M16C6NK Datasheet, PDF (261/404 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

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M16C/6N Group (M16C/6NK, M16C/6NM)
19. CAN Module
19.15 Reception and Transmission
Table 19.3 shows configuration of CAN reception and transmission mode.
Table 19.3 Configuration of CAN Reception and Transmission Mode
TrmReq RecReq Remote RspLock
Communication Mode of Slot
0
0
-
- Communication environment configuration mode:
configure the communication mode of the slot.
0
1
0
0 Configured as a reception slot for a data frame.
1
0
1
0 Configured as a transmission slot for a remote frame.
(At this time the RemActive = 1.)
After completion of transmission, this functions as a reception
slot for a data frame. (At this time the RemActive = 0.)
However, when an ID that matches on the CAN bus is detected
before remote frame transmission, this immediately functions
as a reception slot for a data frame.
1
0
0
0 Configured as a transmission slot for a data frame.
0
1
1
1/0 Configured as a reception slot for a remote frame.
(At this time the RemActive = 1.)
After completion of reception, this functions as a transmission
slot for a data frame. (At this time the RemActive = 0.)
However, transmission does not start as long as RspLock bit
remains “1”; thus no automatic response.
Response (transmission) starts when the RspLock bit is set to “0”.
TrmReq, RecReq, Remote, RspLock, RemActive, RspLock: Bits in CiMCTLj register (i = 0, 1, j = 0 to 15)
When configuring a slot as a reception slot, note the following points.
(1) Before configuring a slot as a reception slot, be sure to set the CiMCTLj register to “00h”.
(2) A received message is stored in a slot that matches the condition first according to the result of reception
mode configuration and acceptance filtering operation. Upon deciding in which slot to store, the smaller
the number of the slot is, the higher priority it has.
(3) In normal CAN operation mode, when a CAN module transmits a message of which ID matches, the
CAN module never receives the transmitted data. In loop back mode, however, the CAN module
receives back the transmitted data. In this case, the module does not return ACK.
When configuring a slot as a transmission slot, note the following points.
(1) Before configuring a slot as a transmission slot, be sure to set the CiMCTLj registers to “00h”.
(2) Set the TrmReq bit in the CiMCTLj register to “0” (not transmission slot) before rewriting a transmission slot.
(3) A transmission slot should not be rewritten when the TrmActive bit in the CiMCTLj register is “1”
(transmitting).
If it is rewritten, an indeterminate data will be transmitted.
Rev.2.00 Nov 28, 2005 page 243 of 378
REJ09B0124-0200