USBB17RX78K4-XXX NEC Electronics, USBB17RX78K4-XXX Datasheet - Page 59

• Manufacturer Part Number: USBB17RX78K4-XXX
• Description: 78K/4 series realtime OS
• Manufacturer: NEC Electronics

4.2.9 preq_sem (Poll and Request Semaphore)
50
[Function]
[Remarks]
[System call ID number]
[Parameter]
[Return parameter]
[Assembler format]
[C format]
Obtains a semaphore resource.
If the count value of the semaphore indicated by semid is 1 or more, the count value of the semaphore is
decremented by one, and the task terminates normally. If the count value of the semaphore is 0, the
semaphore value is not changed and an error is returned (E_PLFAIL).
preq_sem = 18
semid (Semaphore Identifier)
E_OK
E_PLFAIL
[Large model]
MOV
MOVW
MOV
CALLT
C register = return parameter
ret = preq_sem(semid);
char
bnk0_b, #18
bnk0_d, #semid
[40H]
:
*semid;
bnk0_up, #semid
CHAPTER 4
Semaphore ID (Semaphore top address)
Normal termination
Polling failed
[Small model]
MOV
MOVW
CALLT
C register = return parameter
RX78K/IV SYSTEM CALL LIST
bnk0_b, #18
[40H]
bnk0_up, #semid
:
- 24 bits (large model)
- 16 bits (small model)