Outline

Lock the CPU.

C format

ER loc_cpu ( void ); ER iloc_cpu ( void );

Assembly format

CALL !!_loc_cpu CALL !!_iloc_cpu

Parameter(s)

None.

Explanation

These service calls change the system status type to the CPU locked state.

As a result, maskable interrupt acknowledgment processing is prohibited during the interval from this service call is issued until unl_cpu or iunl_cpu is issued, and service call issuance is also restricted.

If a maskable interrupt is created during the interval from this service call is issued until unl_cpu or iunl_cpu is issued, the RI78V4 delays transition to the relevant interrupt processing (interrupt handler) until either unl_cpu or iunl_cpu is issued.

The service calls that can be issued in the CPU locked state are limited to the one listed below.

Service Call	Function
loc_cpu, iloc_cpu	Lock the CPU.
unl_cpu, iunl_cpu	Unlock the CPU.
sns_ctx	Reference contexts.
sns_loc	Reference CPU state.
sns_dsp	Reference dispatching state.
sns_dpn	Reference dispatch pending state.

Note 1 The CPU locked state changed by issuing this service call must be cancelled before the processing program that issued this service call ends.

Note 2 This service call does not perform queuing of lock requests. If the system is in the CPU locked state, therefore, no processing is performed but it is not handled as an error.

Note 3 The RI78V4 implements disabling of maskable interrupt acknowledgment bu manipulating the interrupt mask flag register (MKxx) and the in-service priority flag (ISPx) of the program status word (PSW). Therefore, manipulating of these registers from the processing program is prohibited from when this service call is issued until unl_cpu or iunl_cpu is issued.

Return value

Macro	Value	Description
E_OK	0	Normal completion.