Forum Post: RE: USBX CDC ACM Host

To use the USB host on the S3A7 make sure the USBF DIP switch on the Top board in Off. Then to register the USBFS peripheral as a host controller :- #include "ux_api.h" #include "ux_host_class_cdc_acm.h" #include "ux_hcd_synergy.h"    /* Initialize USBX. Memory */    ux_system_initialize((CHAR *) g_usb_memory, sizeof(g_usb_memory), UX_NULL, 0);    /* The code below is required for installing the host portion of USBX */    status =  ux_host_stack_initialize(demo_host_change_function);    if (status != UX_SUCCESS)    {        return;    }    /* Register all the host class drivers for this USBX implementation.  */    status =  ux_host_stack_class_register(_ux_system_host_class_cdc_acm_name, _ux_host_class_cdc_acm_entry);    if (status != UX_SUCCESS)    {        return;    }    /* Register all the USB host controllers available in this system */    status =  ux_host_stack_hcd_register((UCHAR *)"DK-S3A7", _ux_hcd_synergy_initialize, R_USBFS_BASE, UX_SYNERGY_CONTROLLER_S3A7);    if (status != UX_SUCCESS)    {        return;    }    /* Port 4_7 needs to be high to enable USB VBUS */    g_ioport.p_api- pinCfg(IOPORT_PORT_04_PIN_07, IOPORT_CFG_PORT_DIRECTION_OUTPUT);    g_ioport.p_api- pinWrite(IOPORT_PORT_04_PIN_07, IOPORT_LEVEL_HIGH); Then the host change function (this is registered with the host stack in the call ux_host_stack_initialize(demo_host_change_function); ), which notifies you of a USB change (insertion or removal) is :- UINT demo_host_change_function(ULONG event, UX_HOST_CLASS * class, VOID * instance) { UINT            status; UX_HOST_CLASS   *cdc_acm_host_class;     /* Check if there is a device insertion.  */     if (UX_DEVICE_INSERTION == event)     {         /* Get the storage class.  */         status = ux_host_stack_class_get(_ux_system_host_class_cdc_acm_name, &cdc_acm_host_class);         if (UX_SUCCESS != status)         {             return(status);         }         /* Check if we got a CDC ACM class device.  */         if (cdc_acm_host_class == class)         {             g_cdc_acm = (UX_HOST_CLASS_CDC_ACM *) instance;         }     }     /* Check if some device is removed.  */     else if(UX_DEVICE_REMOVAL == event)     {         g_cdc_acm = (UX_HOST_CLASS_CDC_ACM *) NULL;     }     else     {         /* Default case, nothing to do */     }     return(UX_SUCCESS); } Then to use the CDC ACM, e.g. for a write :-         if (NULL != g_cdc_acm)         {             status = ux_host_class_cdc_acm_write(g_cdc_acm, (UCHAR *)&message, length, &actual_length);             if (UX_SUCCESS != status)             {                 while(1);             }         }