M16CSLASH29 datasheet(331/499 Pages) RENESAS

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17. CAN Module

page 307

17.6 BasicCAN Mode

When the BasicCAN bit in the C0CTLR register is set to 1 (Basic CAN mode enabled), slots 14 and 15

correspond to Basic CAN mode. During normal operations, individual slots can select either data frame or

remote frame by CPU setting. However, in Basic CAN mode, both frames can be selected.

When slots 14 and 15 are defined as reception slots in Basic CAN mode, received messages are stored in

slots 14 and 15 alternately.

The received message data format can be determined by the RemActive bit in the C0MCTLj register (j = 0

to 15).

Figure 17.24

shows the operation of slots 14 and 15 in Basic CAN mode.

Figure 17.24 Operation of Slots 14 and 15 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 the C0LMAR and C0LMBR register 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 operating mode.

Slot 14

Slot 15

Msg n

Msg n+1

Msg n+2

Empty

Locked (empty)

Msg n

Locked

Msg n + 1

Msg n+2 (Msg n lost)

Locked (Msg n+1)

(Msg n)

M16C/29 Datasheet(PDF) 331 Page - Renesas Technology Corp