Section 19
Controller Area Network (RCAN-TL1)
Rev. 0.50 May 18, 2006 Page 981 of 1588
REJ09B0313-0050
When RCAN-TL1 recognises the end of the Arbitration field while receiving a message, it starts
comparing the received identifier to the identifiers set in the Mailboxes, starting from Mailbox-31
down to Mailbox-0. It first checks the MBC if it is configured as a receive box, and reads LAFM,
and reads the CAN-ID of Mailbox-31 (if configured as receive) to finally compare them to the
received ID. If it does not match, the same check takes place at Mailbox-30 (if configured as
receive). Once RCAN-TL1 finds a matching identifier, it stores the number of Mailbox-[N] into
an internal buffer, stops the search, and goes back to idle state, waiting for the EndOfFrame (EOF)
to come. When the 6
th
bit of EOF is notified by the CAN Interface logic, the received message is
written or abandoned, depending on the NMC bit. No modification of configuration during
communication is allowed. Entering Halt Mode is one of ways to modify configuration. If it is
written into the corresponding Mailbox, including the CAN-ID, i.e., there is a possibility that the
CAN-ID is overwritten by a different CAN-ID of the received message due to the LAFM used.
This also implies that, if the identifier of a received message matches to ID + LAFM of 2 or more
Mailboxes, the higher numbered Mailbox will always store the relevant messages and the lower
numbered Mailbox will never receive messages. Therefore, the settings of the identifiers and
LAFMs need to be carefully selected.
With regards to the reception of data and remote frames described in the above flow diagram the
clearing of the UMSR flag after the reading of IRR is to detect situations where a message is
overwritten by a new incoming message stored in the same mailbox (if its NMC = 1) while the
interrupt service routine is running. If during the final check of UMSR a overwrite condition is
detected the message needs to be discarded and read again.
In case UMSR is set and the Mailbox is configured for overrun (NMC = 0) the message is still
valid, however it is obsolete as it is not reflecting the latest message monitored on the CAN Bus.
Please access the full Mailbox content before clearing the related RXPR/RFPR flag.
Please note that in the case a received remote frame is overwritten by a data frame, both the
remote frame receive interrupt (IRR2) and data frame received interrupt (IRR1) and also the
Receive Flags (RXPR and RFPR) are set. In an analogous way, the overwriting of a data frame by
a remote frame, leads to setting both IRR2 and IRR1.
When a message is received and stored into a Mailbox all the fields of the data not received are
stored as zero. The same applies when a standard frame is received. The extended identifier part
(EXTID[17:0]) is written as zero.
Содержание Single-Chip Microcomputer SH7203
Страница 2: ...Rev 0 50 May 18 2006 Page ii of xxx ...
Страница 30: ...Rev 0 50 May 18 2006 Page xxx of xxx ...
Страница 52: ...Section 1 Overview Rev 0 50 May 18 2006 Page 22 of 1588 REJ09B0313 0050 ...
Страница 98: ...Section 2 CPU Rev 0 50 May 18 2006 Page 68 of 1588 REJ09B0313 0050 ...
Страница 128: ...Section 4 Clock Pulse Generator CPG Rev 0 50 May 18 2006 Page 98 of 1588 REJ09B0313 0050 ...
Страница 200: ...Section 6 Interrupt Controller INTC Rev 0 50 May 18 2006 Page 170 of 1588 REJ09B0313 0050 ...
Страница 242: ...Section 8 Cache Rev 0 50 May 18 2006 Page 212 of 1588 REJ09B0313 0050 ...
Страница 400: ...Section 9 Bus State Controller BSC Rev 0 50 May 18 2006 Page 370 of 1588 REJ09B0313 0050 ...
Страница 668: ...Section 11 Multi Function Timer Pulse Unit 2 MTU2 Rev 0 50 May 18 2006 Page 638 of 1588 REJ09B0313 0050 ...
Страница 696: ...Section 13 Watchdog Timer WDT Rev 0 50 May 18 2006 Page 666 of 1588 REJ09B0313 0050 ...
Страница 726: ...Section 14 Realtime Clock RTC Rev 0 50 May 18 2006 Page 696 of 1588 REJ09B0313 0050 ...
Страница 796: ...Section 15 Serial Communication Interface with FIFO SCIF Rev 0 50 May 18 2006 Page 766 of 1588 REJ09B0313 0050 ...
Страница 876: ...Section 17 I2 C Bus Interface 3 IIC3 Rev 0 50 May 18 2006 Page 846 of 1588 REJ09B0313 0050 ...
Страница 1020: ...Section 19 Controller Area Network RCAN TL1 Rev 0 50 May 18 2006 Page 990 of 1588 REJ09B0313 0050 ...
Страница 1054: ...Section 21 D A Converter DAC Rev 0 50 May 18 2006 Page 1024 of 1588 REJ09B0313 0050 ...
Страница 1226: ...Section 23 USB 2 0 Host Function Module USB Rev 0 50 May 18 2006 Page 1196 of 1588 REJ09B0313 0050 ...
Страница 1294: ...Section 24 LCD Controller LCDC Rev 0 50 May 18 2006 Page 1264 of 1588 REJ09B0313 0050 ...
Страница 1386: ...Section 26 I O Ports Rev 0 50 May 18 2006 Page 1356 of 1588 REJ09B0313 0050 ...
Страница 1512: ...Section 30 List of Registers Rev 0 50 May 18 2006 Page 1482 of 1588 REJ09B0313 0050 ...
Страница 1598: ...Section 31 Electrical Characteristics Rev 0 50 May 18 2006 Page 1568 of 1588 REJ09B0313 0050 ...
Страница 1606: ...Appendix Rev 0 50 May 18 2006 Page 1576 of 1588 REJ09B0313 0050 ...
Страница 1618: ...Rev 0 50 May 18 2006 Page 1588 of 1588 REJ09B0313 0050 ...
Страница 1621: ......
Страница 1622: ...SH7203 Group Hardware Manual ...