control are recommended:
1. Modify the interrupt control register (SFR) for the interrupt you want to be disabled.
2. Use service calls loc_cpu and unl_cpu.
The interrupts that can be controlled by the loc_cpu service call are only the kernel(OS-dependent)
interrupt. Use method 1 to control the non-kernel(OS-independent) interrupts.