File syn_isotp.h¶

FileList > proto > syn_isotp.h

ISO 15765-2 (DoCAN / ISO-TP) Multi-Frame CAN Transport Protocol. More...

#include "../common/syn_defs.h"
#include "../drivers/syn_can.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>

Classes¶

Type	Name
struct	SYN_ISOTP_Link ISO 15765-2 Link Handle.

Public Types¶

Type	Name
enum	SYN_ISOTP_RxState ISO-TP Rx States.
enum	SYN_ISOTP_TxState ISO-TP Tx States.
typedef intptr_t	ssize_t

Public Functions¶

Type	Name
bool	syn_isotp_get_tx_frame (SYN_ISOTP_Link * link, SYN_CAN_Frame * frame) Retrieve next pending outgoing CAN frame from ISO-TP engine.
void	syn_isotp_init (SYN_ISOTP_Link * link, uint32_t rx_id, uint32_t tx_id, uint8_t * rx_buf, size_t rx_buf_size, uint8_t * tx_buf, size_t tx_buf_size) Initialize ISO-TP Link in Classic CAN mode (8-byte frames).
void	syn_isotp_process_rx_frame (SYN_ISOTP_Link * link, const SYN_CAN_Frame * frame) Process an incoming CAN frame into the ISO-TP engine.
ssize_t	syn_isotp_receive (SYN_ISOTP_Link * link, uint8_t * out_buf, size_t max_len) Read completed assembled message from ISO-TP receiver.
SYN_Status	syn_isotp_send (SYN_ISOTP_Link * link, const uint8_t * payload, size_t payload_len) Initiate transmission of a multi-byte payload.
void	syn_isotp_set_timeouts (SYN_ISOTP_Link * link, uint32_t n_bs_ms, uint32_t n_cr_ms) Configure custom ISO 15765-2 network layer timeouts.
void	syn_isotp_step (SYN_ISOTP_Link * link, uint32_t dt_ms) Step ISO-TP timers (milliseconds).
void	syn_isotp_step_us (SYN_ISOTP_Link * link, uint32_t dt_us) Step ISO-TP timers (microseconds for fine STmin pacing).

Macros¶

Type	Name
define	SYN_ISOTP_DEFAULT_N_BS_MS `1000U` ISO 15765-2 Network Layer Default Timeouts (ISO 15765-2:2016)
define	SYN_ISOTP_DEFAULT_N_CR_MS `1000U`
define	SYN_ISOTP_FC_CTS `0x00U` Flow Control Status (FC)
define	SYN_ISOTP_FC_OVERFLOW `0x02U`
define	SYN_ISOTP_FC_WAIT `0x01U`
define	SYN_ISOTP_MAX_PAYLOAD `4095U` ISO-TP Protocol Constants.
define	SYN_ISOTP_PCI_CF `0x20U`
define	SYN_ISOTP_PCI_FC `0x30U`
define	SYN_ISOTP_PCI_FF `0x10U`
define	SYN_ISOTP_PCI_SF `0x00U`
define	_SSIZE_T
define	_SSIZE_T_
define	_SSIZE_T_DECLARED
define	_SSIZE_T_DEFINED
define	_SSIZE_T_DEFINED_
define	__ssize_t_defined

Detailed Description¶

Implements non-blocking, zero-malloc ISO 15765-2 segmentation & reassembly for multi-byte CAN payload transmission with Single Frame (SF), First Frame (FF), Consecutive Frame (CF), and Flow Control (FC) support.

Fully supports ISO 15765-2:2016 Full-Duplex communication mode (concurrent, non-blocking, bi-directional multi-frame transmission and reception on a single link context).

Support for CAN FD (64-byte payload frames & ISO 15765-2:2016 extended length) is opt-in via #define SYN_USE_CAN_FD 1.

Usage Example (STM32 / Hardware CAN Integration)¶

static SYN_ISOTP_Link isotp_link;
static uint8_t rx_buf[256];
static uint8_t tx_buf[256];

void app_init(void) {
    // Init link: Rx CAN ID 0x7E8 (from ECU), Tx CAN ID 0x7E0 (to ECU)
    syn_isotp_init(&isotp_link, 0x7E8, 0x7E0,
                   rx_buf, sizeof(rx_buf),
                   tx_buf, sizeof(tx_buf));
}

// 1. Called when STM32 CAN RX interrupt receives a CAN frame:
void HAL_CAN_RxFifo0MsgPendingCallback(CAN_HandleTypeDef *hcan) {
    CAN_RxHeaderTypeDef rx_hdr;
    SYN_CAN_Frame frame;
    HAL_CAN_GetRxMessage(hcan, CAN_RX_FIFO0, &rx_hdr, frame.data);
    frame.id  = rx_hdr.StdId;
    frame.dlc = rx_hdr.DLC;
    syn_isotp_process_rx_frame(&isotp_link, &frame);
}

// 2. Called in main loop / task:
void app_loop(void) {
    // Step timers (1ms dt)
    syn_isotp_step(&isotp_link, 1);

    // Drain & transmit pending CAN frames generated by ISO-TP engine
    SYN_CAN_Frame tx_frame;
    while (syn_isotp_get_tx_frame(&isotp_link, &tx_frame)) {
        CAN_TxHeaderTypeDef tx_hdr = { .StdId = tx_frame.id, .DLC = tx_frame.dlc };
        uint32_t mailbox;
        HAL_CAN_AddTxMessage(&hcan1, &tx_hdr, tx_frame.data, &mailbox);
    }

    // Read fully assembled received messages
    uint8_t payload[128];
    ssize_t len = syn_isotp_receive(&isotp_link, payload, sizeof(payload));
    if (len > 0) {
        // Process UDS diagnostic response...
    }
}

Public Types Documentation¶

enum SYN_ISOTP_RxState¶

ISO-TP Rx States.

enum SYN_ISOTP_RxState {
    SYN_ISOTP_RX_IDLE = 0,
    SYN_ISOTP_RX_WAIT_CF,
    SYN_ISOTP_RX_COMPLETE
};

enum SYN_ISOTP_TxState¶

ISO-TP Tx States.

enum SYN_ISOTP_TxState {
    SYN_ISOTP_TX_IDLE = 0,
    SYN_ISOTP_TX_SEND_SF,
    SYN_ISOTP_TX_SEND_FF,
    SYN_ISOTP_TX_WAIT_FC,
    SYN_ISOTP_TX_SEND_CF
};

typedef ssize_t¶

typedef intptr_t ssize_t;

Public Functions Documentation¶

function syn_isotp_get_tx_frame¶

Retrieve next pending outgoing CAN frame from ISO-TP engine.

bool syn_isotp_get_tx_frame (
    SYN_ISOTP_Link * link,
    SYN_CAN_Frame * frame
)

Parameters:

link Link handle.
frame Output CAN frame buffer.

Returns:

true if a frame was generated, false otherwise.

function syn_isotp_init¶

Initialize ISO-TP Link in Classic CAN mode (8-byte frames).

void syn_isotp_init (
    SYN_ISOTP_Link * link,
    uint32_t rx_id,
    uint32_t tx_id,
    uint8_t * rx_buf,
    size_t rx_buf_size,
    uint8_t * tx_buf,
    size_t tx_buf_size
)

Parameters:

link Link handle.
rx_id Incoming CAN identifier.
tx_id Outgoing CAN identifier.
rx_buf Receive assembly buffer.
rx_buf_size Receive buffer capacity.
tx_buf Transmit buffer.
tx_buf_size Transmit buffer capacity.

function syn_isotp_process_rx_frame¶

Process an incoming CAN frame into the ISO-TP engine.

void syn_isotp_process_rx_frame (
    SYN_ISOTP_Link * link,
    const SYN_CAN_Frame * frame
)

Parameters:

link Link handle.
frame Incoming CAN frame.

function syn_isotp_receive¶

Read completed assembled message from ISO-TP receiver.

ssize_t syn_isotp_receive (
    SYN_ISOTP_Link * link,
    uint8_t * out_buf,
    size_t max_len
)

Parameters:

link Link handle.
out_buf Output buffer.
max_len Capacity of out_buf.

Returns:

Number of bytes copied, or -1 if no message ready.

function syn_isotp_send¶

Initiate transmission of a multi-byte payload.

SYN_Status syn_isotp_send (
    SYN_ISOTP_Link * link,
    const uint8_t * payload,
    size_t payload_len
)

Parameters:

link Link handle.
payload Payload buffer.
payload_len Length of payload (1 to max buffer capacity).

Returns:

SYN_OK on success, error code on busy/invalid params.

function syn_isotp_set_timeouts¶

Configure custom ISO 15765-2 network layer timeouts.

void syn_isotp_set_timeouts (
    SYN_ISOTP_Link * link,
    uint32_t n_bs_ms,
    uint32_t n_cr_ms
)

Parameters:

link Link handle.
n_bs_ms N_Bs max timeout in milliseconds (0 = use default 1000ms).
n_cr_ms N_Cr max timeout in milliseconds (0 = use default 1000ms).

function syn_isotp_step¶

Step ISO-TP timers (milliseconds).

void syn_isotp_step (
    SYN_ISOTP_Link * link,
    uint32_t dt_ms
)

Parameters:

link Link handle.
dt_ms Elapsed time in milliseconds.

function syn_isotp_step_us¶

Step ISO-TP timers (microseconds for fine STmin pacing).

void syn_isotp_step_us (
    SYN_ISOTP_Link * link,
    uint32_t dt_us
)

Parameters:

link Link handle.
dt_us Elapsed time in microseconds.

Macro Definition Documentation¶

define SYN_ISOTP_DEFAULT_N_BS_MS¶

ISO 15765-2 Network Layer Default Timeouts (ISO 15765-2:2016)

#define SYN_ISOTP_DEFAULT_N_BS_MS `1000U`

N_Bs max time for FC reception (1000 ms)

define SYN_ISOTP_DEFAULT_N_CR_MS¶

#define SYN_ISOTP_DEFAULT_N_CR_MS `1000U`

N_Cr max time for CF reception (1000 ms)

define SYN_ISOTP_FC_CTS¶

Flow Control Status (FC)

#define SYN_ISOTP_FC_CTS `0x00U`

Continue To Send

define SYN_ISOTP_FC_OVERFLOW¶

#define SYN_ISOTP_FC_OVERFLOW `0x02U`

Buffer Overflow

define SYN_ISOTP_FC_WAIT¶

#define SYN_ISOTP_FC_WAIT `0x01U`

Wait

define SYN_ISOTP_MAX_PAYLOAD¶

ISO-TP Protocol Constants.

#define SYN_ISOTP_MAX_PAYLOAD `4095U`

Standard 12-bit max payload (Classic CAN)

define SYN_ISOTP_PCI_CF¶

#define SYN_ISOTP_PCI_CF `0x20U`

Consecutive Frame

define SYN_ISOTP_PCI_FC¶

#define SYN_ISOTP_PCI_FC `0x30U`

Flow Control Frame

define SYN_ISOTP_PCI_FF¶

#define SYN_ISOTP_PCI_FF `0x10U`

First Frame

define SYN_ISOTP_PCI_SF¶

#define SYN_ISOTP_PCI_SF `0x00U`

Single Frame

define _SSIZE_T¶

#define _SSIZE_T

define _SSIZE_T_¶

#define _SSIZE_T_

define _SSIZE_T_DECLARED¶

#define _SSIZE_T_DECLARED

define _SSIZE_T_DEFINED¶

#define _SSIZE_T_DEFINED

define _SSIZE_T_DEFINED_¶

#define _SSIZE_T_DEFINED_

define __ssize_t_defined¶

#define __ssize_t_defined

The documentation for this class was generated from the following file src/syntropic/proto/syn_isotp.h