Reception And Transmission - Renesas M16C/60 Series Hardware Manual

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M16C/6N5 Group

Reception and Transmission

Configuration of CAN Reception and Transmission Mode
Table 1.19.3 shows configuration of CAN reception and transmission mode.
Table 1.19.3 Configuration of CAN Reception and Transmission Mode
TrmReq RecReq
0 0
0 1
1 0
1 0
0 1
RemActive bit, RspLock bit: C0MCTLj register's bits (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 C0MCTLj registers (j = 0 to 15) to
"00 ".
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(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 C0MCTLj registers to "00
(2) Set the TrmReq bit to "0" (not transmission slot) before rewriting a transmission slot.
(3) A transmission slot should not be rewritten when the TrmActive bit in the C0MCTLj register is "1"
(transmitting).
If it is rewritten, an indeterminate data will be transmitted.
Rev.1.00 2003.05.30 page 224
Remote RspLock
Communication environment configuration mode: configure the commu-
nication mode of the slot.
0 0 Configured as a reception slot for a data frame.
1 0 Configured as a transmission slot for a remote frame. (At this time the
RemActive bit is "1".)
After completion of transmission, this functions as a reception slot for a
data frame. (At this time the RemActive bit is "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.
0 0 Configured as a transmission slot for a data frame.
1 1/0 Configured as a reception slot for a remote frame. (At this time the
RemActive bit is "1".)
After completion of reception, this functions as a transmission slot for a
data frame. (At this time the RemActive bit is "0".)
However, transmission does not start as long as RspLock bit remains "1";
thus no automatic remote frame response.
Response (transmission) starts when RspLock bit is set to "0".
Communication mode of the slot
CAN Module
".
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