
Rev.2.10 Apr 14, 2006 page 241 of 378
REJ09B0124-0210
M16C/6N Group (M16C/6NK, M16C/6NM) 19. CAN Module
19.11 Basic CAN Mode
When the BasicCAN bit in the CiCTLR register (i = 0, 1) is set to 1 (Basic CAN mode enabled), slots 14 and
15 correspond to Basic CAN mode. In normal operation mode, each slot can handle only one type message
at a time, either a data frame or a remote frame by setting CiMCTLj regisrer (j = 0 to 15). However, in Basic
CAN mode, slots 14 and 15 can receive both types of message at the same time.
When slots 14 and 15 are defined as reception slots in Basic CAN mode, received messages are stored in
slots 14 and 15 alternately.
Which type of message has been received can be checked by the RemActive bit in the CiMCTLj register.
Figure 19.19 shows the Slots 14 and 15 Operation in Basic CAN Mode.
Figure 19.19 Slots 14 and 15 Operation in Basic CAN Mode
When using Basic CAN mode, note the following points.
(1) Setting of Basic CAN mode has to be done in CAN reset/initialization mode.
(2) Select the same ID for slots 14 and 15. Also, setting of registers CiLMAR and CiLMBR has to be the
same.
(3) Define slots 14 and 15 as reception slot only.
(4) There is no protection available against message overwrite. A message can be overwritten by a new
message.
(5) Slots 0 to 13 can be used in the same way as in normal CAN operation mode.
Slot 14
Slot 15
Msg n Msg n+1 Msg n+2
Empty
Locked (empty) Locked (empty)
Msg n
Locked
Msg n + 1
Msg n+2
(Msg n lost)
Locked (Msg n+1
)
(Msg n)
Comentários a estes Manuais