Content Comparison

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usbd_msc.h / usbd_msc.c

Prototype

CPU_BOOLEAN  USBD_MSC_CfgAdd (CPU_INT08U   class_nbr,
                              CPU_INT08U   dev_nbr,
                              CPU_INT08U   cfg_nbr,
                              USBD_ERR    *p_err);

Arguments

class_nbr

MSC instance number.

...

 |-- Endpoint Descriptor (Bulk IN)

If USBD_MSC_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:

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    |-- Interface 0 (MSC 0)

    |-- Interface 1 (MSC 1) 

In that example, there are two instances of MSC: 'MSC 0' and 'MSC 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.