Chapter 7 Application Creation Guide
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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 62 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.