Rainbow Electronics ATmega64M1 - Manual (Page 175)

175
8209A–AVR–08/09
ATmega16M1/32M1/64M1
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.
20.6.2.3 Rx Data & 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.
20.6.2.4 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:
– Reply valid (RPLV) in a identical flow to the one described in Section 20.6.2.3 “Rx
Data & Remote Frame” on page 175 .
2. When a remote frame matches, automatically the RTRTAG and the reply valid bit
(RPLV) are reset. No flag (or interrupt) 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.
20.6.2.5 Frame Buffer Receive Mode
This mode is useful to receive multi frames. The priority between MObs offers a management for
these incoming frames. One set MObs (including non-consecutive MObs) is created when the
MObs are set in this mode. Due to the mode setting, only one set is possible. A frame buffer
completed flag (or interrupt) - BXOK - will rise only when all the MObs of the set will have
received their dedicated CAN frame.