Renesas 70 用户手册

下载
页码 162
Chapter 7 Application Creation Guide 
   
- 136 - 
7.1  Processing Procedures for System Calls from Handlers 
When a service call is issued from a handler, task switching does not occur unlike in the case of a service call 
from a task. However, task switching occurs when a return from a handler
 is made. 
The processing procedures for service calls from handlers are roughly classified into the following three types. 
1.  A service call from a handler that caused an interrupt during task execution 
2.  A service call from a handler that caused an interrupt during service call processing 
3.  A service call from a handler that caused an interrupt (multiplex interrupt) during handler exe-
cution 
                                                      
62
  The service call can't be issued from OS-independent handler. Therefore, The handler described here does not include the 
OS-independent handler.