Description

Lock the write bulk pipe.

Files

usbd_phdc_os.h / usbd_phdc_os.c

Prototype

void  USBD_PHDC_OS_WrBulkLock (CPU_INT08U   class_nbr,
                               CPU_INT08U   prio,
                               CPU_INT16U   timeout,
                               USBD_ERR    *p_err);

Arguments

class_nbr

PHDC instance number.

prio

Priority of the transfer. This value is between 0 and 4 and is computed in function of the transfer’s QoS by the caller.

timeout

Timeout.

p_err

Pointer to variable that will receive the return error code from this function.

Returned Value

None.

Callers

Personal Healthcare Device Class.

Implementation guidelines

1. Two typical implementations will be possible here. The first one consists in pending on a semaphore that locks the write bulk pipe, just as we saw previously.
2. But since different QoS data can travel using a single bulk IN endpoint, you might want to prioritize them in function of the QoS. See PHDC RTOS QoS-based scheduler for more details on how a priority manager can be implemented.
3. p_err argument should be assigned as described in Table - Error Code Assignment in Function of Lock Operation Result.