Davinci工程CAN模块讲解

CAN模块是用来配置CAN Driver的，里面有CanConfigSet是用来配置驱动内容的，CanGeneral配置参数。涉及四个文件Can_Lcfg.c/Can_Lcfg.h/Can_Cfg.c/Can_Cfg.h

CanConfigSet

CanControllers

CAN控制器，我们这里的CAN控制器只有一个，名字是默认的。

里面能够选择的就是用哪个CAN控制器，选完之后下面的基地址会改变，这个控制器是指我们MCU里面的CAN外设。

CAN控制器对应的内容是DemoFbl\Appl\GenData\Can_Lcfg.c里面，主要改变的就是基地址。

CONST(Can_ControllerConfigType, CAN_CONST) Can_ControllerConfig[1] = {  /* PRQA S 1514, 1533 */  /* MD_CSL_ObjectOnlyAccessedOnce */
    /* Index    BaseAddress  CanControllerDefaultBaudrate  TxPollingMask1  CanControllerDefaultBaudrateIdx  InterruptMask1  MailboxRxBasicEndIdx                                                                                                                                           MailboxRxBasicLength                                                                                                                                           MailboxRxBasicStartIdx                                                                                                                                           MailboxTxBasicEndIdx                                                                                                                                           MailboxTxBasicLength                                                                                                                                           MailboxTxBasicStartIdx                                                                                                                                           MailboxUnusedEndIdx                                                                                                                                          MailboxUnusedLength                                                                                                                                          MailboxUnusedStartIdx                                                                                                                                          NumberOfFilters  NumberOfFullConfigurableFilters  NumberOfMaxMailboxes  RFFN   RxBasicHwStart  RxBasicHwStop  RxFullHwStart  RxFullHwStop  TxBasicHwStart  TxBasicHwStop  TxFullHwStart  TxFullHwStop  UnusedHwStart  UnusedHwStop        Comment                         Referable Keys */
  { /*     0 */ 0x40024000u,                         500u,        0x0100u,                              0u,          0x00u,                   2u  /* RX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                   1u  /* RX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                     1u  /* RX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                   1u  /* TX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                   1u  /* TX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                     0u  /* TX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                  4u  /* UNUSED_CAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                  2u  /* UNUSED_CAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                    2u  /* UNUSED_CAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,           0x08u,                           0x08u,                0x20u, 0x00u,             0u,            1u,            8u,           8u,             8u,            9u,            9u,           9u,            1u,          32u }   /* [CT_HSCAN_bce71fc0] */  /* [/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0] */
};

发送和接收处理可以选择为轮询或者中断

/* Interrupt / Polling */
#define CAN_TX_PROCESSING                    CAN_POLLING   /* CAN318_Conf */
#define CAN_RX_PROCESSING                    CAN_POLLING   /* CAN317_Conf */
#define CAN_BUSOFF_PROCESSING                CAN_POLLING   /* CAN314_Conf */
#define CAN_WAKEUP_PROCESSING                CAN_POLLING   /* CAN319_Conf */

CanControllerBaudrateConfigs

里面只有一个CanControllerBaudrateConfig，包含CAN控制器的位时序相关配置参数，这些参数熟悉CAN通讯的基本一眼就能看出来，就是个波特率时钟、波特率分频、波特率和采样点、采样模式。TASD Value是发送仲裁延迟。

对应的内容是DemoFbl\Appl\GenData\Can_Lcfg.c里面的，这里的值就是上面配置的数值，能够一一对应的，查一下芯片规格书就行，这里就不再赘述了。

定义基地址、波特率、

#define CAN_START_SEC_CONST_UNSPECIFIED
/*lint -save -esym(961, 19.1) */
#include "MemMap.h"  /* PRQA S 5087 */  /* MD_MSR_MemMap */
/*lint -restore */
CONST(Can_ControllerConfigType, CAN_CONST) Can_ControllerConfig[1] = {  /* PRQA S 1514, 1533 */  /* MD_CSL_ObjectOnlyAccessedOnce */
    /* Index    BaseAddress  CanControllerDefaultBaudrate  TxPollingMask1  CanControllerDefaultBaudrateIdx  InterruptMask1  MailboxRxBasicEndIdx                                                                                                                                           MailboxRxBasicLength                                                                                                                                           MailboxRxBasicStartIdx                                                                                                                                           MailboxTxBasicEndIdx                                                                                                                                           MailboxTxBasicLength                                                                                                                                           MailboxTxBasicStartIdx                                                                                                                                           MailboxUnusedEndIdx                                                                                                                                          MailboxUnusedLength                                                                                                                                          MailboxUnusedStartIdx                                                                                                                                          NumberOfFilters  NumberOfFullConfigurableFilters  NumberOfMaxMailboxes  RFFN   RxBasicHwStart  RxBasicHwStop  RxFullHwStart  RxFullHwStop  TxBasicHwStart  TxBasicHwStop  TxFullHwStart  TxFullHwStop  UnusedHwStart  UnusedHwStop        Comment                         Referable Keys */
  { /*     0 */ 0x40025000u,                         500u,        0x0100u,                              0u,          0x00u,                   2u  /* RX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                   1u  /* RX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                     1u  /* RX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                   1u  /* TX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                   1u  /* TX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                     0u  /* TX_BASICCAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                  4u  /* UNUSED_CAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                  2u  /* UNUSED_CAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,                    2u  /* UNUSED_CAN_TYPE/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0 (DefRef: /MICROSAR/Can_ImxFlexcan3/Can/CanConfigSet/CanController) */,           0x08u,                           0x08u,                0x10u, 0x00u,             0u,            1u,            8u,           8u,             8u,            9u,            9u,           9u,            1u,          16u }   /* [CT_HSCAN_bce71fc0] */  /* [/ActiveEcuC/Can/CanConfigSet/CT_HSCAN_bce71fc0] */
};
#define CAN_STOP_SEC_CONST_UNSPECIFIED
/*lint -save -esym(961, 19.1) */
#include "MemMap.h"  /* PRQA S 5087 */  /* MD_MSR_MemMap */
/*lint -restore */

定义采样点

/**********************************************************************************************************************
  Can_InitObject
**********************************************************************************************************************/
/** 
  \var    Can_InitObject
  \brief  This table contains information about the init object: e.g. bustiming register contents.
  \details
  Element     Description
  CBT     
  Control1
*/ 
#define CAN_START_SEC_CONST_UNSPECIFIED
/*lint -save -esym(961, 19.1) */
#include "MemMap.h"  /* PRQA S 5087 */  /* MD_MSR_MemMap */
/*lint -restore */
CONST(Can_InitObjectType, CAN_CONST) Can_InitObject[1] = {  /* PRQA S 1514, 1533 */  /* MD_CSL_ObjectOnlyAccessedOnce */
    /* Index    CBT          Control1           Comment */
  { /*     0 */ 0x812010C2u, 0x09322004u }   /* ["CT_HSCAN_bce71fc0 - CanControllerBaudrateConfig", init object index: 0] */
};
#define CAN_STOP_SEC_CONST_UNSPECIFIED
/*lint -save -esym(961, 19.1) */
#include "MemMap.h"  /* PRQA S 5087 */  /* MD_MSR_MemMap */
/*lint -restore */

CanFilterMask

是描述CAN标识符基于硬件过滤的掩码，receiveID & Mask == Code & Mask时过滤，一般不会过滤，都是0。

如果你使用了，就会体现在DemoFbl\Appl\GenData\Can_Lcfg.c的Can_InitBasicCan里面。

CanHardwareObjects

这里面没什么好配置的，就是默认一个发送对象和一个接收对象。

拿发送对象举个例子，CanFdPaddingValue是填充数据，CanHandleType可以选择基础CAN还是full CAN。CanIdType选择CAN ID是标准、扩展还是混合的，由于我们这里是乘用车，就只需要基础的。CanIdValue也就是CAN掩码。CanObjectType只是方向是发送还是接收。