Outline

Enable dispatching.

C format

 ER      ena_dsp (void);

Parameter(s)

None.

Explanation

This service call transits the system to the dispatching enabled state.

The operation that changes in the dispatching disabled state is as follows.

- dis_dsp

- chg_ims that changes PSW.IPL to other than 0.

The operation that changes in the dispatching enabled state is as follows.

- ena_dsp

- ext_tsk

- exd_tsk

- chg_ims that changes PSW.IPL to 0.

Note 1 This service call does not perform queuing of enable requests. If the system is in the dispatch enabled state, therefore, no processing is performed but it is not handled as an error.

Note 2 If a service call (such as wai_sem, wai_flg) that may move the status of the invoking task is issued from when dis_dsp is issued until this service call is issued, the RI600PX returns E_CTX regardless of whether the required condition is immediately satisfied.

Return value

Macro	Value	Description
E_OK	0	Normal completion.
E_CTX	-25	Context error. - This service call was issued from a non-task. - This service call was issued in the CPU locked state. - This service call was issued in the status "PSW.IPL > kernel interrupt mask level".
E_MACV	-26	Memory access violation. - Stack pointer points out of user stack for invoking task.