USBD_PHDC_CfgAdd

Description

Add a PHDC instance into the specified configuration. The PHDC instance was previously created by the function USBD_PHDC_Add.

Files

usbd_phdc.h / usbd_phdc.c

Prototype

void  USBD_PHDC_CfgAdd (CPU_INT08U   class_nbr,
                        CPU_INT08U   dev_nbr,
                        CPU_INT08U   cfg_nbr,
                        USBD_ERR    *p_err);

Arguments

class_nbr

PHDC instance number.

dev_nbr

Device number.

cfg_nbr

Configuration index to add PHDC instance to.

p_err

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

USBD_ERR_NONE

USBD_ERR_INVALID_ARG

USBD_ERR_ALLOC

USBD_ERR_NULL_PTR

USBD_ERR_DEV_INVALID_NBR

USBD_ERR_DEV_INVALID_STATE

USBD_ERR_CFG_INVALID_NBR

USBD_ERR_IF_ALLOC

USBD_ERR_IF_ALT_ALLOC

USBD_ERR_IF_INVALID_NBR

USBD_ERR_EP_NONE_AVAIL

USBD_ERR_EP_ALLOC

Returned Value

None.

Callers

Application.

Notes / Warnings

USBD_PHDC_CfgAdd() basically adds an Interface descriptor and its associated Endpoint descriptor(s) to the Configuration descriptor. One call to USBD_PHDC_CfgAdd() builds the Configuration descriptor corresponding to a PHDC device with the following format:
```
Configuration Descriptor
```
```
|-- Interface Descriptor (PHDC)
```
```
    |-- Endpoint Descriptor (Bulk OUT)
```
```
    |-- Endpoint Descriptor (Bulk IN)
```
```
    |-- Endpoint Descriptor (Interrupt IN) - optional
```
The Interrupt IN endpoint is optional. It will be added to the Interface descriptor if application specified that it will send low latency data when calling USBD_PHDC_WrCfg().
If USBD_PHDC_CfgAdd() is called several times from the application, it allows to create multiple instances and multiple configurations. For instance, the following architecture could be created for an high-speed device:
```
High-speed
```
```
|-- Configuration 0
```
```
    |-- Interface 0 (PHDC 0)
```
```
|-- Configuration 1
```
```
    |-- Interface 0 (PHDC 0)
```
```
    |-- Interface 1 (PHDC 1)
```
In that example, there are two instances of PHDC: 'PHDC 0' and 'PHDC 1', and two possible configurations for the device: 'Configuration 0' and 'Configuration 1'. 'Configuration 1' is composed of two interfaces. Each class instance has an association with one of the interfaces. If 'Configuration 1' is activated by the host, it allows the host to access two different functionalities offered by the device.