150
Atmel ATmega16/32/64/M1/C1 [DATASHEET]
7647K–AVR–12/13
16.5.2.2 Tx Data and Remote Frame
1.
Several fields must be initialized before sending:
●
Identifier tag (IDT)
●
Identifier extension (IDE)
●
Remote transmission request (RTRTAG)
●
Data length code (DLC)
●
Reserved bit(s) tag (RBnTAG)
●
Data bytes of message (MSG)
2.
The MOb is ready to send a data or a remote frame when the MOb configuration is set (CONMOB).
3.
Then, the CAN channel scans all the MObs in Tx configuration, finds the MOb having the highest priority and tries to
send it.
4.
When the transmission is completed the TXOK flag is set (interrupt).
5.
All the parameters and data are available in the MOb until a new initialization.
16.5.2.3 Rx Data and Remote Frame
1.
Several fields must be initialized before receiving:
●
Identifier tag (IDT)
●
Identifier mask (IDMSK)
●
Identifier extension (IDE)
●
Identifier extension mask (IDEMSK)
●
Remote transmission request (RTRTAG)
●
Remote transmission request mask (RTRMSK)
●
Data length code (DLC)
●
Reserved bit(s) tag (RBnTAG)
2.
The MOb is ready to receive a data or a remote frame when the MOb configuration is set (CONMOB).
3.
When a frame identifier is received on CAN network, the CAN channel scans all the MObs in receive mode, tries to
find the MOb having the highest priority which is matching.
4.
On a hit, the IDT, the IDE and the DLC of the matched MOb are updated from the incoming (frame) values.
5.
Once the reception is completed, the data bytes of the received message are stored (not for remote frame) in the
data buffer of the matched MOb and the RXOK flag is set (interrupt).
6.
All the parameters and data are available in the MOb until a new initialization.
16.5.2.4 Automatic Reply
A reply (data frame) to a remote frame can be automatically sent after reception of the expected remote frame.
1.
Several fields must be initialized before receiving the remote frame:
●
2.
When a remote frame matches, automatically the RTRTAG and the reply valid bit (RPLV) are reset. No flag (or inter-
rupt) is set at this time. Since the CAN data buffer has not been used by the incoming remote frame, the MOb is then
ready to be in transmit mode without any more setting. The IDT, the IDE, the other tags and the DLC of the received
remote frame are used for the reply.
3.
When the transmission of the reply is completed the TXOK flag is set (interrupt).
4.
All the parameters and data are available in the MOb until a new initialization.