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8XC196K x , J x , CA USER'S MANUAL
CAN_MSG x CON1
x = 1–15 (87C196CA)
The CAN message object x control 1 (CAN_MSG x CON1) register indicates whether a message
object has been updated, whether a message has been overwritten, whether the CPU is updating the
message, and whether a transmission or reception is pending.
This register consists of four bit-pairs — the most-significant bit of each pair is in true form and the
least-significant bit is in complement form. This format allows software to set or clear any bit with a
single write operation, without affecting the remaining bits.
7
87C196CA
RMTPND
Bit
Bit
Number
Mnemonic
7:6
RMTPND
5:4
TX_REQ
Figure 12-15. CAN Message Object x Control 1 (CAN_MSG x CON1) Register
12-26
RMTPND
TX_REQ
TX_REQ
Remote Request Pending
Receive message objects do not use this bit-pair.
The CAN controller sets this bit-pair to indicate that a remote frame has
requested the transmission of a transmit message object. If the CPUUPD
bit-pair is clear, the CAN controller transmits the message object, then
clears RMTPND. Setting RMTPND does not cause a transmission; it only
indicates that a transmission is pending.
bit 7 bit 6
0
1
no pending request
1
0
a remote request is pending
Transmission Request
Set this bit-pair to cause a receive message object to transmit a remote
frame (a request for transmission) or to cause a transmit object to transmit
a data frame. Read this bit-pair to determine whether a transmission is in
progress.
bit 5 bit 4
0
1
no pending request; no transmission in progress
1
0
transmission request; transmission in progress
Address:
1E x 1H ( x = 1–F)
Reset State:
Unchanged
MSGLST
MSGLST
NEWDAT
CPUUPD
CPUUPD
Function
0
NEWDAT
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