Texas Instruments Tiva TM4C123GH6PM, User Manual

Page: 63 / 352

Controller Area Network (CAN)
Prototype:
void
ROM_CANMessageGet(uint32_t ui32Base,
uint32_t ui32ObjID,
tCANMsgObject *pMsgObject,
bool bClrPendingInt)
ROM Location:
ROM_APITABLE
is an array of pointers located at
0x0100.0010
.
ROM_CANTABLE
is an array of pointers located at
ROM_APITABLE[18]
.
ROM_CANMessageGet
is a function pointer located at
ROM_CANTABLE[7]
.
Parameters:
ui32Base is the base address of the CAN controller.
ui32ObjID is the object number to read (1-32).
pMsgObject points to a structure containing message object fields.
bClrPendingInt indicates whether an associated interrupt should be cleared.
Description:
This function is used to read the contents of one of the 32 message objects in the CAN con-
troller, and return it to the caller. The data returned is stored in the fields of the caller-supplied
structure pointed to by
pMsgObject . The data consists of all of the parts of a CAN message,
plus some control and status information.
Normally this is used to read a message object that has received and stored a CAN message
with a certain identifier. However, this could also be used to read the contents of a message
object in order to load the fields of the structure in case only part of the structure needs to be
changed from a previous setting.
When using CANMessageGet, all of the same fields of the structure are populated in the same
way as when the
ROM_CANMessageSet() function is used, with the following exceptions:
pMsgObject- > ui32Flags:
MSG_OBJ_NEW_DATA indicates if this is new data since the last time it was read
MSG_OBJ_DATA_LOST indicates that at least one message was received on this mes-
sage object, and not read by the host before being overwritten.
Returns:
None.
6.2.1.14 ROM_CANMessageSet
Configures a message object in the CAN controller.
Prototype:
void
ROM_CANMessageSet(uint32_t ui32Base,
uint32_t ui32ObjID,
tCANMsgObject *pMsgObject,
tMsgObjType eMsgType)
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