IPC@CHIP Documentation - SC12 @CHIP-RTOS V1.10

Comments
Use this function to either surrender access to a counting semaphore, or to indicate that some resource
guarded by this semaphore has become available.
Upon this signal, the semaphore will be given to the task (if any) which is waiting at the head of this
semaphore's wait queue. This can result in an immediate task switch if this waiting task is higher
priority than the calling task.
This function must not be called for resource semaphores, as this will cause the resource semaphore to
malfunction.
Related Topics
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RTX_WAIT_SEM Wait for counting semaphore access
RTX_GET_SEM Get counting semaphore without waiting
RTOS Semaphore Services
Interrupt 0xAD service 0x1B: RTX_WAIT_SEM, Wait on a counting semaphore
Parameters
AH
BX
ES:DI
Wait up to a specified time for access to a counting semaphore.
0x1B (= RTX_WAIT_SEM)
ID of the semaphore acquired from RTX_CREATE_SEM
Pointer to signed long buffer containing the timeout in milliseconds
if timeout == 0, the caller waits forever for the resource
if timeout < 0, value is illegal resulting in error code -48
Return Value
Comments
DX =0 success AX: 0
DX!=0 failure AX: contains error code
This call waits for a defined time to acquire a counting semaphore and returns with an error code -27 if
the semaphore is still not available after the timeout period expires.
The callers wait in FIFO order for the semaphore.
Related Topics
RTX_SIGNAL_SEM Signal counting semaphore
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