AN1105 STMicroelectronics, AN1105 Datasheet - Page 19

• Manufacturer Part Number: AN1105
• Description: ST7 PCAN PERIPHERAL DRIVER
• Manufacturer: STMicroelectronics

– Error ITs are only processed if the DEBUG option was chosen in can_custom.h. Then, the
2.1.5 User Interface Description
This section describes the user interface in a “black-box” way. The parameters and the return
values of the function declared in can.h and can_custom.h are described in this section. For a
complete description of the algorithms and internal data type variables, please see
"Detailed
2.1.5.1 Data-type Variables
CAN_Buffer -type variables
typedef struct CAN_Buffer{
Software representation of CAN data. The translation into hardware buffers is performed by
the driver.
A variable of this data-type must be passed to the driver each time it is requested by the
CAN_Request_Buffer notification function (See
page
A pointer to this structure is also used as parameter of the CAN_Transmit_Request function
(See
application is notified of any other events through function calls. (Functions entered in
can_custom.c).
– msg_identifier: 2 bytes field containing the identifier of the CAN message. The identifier is
– data_size: 1 byte field containing the length of the data in the message (in bytes). The
– CAN_msg_data : array of 8 bytes containing the data to be sent. The u8u16 type means 1
– buffer_rw : this boolean variable is to be used as a flag to prevent simultaneous writing/
– buffer_free : boolean variable used to mark if the data in the buffer can be overwritten or
stored in the 12 most significant bits. The 4 least significant bits MUST be zero. The u16
type means 2 bytes unsigned variable and is defined in lib.h.
CAN_Data_Size type is an enum type (See below for its description).
byte unsigned variable and is defined in lib.h.
reading on the structure. It is checked and modified by the driver each time an operation
is being performed on the buffer. If CTRUE, the structure will not be read or written. If
CFALSE, it can be used. Always check/modify this variable in your application for this pur-
pose.
not. It has to be used as the security by the user’s application. If CFALSE, the driver will
refuse to perform any write operation on the data in the structure and return an error code.
“Functions” on page
26). Otherwise, data in the hardware buffer will be lost.
Description".
21).
u16msg_identifier;
CAN_Data_Size data_size;
u8 CAN_msg_data[CAN_MAX_DATA_SIZE];
CAN_Bool buffer_rw;
CAN_Bool buffer_free;
}CAN_Buffer;
“Functions called unconditionally” on
ST7 pCAN PERIPHERAL DRIVER
Section 3
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