Datasheet

Section 15 Controller Area Network for Tiny (TinyCAN)
Rev. 4.00 Mar. 15, 2006 Page 347 of 556
REJ09B0026-0400
15.9 Usage Notes
1. Since Mailboxes (MCn0, MCn4 to MCn7, and MDn0 to MDn7 (n = 0 to 3)) and LAFM are
configured of RAM, initial values are undefined after powering on. Initialize (write 0 or 1) all
Mailboxes and LAFM.
2. Set BCR1, BCR0, and the PMR97 and PMR96 bits in TMCR after initializing Mailboxes and
LAFM. Otherwise, the TinyCAN starts reception and the receive message ID may be
compared with an undefined value of RAM.
3. To change Mailbox settings from transmission to reception, confirm that TXPR is 0.
4. To change Mailbox settings from reception to transmission, confirm that both RXPR and
RFPR are 0 after transition to halt mode.
5. If MCn0, MCn4 to MCn7, and MDn0 to MDn7 (n = 0 to 3) are written to by the CPU between
the seventh EOF bit and intermission space at message reception, note that data of the receive
message may be overwritten.
6. If MCn0, MCn4 to MCn7, and MDn0 to MDn7 (n = 0 to 3) are written to by the CPU between
intermission spaces during a transmit request, note that the transmit message may be updated.
7. RXPR and RFPR are exclusively set or cleared during overwrite.
8. A wakeup operation is enabled only in LSI standby mode. Note that it is disabled in module
standby mode.
9. To enter module standby mode, make a transition to halt mode beforehand. Otherwise, when
clearing module standby mode, communication with the CAN bus resumes with the setting
before making a transition and an error occurs.
10. When an error is detected during reception, the TinyCAN clears data in the temporary buffer.