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can/Inc/mmr_can_header.h
2022-03-07 00:46:26 +01:00

86 lines
2.1 KiB
C

/**
* @file mmr_can_header.h
* @brief
* This file defines the header used for the can message,
* along with its utilities.
*
* With header is intended the ExtendedId portion
* of the can message.
*/
#ifndef INC_MMR_CAN_HEADER_H_
#define INC_MMR_CAN_HEADER_H_
#include <stdbool.h>
#include "mmr_can_util.h"
#include "mmr_can_binary_literals.h"
#include "mmr_can_message_id.h"
/**
* @brief
* These values can be appended to the extended-id
* portion of the CAN bus message (that is, the lower 5 bits
* of the standard id)
*
* They are used to check if a message is either standalone, an
* acknowledgement or split into multiple frames
*
* Constants with lower values have an higher priority.
*/
typedef enum MmrCanMessageType {
MMR_CAN_MESSAGE_TYPE_SCS = B_(0000),
MMR_CAN_MESSAGE_TYPE_ACK = B_(0001),
MMR_CAN_MESSAGE_TYPE_MULTI_FRAME = B_(0010),
MMR_CAN_MESSAGE_TYPE_MULTI_FRAME_END = B_(0011),
MMR_CAN_MESSAGE_TYPE_NORMAL = B_(0100),
} MmrCanMessageType;
typedef enum MmrCanMessagePriority {
MMR_CAN_MESSAGE_PRIORITY_LOW = B_(0010),
MMR_CAN_MESSAGE_PRIORITY_NORMAL = B_(0001),
MMR_CAN_MESSAGE_PRIORITY_HIGH = B_(0000),
} MmrCanMessagePriority;
/**
* @brief
* This struct encodes the values stored inside the
* extended id field of a CAN packet.
*/
typedef struct MmrCanHeader {
MmrCanMessagePriority priority : 3;
uint16_t messageId : 10;
uint16_t senderId : 10;
uint8_t seqNumber : 3;
MmrCanMessageType messageType : 3;
} MmrCanHeader;
/**
* @brief
* Serializes an MmrCanHeader to bits.
* That is, a 32bits integer with the first
* 3 bits set to zero and the remaining 29 containing the
* extended id
*/
uint32_t MMR_CAN_HeaderToBits(MmrCanHeader header);
/**
* @brief
* Deserializes a 32bits integer to an MmrCanHeader.
* The 3 left-most bits must be of padding.
*/
MmrCanHeader MMR_CAN_HeaderFromBits(uint32_t bits);
/**
* @brief
* Tells wether the given header represents an SCS.
*/
bool MMR_CAN_IsHeaderScs(MmrCanHeader header);
bool MMR_CAN_IsMultiFrame(MmrCanHeader header);
bool MMR_CAN_IsMultiFrameEnd(MmrCanHeader header);
#endif /* INC_MMR_CAN_HEADER_H_ */