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CHAPTER 11 FCAN CONTROLLER
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User’s Manual U14492EJ3V0UD
11.14 Ensuring Data Consistency
When the CPU reads data from CAN message buffers, it is essential for the read data to be consistent.
Two methods are used to ensure data consistency: sequential data read and burst read mode.
11.14.1 Sequential data read
When the CPU performs sequential access of a CAN message buffer, data is read from the buffer in the order
shown in Figure 11-47 below.
Only the FCAN can set the M_STATn register’s DN bit (to 1) and only the CPU can clear it (to 0), so during the
read operation the CPU must be able to check whether or not any new data has been stored in the message buffer.
Figure 11-47. Sequential Data Read
Read CPU
End of CPU’s read operation
Yes
DN = 0
(M_STATn)
No
DN = 0
(M_STATn)
Read data from
message buffer
Remark
n = 00 to 31