ST ST10F276E - Page 432

CAN modules UM0404
432/564 DocID13284 Rev 2
Direction Read:
IFx message buffer registers
The bits of the Message Buffer registers mirror the Message Objects in the Message RAM.
The function of the Message Objects bits is described in Message object in the message
memory on page 438.
Control
Access Control Bits
’0’: Control Bits unchanged.
’1’: Transfer Control Bits to Message Object.
Arb
Access Arbitration Bits
’0’: Arbitration bits unchanged.
’1’: Transfer Identifier + Dir + Xtd + MsgVal to Message Object.
Mask
Access Mask Bits
’0’: Mask bits unchanged.
’1’: Transfer Identifier Mask + MDir + MXtd to Message Object.
Bit Function
Data B
Access Data Bytes 4-7
’0’: Data Bytes 4-7 unchanged.
’1’: Transfer Data Bytes 4-7 to IFx Message Buffer Register.
Data A
Access Data Bytes 0-3
’0’: Data Bytes 0-3 unchanged.
’1’: Transfer Data Bytes 0-3 to IFx Message Buffer Register.
TxRqst/NewDat
Access Transmission Request Bit
’0’: NewDat bit remains unchanged.
’1’: Clear NewDat bit in the Message Object.
A read access to a Message Object can be combined with the reset of the control
bits IntPnd and NewDat. The values of these bits transferred to the IFx Message
Control Register always reflect the status before resetting these bits.
ClrIntPnd
Clear Interrupt Pending Bit
’0’: IntPnd bit remains unchanged.
’1’: clear IntPnd bit in the Message Object.
Control
Access Control Bits
’0’: Control Bits unchanged.
’1’: Transfer Control Bits to IFx Message Buffer Register.
Arb
Access Arbitration Bits
’0’: Arbitration bits unchanged.
’1’: Transfer Identifier + Dir + Xtd + MsgVal to IFx Message Buffer Register.
Mask
Access Mask Bits
’0’: Mask bits unchanged.
’1’: Transfer Identifier Mask + MDir + MXtd to IFx Message Buffer Register.
Bit Function