USBD_PHDC_PreambleWr

Description

Write metadata preamble. This function is blocking.

Files

usbd_phdc.h / usbd_phdc.c

Prototype

Arguments

class_nbr

PHDC instance number.

p_data_opaque

Pointer to buffer that will supply opaque data.

data_opaque_len

Length of opaque data buffer in octets.

latency_rely

Latency reliability of related transfers.

nbr_xfers

Number of transfers this preamble will apply to.

timeout

Timeout in milliseconds.

p_err

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

USBD_ERR_NONE

USBD_ERR_INVALID_ARG

USBD_ERR_NULL_PTR

USBD_ERR_TX

USBD_ERR_DEV_INVALID_NBR

USBD_ERR_DEV_INVALID_STATE

USBD_ERR_EP_INVALID_ADDR

USBD_ERR_EP_INVALID_STATE

USBD_ERR_EP_INVALID_TYPE

USBD_OS_ERR_TIMEOUT

USBD_OS_ERR_ABORT

USBD_OS_ERR_FAIL

Returned Value

None.

Callers

Application.

Notes / Warnings

1. USBD_PHDC_PreambleWr() should always be called before USBD_PHDC_Wr() if metadata message preambles are enabled by the host and if the latency of the transfer is not ‘low’.
2. Application will have to call USBD_PHDC_Wr() ‘nbr_xfers’ of times with the same latency / reliability parameter after a call to USBD_PHDC_PreambleWr().