Datasheet

V850ES/JG3-H, V850ES/JH3-H CHAPTER 20 CAN CONTROLLER
R01UH0042EJ0500 Rev.5.00 Page 983 of 1513
Aug 12, 2011
20.9.2 Reading reception data
If it is necessary to consistently read data from the CAN message buffer by software, follow the recommended
procedures shown in Figures 20-49 and 20-50.
While receiving a message, the CAN module sets the C0MCTRLm.DN bit two times, at the beginning of the processing
to store data in the message buffer and at the end of this storing processing. During this storing processing, the
C0MCTRLm.MUC bit of the message buffer is set (1) (refer to Figure 20-29).
Before the data is completely stored, the receive history list is written. During this data storing period (MUC bit = 1), the
CPU is prohibited from rewriting the C0MCTRLm.RDY bit of the message buffer in which the data is to be stored.
Completion of this data storing processing may be delayed by a CPU’s access to any message buffer.
Remark m = 0 to 31
Figure 20-29. DN and MUC Bit Setting Period (in Standard ID Format)
SOF
(1)
ID
IDE RTR R0
DLC DATA0-DATA7 CRC ACK EOF
CAN standard
ID format
(11) (1)(1) (1) (4) (0-64) (16) (2)
Recessive
Dominant
DN bit
MUC bit
Message stored
DATA, DLC, ID → Message buffer
(7)
The DN bit is set (1) and the
MUC bit is cleared (0) at the
same time.
C0INTS.CINTS1
bit
The DN and MUC bits are
set (1) at the same time.
IFS
INTC0REC
signal
Operation of CAN controller