9.1 原理圖分析

查看EK-RA6M4的原理圖，如下圖所示，該開發板上的 J11 提供了 Micro USB0接口。

根據原理圖可知，USB接口的引腳分別為：

9.2 USB接口配置

首先，在FSP配置中將配置相關管腳為USB外設模式。

然后配置使能USB的48MHz時鐘。

接著選擇 Stacks ，點擊 "New Stack" -> "Connectivity" -> "USB PCDC(r_usb_pcdc)" 添加 USB CDC 協議棧。

接下來設置USB CDC的相關配置，并重新生成代碼。

9.3 源碼修改

創建按鍵操作相關的頭文件 src/r_usb_pcdc_descriptor.c ，該文件從瑞薩EK-RA6M4開發板的示例工程 ek_ra6m4\\usb_pcdc\\usb_pcdc_ek_ra6m4_ep 中拷貝過來。

/***********************************************************************************************************************
 * File Name    : r_usb_pcdc_descriptor.c
 * Description  : USB PCDC Descriptor definition.
 **********************************************************************************************************************/
/***********************************************************************************************************************
 * DISCLAIMER
 * This software is supplied by Renesas Electronics Corporation and is only intended for use with Renesas products. No
 * other uses are authorized. This software is owned by Renesas Electronics Corporation and is protected under all
 * applicable laws, including copyright laws.
 * THIS SOFTWARE IS PROVIDED "AS IS" AND RENESAS MAKES NO WARRANTIES REGARDING
 * THIS SOFTWARE, WHETHER EXPRESS, IMPLIED OR STATUTORY, INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. ALL SUCH WARRANTIES ARE EXPRESSLY DISCLAIMED. TO THE MAXIMUM
 * EXTENT PERMITTED NOT PROHIBITED BY LAW, NEITHER RENESAS ELECTRONICS CORPORATION NOR ANY OF ITS AFFILIATED COMPANIES
 * SHALL BE LIABLE FOR ANY DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES FOR ANY REASON RELATED TO THIS
 * SOFTWARE, EVEN IF RENESAS OR ITS AFFILIATES HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * Renesas reserves the right, without notice, to make changes to this software and to discontinue the availability of
 * this software. By using this software, you agree to the additional terms and conditions found by accessing the
 * following link:
 * http://www.renesas.com/disclaimer
 *
 * Copyright (C) 2020 Renesas Electronics Corporation. All rights reserved.
 ***********************************************************************************************************************/

/******************************************************************************
 Includes   <System Includes> , "Project Includes"
 ******************************************************************************/
#include <r_usb_basic.h>
#include <r_usb_basic_api.h>
#include "r_usb_basic_cfg.h"

/******************************************************************************
 Macro definitions
 ******************************************************************************/
/* bcdUSB */
#define USB_BCDNUM                      (0x0200U)
/* Release Number */
#define USB_RELEASE                     (0x0200U)
/* DCP max packet size */
#define USB_DCPMAXP                     (64U)
/* Configuration number */
#define USB_CONFIGNUM                   (1U)
/* Vendor ID */
#define USB_VENDORID                    (0x045BU)
/* Product ID */
#define USB_PRODUCTID                   (0x5310U)

/* Class-Specific Configuration Descriptors */
#define     USB_PCDC_CS_INTERFACE                               (0x24U)

/* bDescriptor SubType in Communications Class Functional Descriptors */
/* Header Functional Descriptor */
#define     USB_PCDC_DT_SUBTYPE_HEADER_FUNC                     (0x00U)
/* Call Management Functional Descriptor. */
#define     USB_PCDC_DT_SUBTYPE_CALL_MANAGE_FUNC                (0x01U)
/* Abstract Control Management Functional Descriptor. */
#define     USB_PCDC_DT_SUBTYPE_ABSTRACT_CTR_MANAGE_FUNC        (0x02U)
/* Union Functional Descriptor */
#define     USB_PCDC_DT_SUBTYPE_UNION_FUNC                      (0x06U)

/* Communications Class Subclass Codes */
#define     USB_PCDC_CLASS_SUBCLASS_CODE_ABS_CTR_MDL            (0x02U)

/* USB Class Definitions for Communications Devices Specification
 release number in binary-coded decimal. */
#define     USB_PCDC_BCD_CDC          (0x0110U)

/* Descriptor length */
#define USB_PCDC_QD_LEN               (10U)
#define USB_PCDC_CD1_LEN              (67U)
#define STRING_DESCRIPTOR0_LEN        (4U)
#define STRING_DESCRIPTOR1_LEN        (16U)
#define STRING_DESCRIPTOR2_LEN        (44U)
#define STRING_DESCRIPTOR3_LEN        (46U)
#define STRING_DESCRIPTOR4_LEN        (22U)
#define STRING_DESCRIPTOR5_LEN        (18U)
#define STRING_DESCRIPTOR6_LEN        (28U)

/* Descriptor data Mask */
#define USB_UCHAR_MAX                 (0xffU)
#define USB_W_TOTAL_LENGTH_MASK       (256U)
#define USB_W_MAX_PACKET_SIZE_MASK    (64U)
#define USB_PCDC_BCD_CDC_MASK         (256U)

/******************************************************************************
 Private global variables and functions
 ******************************************************************************/

/******************************************************************************
 Exported global variables
 ******************************************************************************/

/******************************************************************************
 Exported global functions (to be accessed by other files)
 ******************************************************************************/

/* Standard Device Descriptor */
uint8_t g_apl_device[USB_DD_BLENGTH + ( USB_DD_BLENGTH % 2)] =
{
    USB_DD_BLENGTH,                                     /*  0:bLength */
    USB_DT_DEVICE,                                      /*  1:bDescriptorType */
    (USB_BCDNUM & (uint8_t) USB_UCHAR_MAX),                     /*  2:bcdUSB_lo */
    ((uint8_t) (USB_BCDNUM >> 8) & (uint8_t) USB_UCHAR_MAX),    /*  3:bcdUSB_hi */
    USB_IFCLS_CDCC,                                     /*  4:bDeviceClass */
    0,                                                  /*  5:bDeviceSubClass */
    0,                                                  /*  6:bDeviceProtocol */
    (uint8_t) USB_DCPMAXP,                              /*  7:bMAXPacketSize(for DCP) */
    (USB_VENDORID & (uint8_t) USB_UCHAR_MAX),                   /*  8:idVendor_lo */
    ((uint8_t) (USB_VENDORID >> 8) & (uint8_t) USB_UCHAR_MAX),  /*  9:idVendor_hi */
    ((uint16_t) USB_PRODUCTID & (uint8_t) USB_UCHAR_MAX),       /* 10:idProduct_lo */
    ((uint8_t) (USB_PRODUCTID >> 8) & (uint8_t) USB_UCHAR_MAX), /* 11:idProduct_hi */
    (USB_RELEASE & (uint8_t) USB_UCHAR_MAX),                    /* 12:bcdDevice_lo */
    ((uint8_t) (USB_RELEASE >> 8) & (uint8_t) USB_UCHAR_MAX),   /* 13:bcdDevice_hi */
    1,                                                  /* 14:iManufacturer */
    2,                                                  /* 15:iProduct */
    6,                                                  /* 16:iSerialNumber */
    USB_CONFIGNUM /* 17:bNumConfigurations */
};

/************************************************************
 *  Device Qualifier Descriptor   *
 ************************************************************/
uint8_t g_apl_qualifier_descriptor[USB_PCDC_QD_LEN + ( USB_PCDC_QD_LEN % 2)] =
{
    USB_PCDC_QD_LEN,                                    /*  0:bLength */
    USB_DT_DEVICE_QUALIFIER,                            /*  1:bDescriptorType */
    (USB_BCDNUM & (uint8_t) USB_UCHAR_MAX),                  /*  2:bcdUSB_lo */
    ((uint8_t) (USB_BCDNUM >> 8) & (uint8_t) USB_UCHAR_MAX), /*  3:bcdUSB_hi */
    0,                                                  /*  4:bDeviceClass */
    0,                                                  /*  5:bDeviceSubClass */
    0,                                                  /*  6:bDeviceProtocol */
    (uint8_t) USB_DCPMAXP,                              /*  7:bMAXPacketSize(for DCP) */
    USB_CONFIGNUM,                                      /*  8:bNumConfigurations */
    0 /*  9:bReserved */
};

/************************************************************
 *  Configuration Or Other_Speed_Configuration Descriptor   *
 ************************************************************/
/* For Full-Speed */
uint8_t g_apl_configuration[USB_PCDC_CD1_LEN + ( USB_PCDC_CD1_LEN % 2)] =
{
    USB_CD_BLENGTH,                 /*  0:bLength */
    USB_SOFT_CHANGE,                /*  1:bDescriptorType */
    USB_PCDC_CD1_LEN % USB_W_TOTAL_LENGTH_MASK, /*  2:wTotalLength(L) */
    USB_PCDC_CD1_LEN / USB_W_TOTAL_LENGTH_MASK, /*  3:wTotalLength(H) */
    2,                              /*  4:bNumInterfaces */
    1,                              /*  5:bConfigurationValue */
    0,                              /*  6:iConfiguration */
    USB_CF_RESERVED | USB_CF_SELFP, /*  7:bmAttributes */
    (10 / 2),                       /*  8:MAXPower (2mA unit) */

    /* Interface Descriptor */
    USB_ID_BLENGTH,                 /*  0:bLength */
    USB_DT_INTERFACE,               /*  1:bDescriptor */
    0,                              /*  2:bInterfaceNumber */
    0,                              /*  3:bAlternateSetting */
    1,                              /*  4:bNumEndpoints */
    USB_IFCLS_CDCC,                 /*  5:bInterfaceClass */
    USB_PCDC_CLASS_SUBCLASS_CODE_ABS_CTR_MDL,   /*  6:bInterfaceSubClass */
    1,                              /*  7:bInterfaceProtocol */
    0,                              /*  8:iInterface */

        /* Communications Class Functional Descriptorss */
        5,                          /*  0:bLength */
        USB_PCDC_CS_INTERFACE,      /*  1:bDescriptorType */
        USB_PCDC_DT_SUBTYPE_HEADER_FUNC,    /*  2:bDescriptorSubtype */
        USB_PCDC_BCD_CDC % USB_W_TOTAL_LENGTH_MASK,     /*  3:bcdCDC_lo */
        USB_PCDC_BCD_CDC / USB_W_TOTAL_LENGTH_MASK,     /*  4:bcdCDC_hi */

        /* Communications Class Functional Descriptorss */
        4,                          /*  0:bLength */
        USB_PCDC_CS_INTERFACE,      /*  1:bDescriptorType */
        USB_PCDC_DT_SUBTYPE_ABSTRACT_CTR_MANAGE_FUNC,   /*  2:bDescriptorSubtype */
        2,                          /*  3:bmCapabilities */

        /* Communications Class Functional Descriptorss */
        5,                          /*  0:bLength */
        USB_PCDC_CS_INTERFACE,      /*  1:bDescriptorType */
        USB_PCDC_DT_SUBTYPE_UNION_FUNC, /*  2:bDescriptorSubtype */
        0,                          /*  3:bMasterInterface */
        1,                          /*  4:bSlaveInterface0 */

        /* Communications Class Functional Descriptorss */
        5,                          /*  0:bLength */
        USB_PCDC_CS_INTERFACE,      /*  1:bDescriptorType */
        USB_PCDC_DT_SUBTYPE_CALL_MANAGE_FUNC,   /*  2:bDescriptorSubtype */
        /* D1:1-Device can send/receive call management
         information over a Data Class interface. */
        /* D0:1-Device handles call management itself. */
        3,                          /*  3:bmCapabilities */
        1,                          /*  4:bDataInterface */

        /* Endpoint Descriptor 0 */
        7,                          /*  0:bLength */
        USB_DT_ENDPOINT,            /*  1:bDescriptorType */
        USB_EP_IN | USB_EP3,        /*  2:bEndpointAddress */
        USB_EP_INT,                 /*  3:bmAttribute */
        16,                         /*  4:wMAXPacketSize_lo */
        0,                          /*  5:wMAXPacketSize_hi */
        0x10,                       /*  6:bInterval */

    /* Interface Descriptor */
    USB_ID_BLENGTH,                 /*  0:bLength */
    USB_DT_INTERFACE,               /*  1:bDescriptor */
    1,                              /*  2:bInterfaceNumber */
    0,                              /*  3:bAlternateSetting */
    2,                              /*  4:bNumEndpoints */
    USB_IFCLS_CDCD,                 /*  5:bInterfaceClass */
    0,                              /*  6:bInterfaceSubClass */
    0,                              /*  7:bInterfaceProtocol */
    0,                              /*  8:iInterface */

        /* Endpoint Descriptor 0 */
        USB_ED_BLENGTH,             /*  0:bLength */
        USB_DT_ENDPOINT,            /*  1:bDescriptorType */
        USB_EP_IN | USB_EP1,        /*  2:bEndpointAddress */
        USB_EP_BULK,                /*  3:bmAttribute */
        USB_W_MAX_PACKET_SIZE_MASK, /*  4:wMAXPacketSize_lo */
        0,                          /*  5:wMAXPacketSize_hi */
        0,                          /*  6:bInterval */

        /* Endpoint Descriptor 1 */
        USB_ED_BLENGTH,             /*  0:bLength */
        USB_DT_ENDPOINT,            /*  1:bDescriptorType */
        USB_EP_OUT | USB_EP2,       /*  2:bEndpointAddress */
        USB_EP_BULK,                /*  3:bmAttribute */
        USB_W_MAX_PACKET_SIZE_MASK, /*  4:wMAXPacketSize_lo */
        0,                          /*  5:wMAXPacketSize_hi */
        0,                          /*  6:bInterval */
};

/* For High-Speed */
uint8_t g_apl_hs_configuration[USB_PCDC_CD1_LEN + ( USB_PCDC_CD1_LEN % 2)] =
{
    9,                              /*  0:bLength */
    USB_SOFT_CHANGE,                /*  1:bDescriptorType */
    USB_PCDC_CD1_LEN % USB_W_TOTAL_LENGTH_MASK,         /*  2:wTotalLength(L) */
    USB_PCDC_CD1_LEN / USB_W_TOTAL_LENGTH_MASK,         /*  3:wTotalLength(H) */
    2,                              /*  4:bNumInterfaces */
    1,                              /*  5:bConfigurationValue */
    0,                              /*  6:iConfiguration */
    USB_CF_RESERVED | USB_CF_SELFP, /*  7:bmAttributes */
    (10 / 2),                       /*  8:MAXPower (2mA unit) */

    /* Interface Descriptor */
    9,                              /*  0:bLength */
    USB_DT_INTERFACE,               /*  1:bDescriptor */
    0,                              /*  2:bInterfaceNumber */
    0,                              /*  3:bAlternateSetting */
    1,                              /*  4:bNumEndpoints */
    USB_IFCLS_CDCC,                 /*  5:bInterfaceClass */
    USB_PCDC_CLASS_SUBCLASS_CODE_ABS_CTR_MDL,   /*  6:bInterfaceSubClass */
    1,                              /*  7:bInterfaceProtocol */
    0,                              /*  8:iInterface */

        /* Communications Class Functional Descriptorss */
        5, /*  0:bLength */
        USB_PCDC_CS_INTERFACE,      /*  1:bDescriptorType */
        USB_PCDC_DT_SUBTYPE_HEADER_FUNC,    /*  2:bDescriptorSubtype */
        USB_PCDC_BCD_CDC % USB_PCDC_BCD_CDC_MASK,     /*  3:bcdCDC_lo */
        USB_PCDC_BCD_CDC / USB_PCDC_BCD_CDC_MASK,     /*  4:bcdCDC_hi */

        /* Communications Class Functional Descriptorss */
        4,                          /*  0:bLength */
        USB_PCDC_CS_INTERFACE,      /*  1:bDescriptorType */
        USB_PCDC_DT_SUBTYPE_ABSTRACT_CTR_MANAGE_FUNC,   /*  2:bDescriptorSubtype */
        2,                          /*  3:bmCapabilities */

        /* Communications Class Functional Descriptorss */
        5,                          /*  0:bLength */
        USB_PCDC_CS_INTERFACE,      /*  1:bDescriptorType */
        USB_PCDC_DT_SUBTYPE_UNION_FUNC, /*  2:bDescriptorSubtype */
        0,                          /*  3:bMasterInterface */
        1,                          /*  4:bSlaveInterface0 */

        /* Communications Class Functional Descriptorss */
        5,                          /*  0:bLength */
        USB_PCDC_CS_INTERFACE,      /*  1:bDescriptorType */
        USB_PCDC_DT_SUBTYPE_CALL_MANAGE_FUNC,   /*  2:bDescriptorSubtype */
        /* D1:1-Device can send/receive call management
         information over a Data Class interface. */
        /* D0:1-Device handles call management itself. */
        3,                          /*  3:bmCapabilities */
        1,                          /*  4:bDataInterface */

        /* Endpoint Descriptor 0 */
        7,                          /*  0:bLength */
        USB_DT_ENDPOINT,            /*  1:bDescriptorType */
        USB_EP_IN | USB_EP3,        /*  2:bEndpointAddress */
        USB_EP_INT,                 /*  3:bmAttribute */
        16,                         /*  4:wMAXPacketSize_lo */
        0,                          /*  5:wMAXPacketSize_hi */
        0x10,                       /*  6:bInterval */

    /* Interface Descriptor */
    9,                              /*  0:bLength */
    USB_DT_INTERFACE,               /*  1:bDescriptor */
    1,                              /*  2:bInterfaceNumber */
    0,                              /*  3:bAlternateSetting */
    2,                              /*  4:bNumEndpoints */
    USB_IFCLS_CDCD,                 /*  5:bInterfaceClass */
    0,                              /*  6:bInterfaceSubClass */
    0,                              /*  7:bInterfaceProtocol */
    0,                              /*  8:iInterface */

        /* Endpoint Descriptor 0 */
        7,                          /*  0:bLength */
        USB_DT_ENDPOINT,            /*  1:bDescriptorType */
        USB_EP_IN | USB_EP1,        /*  2:bEndpointAddress */
        USB_EP_BULK,                /*  3:bmAttribute */
        0,                          /*  4:wMAXPacketSize_lo */
        2,                          /*  5:wMAXPacketSize_hi */
        0,                          /*  6:bInterval */

        /* Endpoint Descriptor 1 */
        7,                          /*  0:bLength */
        USB_DT_ENDPOINT,            /*  1:bDescriptorType */
        USB_EP_OUT | USB_EP2,       /*  2:bEndpointAddress */
        USB_EP_BULK,                /*  3:bmAttribute */
        0,                          /*  4:wMAXPacketSize_lo */
        2,                          /*  5:wMAXPacketSize_hi */
        0,                          /*  6:bInterval */
};

/*************************************
 *    String Descriptor              *
 *************************************/
/* UNICODE 0x0409 English (United States) */
uint8_t g_cdc_string_descriptor0[STRING_DESCRIPTOR0_LEN + ( STRING_DESCRIPTOR0_LEN % 2)] =
{
    STRING_DESCRIPTOR0_LEN,     /*  0:bLength */
    USB_DT_STRING,              /*  1:bDescriptorType */
    0x09, 0x04                  /*  2:wLANGID[0] */
};

/* iManufacturer */
uint8_t g_cdc_string_descriptor1[STRING_DESCRIPTOR1_LEN + ( STRING_DESCRIPTOR1_LEN % 2)] =
{
    STRING_DESCRIPTOR1_LEN,     /*  0:bLength */
    USB_DT_STRING,              /*  1:bDescriptorType */
    'R', 0x00,                  /*  2:wLANGID[0] */
    'E', 0x00,
    'N', 0x00,
    'E', 0x00,
    'S', 0x00,
    'A', 0x00,
    'S', 0x00,
};

/* iProduct */
uint8_t g_cdc_string_descriptor2[STRING_DESCRIPTOR2_LEN + ( STRING_DESCRIPTOR2_LEN % 2)] =
{
    STRING_DESCRIPTOR2_LEN, /*  0:bLength */
    USB_DT_STRING,          /*  1:bDescriptorType */
    'C', 0x00,
    'D', 0x00,
    'C', 0x00,
    ' ', 0x00,
    'U', 0x00,
    'S', 0x00,
    'B', 0x00,
    ' ', 0x00,
    'D', 0x00,
    'e', 0x00,
    'm', 0x00,
    'o', 0x00,
    'n', 0x00,
    's', 0x00,
    't', 0x00,
    'r', 0x00,
    'a', 0x00,
    't', 0x00,
    'i', 0x00,
    'o', 0x00,
    'n', 0x00,
};

/* iInterface */
uint8_t g_cdc_string_descriptor3[STRING_DESCRIPTOR3_LEN + ( STRING_DESCRIPTOR3_LEN % 2)] =
{
    STRING_DESCRIPTOR3_LEN, /*  0:bLength */
    USB_DT_STRING,          /*  1:bDescriptorType */
    'C', 0x00,
    'o', 0x00,
    'm', 0x00,
    'm', 0x00,
    'u', 0x00,
    'n', 0x00,
    'i', 0x00,
    'c', 0x00,
    'a', 0x00,
    't', 0x00,
    'i', 0x00,
    'o', 0x00,
    'n', 0x00,
    's', 0x00,
    ' ', 0x00,
    'D', 0x00,
    'e', 0x00,
    'v', 0x00,
    'i', 0x00,
    'c', 0x00,
    'e', 0x00,
    's', 0x00
};

/* iConfiguration */
uint8_t g_cdc_string_descriptor4[STRING_DESCRIPTOR4_LEN + ( STRING_DESCRIPTOR4_LEN % 2)] =
{
    STRING_DESCRIPTOR4_LEN, /*  0:bLength */
    USB_DT_STRING,          /*  1:bDescriptorType */
    'F', 0x00,              /*  2:wLANGID[0] */
    'u', 0x00,
    'l', 0x00,
    'l', 0x00,
    '-', 0x00,
    'S', 0x00,
    'p', 0x00,
    'e', 0x00,
    'e', 0x00,
    'd', 0x00
};

/* iConfiguration */
uint8_t g_cdc_string_descriptor5[STRING_DESCRIPTOR5_LEN + ( STRING_DESCRIPTOR5_LEN % 2)] =
{
    STRING_DESCRIPTOR5_LEN, /*  0:bLength */
    USB_DT_STRING,          /*  1:bDescriptorType */
    'H', 0x00,              /*  2:wLANGID[0] */
    'i', 0x00,
    '-', 0x00,
    'S', 0x00,
    'p', 0x00,
    'e', 0x00,
    'e', 0x00,
    'd', 0x00
};

/* iSerialNumber */
uint8_t g_cdc_string_descriptor6[STRING_DESCRIPTOR6_LEN + ( STRING_DESCRIPTOR6_LEN % 2)] =
{
    STRING_DESCRIPTOR6_LEN, /*  0:bLength */
    USB_DT_STRING,          /*  1:bDescriptorType */
    '0', 0x00,              /*  2:wLANGID[0] */
    '0', 0x00,
    '0', 0x00,
    '0', 0x00,
    '0', 0x00,
    '0', 0x00,
    '0', 0x00,
    '0', 0x00,
    '0', 0x00,
    '0', 0x00,
    '0', 0x00,
    '0', 0x00,
    '1', 0x00,
};

uint8_t *g_apl_string_table[] =
{
    g_cdc_string_descriptor0,
    g_cdc_string_descriptor1,
    g_cdc_string_descriptor2,
    g_cdc_string_descriptor3,
    g_cdc_string_descriptor4,
    g_cdc_string_descriptor5,
    g_cdc_string_descriptor6
};

/******************************************************************************
 Renesas Abstracted Peripheral Communications Devices Class Driver API functions
 ******************************************************************************/

/******************************************************************************
 End  Of File
 ******************************************************************************/

修改 src/hal_entry.c 源文件，在里面添加 USB CDC相關代碼如下。

... ...
#define APP_ERR_TRAP(a)             if(a) {__asm("BKPT #0
");} /* trap the error location */

/* Global variables */
extern uint8_t  g_apl_device[];
extern uint8_t  g_apl_configuration[];
extern uint8_t  g_apl_hs_configuration[];
extern uint8_t  g_apl_qualifier_descriptor[];
extern uint8_t *g_apl_string_table[];

#define LINE_CODING_LENGTH          (0x07U)
#define READ_BUF_SIZE               (8U)
#define NUM_STRING_DESCRIPTOR       (7U)
const usb_descriptor_t usb_descriptor =
{
 g_apl_device,                   /* Pointer to the device descriptor */
 g_apl_configuration,            /* Pointer to the configuration descriptor for Full-speed */
 g_apl_hs_configuration,         /* Pointer to the configuration descriptor for Hi-speed */
 g_apl_qualifier_descriptor,     /* Pointer to the qualifier descriptor */
 g_apl_string_table,             /* Pointer to the string descriptor table */
 NUM_STRING_DESCRIPTOR
};

usb_status_t            usb_event;
static bool  b_usb_attach = false;

static fsp_err_t usb_pcdc_echo_back(char *p_data);

... ...

void hal_entry(void)
{
    /* TODO: add your own code here */
    fsp_err_t err                           = FSP_SUCCESS;
    usb_event_info_t    event_info          = {0};
    uint8_t g_buf[READ_BUF_SIZE]            = {0};
    static usb_pcdc_linecoding_t g_line_coding;

    R_BSP_PinAccessEnable(); /* Enable access to the PFS registers. */

    console_initialize();
    printf("Hello EK-RA6M4 Board
");

    /* Open USB instance */
    err = R_USB_Open (&g_basic0_ctrl, &g_basic0_cfg);
    /* Handle error */
    if (FSP_SUCCESS != err)
    {
        /* Turn ON RED LED to indicate fatal error */
        turn_led(BSP_LEDRED, BSP_LEDON);
        APP_ERR_TRAP(err);
    }

    while (1)
    {
        /* Obtain USB related events */
        err = R_USB_EventGet (&event_info, &usb_event);

        /* Handle error */
        if (FSP_SUCCESS != err)
        {
            /* Turn ON RED LED to indicate fatal error */
            turn_led(BSP_LEDRED, BSP_LEDON);
            APP_ERR_TRAP(err);
        }

        /* USB event received by R_USB_EventGet */
        switch (usb_event)
        {
            case USB_STATUS_CONFIGURED:
            {
                err = R_USB_Read (&g_basic0_ctrl, g_buf, READ_BUF_SIZE, USB_CLASS_PCDC);
                /* Handle error */
                if (FSP_SUCCESS != err)
                {
                    /* Turn ON RED LED to indicate fatal error */
                    turn_led(BSP_LEDRED, BSP_LEDON);
                    APP_ERR_TRAP(err);
                }

                break;
            }

            case USB_STATUS_READ_COMPLETE:
            {
                if(b_usb_attach)
                {
                    err = R_USB_Read (&g_basic0_ctrl, g_buf, READ_BUF_SIZE, USB_CLASS_PCDC);
                }
                /* Handle error */
                if (FSP_SUCCESS != err)
                {
                    /* Turn ON RED LED to indicate fatal error */
                    turn_led(BSP_LEDRED, BSP_LEDON);
                    APP_ERR_TRAP(err);
                }

                usb_pcdc_echo_back((char *)g_buf);
                printf("USB read data: 0x%02x->%c
", g_buf[0], g_buf[0]);
                break;
            }

            case USB_STATUS_REQUEST : /* Receive Class Request */
            {
                /* Check for the specific CDC class request IDs */
                if (USB_PCDC_SET_LINE_CODING == (event_info.setup.request_type & USB_BREQUEST))
                {
                    err =  R_USB_PeriControlDataGet (&g_basic0_ctrl, (uint8_t *) &g_line_coding, LINE_CODING_LENGTH );
                    /* Handle error */
                    if (FSP_SUCCESS != err)
                    {
                        /* Turn ON RED LED to indicate fatal error */
                        turn_led(BSP_LEDRED, BSP_LEDON);
                        APP_ERR_TRAP(err);
                    }
                }
                else if (USB_PCDC_GET_LINE_CODING == (event_info.setup.request_type & USB_BREQUEST))
                {
                    err =  R_USB_PeriControlDataSet (&g_basic0_ctrl, (uint8_t *) &g_line_coding, LINE_CODING_LENGTH );
                    /* Handle error */
                    if (FSP_SUCCESS != err)
                    {
                        /* Turn ON RED LED to indicate fatal error */
                        turn_led(BSP_LEDRED, BSP_LEDON);
                        APP_ERR_TRAP(err);
                    }
                }
                else if (USB_PCDC_SET_CONTROL_LINE_STATE == (event_info.setup.request_type & USB_BREQUEST))
                {
                    err = R_USB_PeriControlStatusSet (&g_basic0_ctrl, USB_SETUP_STATUS_ACK);
                    /* Handle error */
                    if (FSP_SUCCESS != err)
                        //if (FSP_SUCCESS != g_err)
                    {
                        /* Turn ON RED LED to indicate fatal error */
                        turn_led(BSP_LEDRED, BSP_LEDON);
                        APP_ERR_TRAP(err);
                    }
                }
                else
                {
                    /* none */
                }

                break;
            }

            case USB_STATUS_DETACH:
            case USB_STATUS_SUSPEND:
            {
                b_usb_attach = false;
                memset (g_buf, 0, sizeof(g_buf));
                break;
            }
            case USB_STATUS_RESUME:
            {
                b_usb_attach = true;
                break;
            }
            default:
            {
                break;
            }
        }
    }

#if BSP_TZ_SECURE_BUILD
    /* Enter non-secure code */
    R_BSP_NonSecureEnter();
#endif
}

/*****************************************************************************************************************
 *  @brief      Check for write completion
 *  @param[in]  None
 *  @retval     FSP_SUCCESS     Upon success
 *  @retval     any other error code apart from FSP_SUCCESS
 ****************************************************************************************************************/
static fsp_err_t check_for_write_complete(void)
{
    usb_status_t usb_write_event = USB_STATUS_NONE;
    int32_t timeout_count = UINT16_MAX;
    fsp_err_t err = FSP_SUCCESS;
    usb_event_info_t    event_info = {0};

    do
    {
        err = R_USB_EventGet (&event_info, &usb_write_event);
        if (FSP_SUCCESS != err)
        {
            return err;
        }

        --timeout_count;

        if (0 > timeout_count)
        {
            timeout_count = 0;
            err = (fsp_err_t)USB_STATUS_NONE;
            break;
        }
    }while(USB_STATUS_WRITE_COMPLETE != usb_write_event);

    return err;
}

/*****************************************************************************************************************
 *  @brief      Prints the message to console
 *  @param[in]  p_msg contains address of buffer to be printed
 *  @retval     FSP_SUCCESS     Upon success
 *  @retval     any other error code apart from FSP_SUCCESS, Write is unsuccessful
 ****************************************************************************************************************/
static fsp_err_t usb_pcdc_echo_back(char *p_data)
{
    fsp_err_t err = FSP_SUCCESS;
    uint32_t len = ((uint32_t)strlen(p_data));

    err = R_USB_Write (&g_basic0_ctrl, (uint8_t*)p_data, len, USB_CLASS_PCDC);
    /* Handle error */
    if (FSP_SUCCESS != err)
    {
        return err;
    }

    err = check_for_write_complete();
    if (FSP_SUCCESS != err)
    {
        /* Did not get the event hence returning error */
        return FSP_ERR_USB_FAILED;
    }
    return err;
}

9.4 編譯運行

代碼修改完成后，在開發板上編譯運行。將J11上的Micro USB接到電腦上，在Window的設備管理器上將會看到新的串口設備(如下面的COM9)。

接下來在USB的虛擬串口COM9上發送數據，將會收到回顯數據，另外Console串口上也會打印收到的數據。