USBB17RX78K4-XXX NEC Electronics, USBB17RX78K4-XXX Datasheet - Page 57

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

4.2.7 sig_sem (Signal Semaphore)
48
[Function]
[Remarks]
[System call ID number]
[Parameter]
[Return parameter]
[Assembler format]
[C format]
•
•
•
isig_sem (Signal Semaphore for Interrupt)
Executes signal manipulation for semaphore (V instruction).
If tasks exist that wait for a semaphore indicated by semid, the task at the top of the queue is placed in the
READY state. If no task is waiting for the semaphore, the count value of the semaphore is increased by one.
If the count value of the semaphore is about to exceed the upper limit (0FFH), “E_QOVR” is returned as an
error code.
sig_sem = 16
semid (Semaphore Identifier)
E_OK
E_QOVR
On issuing sig_sem
[Large model]
MOV
MOVW
MOV
CALLT
C register = return parameter
On issuing isig_sem
[Large model]
MOVG
CALLT
C register = return parameter
On issuing sig_sem
ret = sig_sem (semid);
char
bnk0_b, #16
bnk0_d, #semid
[40H]
:
[4AH]
:
*semid;
bnk0_up, #semid
UUP, #semid
CHAPTER 4
•
Semaphore ID (Semaphore top address)
Normal termination
[Small model]
MOV
MOVW
CALLT
C register = return parameter
[Small model]
MOVW
CALLT
C register = return parameter
On issuing isig_sem
ret = isig_sem (semid);
char
Queue overflow
RX78K/IV SYSTEM CALL LIST
bnk0_b, #16
[40H]
:
[4AH]
:
*semid;
bnk0_up, #semid
UP, #semid
- 24 bits (large model)
- 16 bits (small model)