AN1105 datasheet(27/100 Pages) STMICROELECTRONICS

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ST7 pCAN PERIPHERAL DRIVER

void CAN_Bus_Off_Notification(void)

These functions are called after a status change.

Option: #define STATUS_CHANGE_NOTIFICATION

void CAN_General_Reception_Error_Notification(void)

This function notifies the application of any hardware reception errors.

Option: #define DEBUG and #define GENERAL_RECEPTION_ERROR

void CAN_Reception_Status(CAN_Receive_Error status)

This function is called after a reception attempt and returns the status of the software

processing (See “Enum -type variables” on page 20).

Option: #define DEBUG

void CAN_Overrun_Notification(void)

This function notifies the application of any overruns.

Option: #define DEBUG

void CAN_Transmission_Error_Notification(CAN_Transmit_Error status)

This function notifies the application of any hardware transmission errors.

Option: #define DEBUG

2.2 HOW TO USE THE CAN DRIVER: A DEMO APPLICATION

In this section, we will describe step-by-step the configuration and programming of a simple

test application using the ST7 CAN driver.

2.2.1 Application

First of all, we must define how the application will look, i.e. which messages our cell will be

able to send, which ones it will accept to receive, and how it will behave when specific mes-

sages are received.

Let’s imagine the following:

– The cell has to run immediately after power-on, and does not have to send a dominant pulse.

– Every 15 ms the cell must send the contents of the ST7 A/D Converter data register. The

identifier (ID) of this message could be, for example, 0x402.

– Upon reception of a remote frame (see Section 1.2 "CAN Frame") it must reply with the trans-

mission of a given message. The ID of the remote frame could be, for example, 0x500 (con-

sequently, the ID of the answer will also be 0x500).

– Upon reception of a given data item, the CAN cell must shut down. This ID of the message

could be 0x600, and the data item 0xFF, in its first data byte.

– The cell is supposed to receive 3 other data messages coming from other nodes. Let’s im-

agine they are identified by 0x127, 0x311, 0x3A5.

AN1105 датащи(PDF) 27 Page - STMicroelectronics