SH7059 Datasheet, PDF (575/1042 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

17. Controller Area Network-II (HCAN-II)
HCAN1 which already receive the message on CAN bus transmits ACK in ACK field according to the CAN protocol
and HCAN0 receives the ACK.
For a countermeasure, please set the channel that will not transmit the message to reset state (MCR0=1).
2. Internal arbitration which determines transmittion order is independently carried out by HCAN0 and HCAN1,
respectively. HCAN-II has 31-transmission buffers per channel.
However, internal arbitration can not be carry out in the range of the 62-transmission buffers.
3. Please do not the same transmission message ID to HCAN0 and HCAN1.
The same ID message will be transmitted from two channels after arbitration on CAN bus.
17.7.11 CAN Bus Interface
A bus transceiver is required to connect this LSI to a CAN bus. The PCA82C250 from NXP Semiconductors is
recommended. If any other product is used, confirm that it is equivalent to the PCA82C250. Figure 17.16 shows an
example of a connection.
This LSI
HRxD1
HTxD1
Vcc
PCA82C250
RS Vcc
RxD CANH
TxD CANL
Vref GND
NC
124Ω
CAN bus
Note: NC: No Connection
124Ω
Figure 17.16 Using the PCA82C250 in a High-Speed Interface
17.8 Usage Notes
17.8.1 TXPR Setting during Reception
When the HCAN-II is used with the baud rate set to 1 Mbps and the transmission setting is made during message
reception, there are following limitations on the number of transmit mailboxes (MB) and the number of accesses to
mailboxes. Note that there is no limitation when 500 kbps of baud rate is used.
Important: Limitations on setting TXPR during reception
There are limitations on the number of mailboxes set by TXPR and the number of accesses to mailboxes.
Rev.3.00 Mar. 12, 2008 Page 485 of 948
REJ09B0177-0300