RM0046 Boot Assist Module (BAM)
Doc ID 16912 Rev 5 827/936
Figure 492. BAM rate measurement flow during FlexCAN boot
Start
NO
ERROR
Follow normal
CAN boot protocol
Wait CAN_RX == 1
Wait CAN_RX == 0
Stop STM
Read elapsed time
Calculate baud rate
Baud rate configuration
These steps are
executed 4 times
to work with FlexCAN module.
CAN_RX pin is configured
FlexCAN:
– is configured with calculated baud
– is enabled on the network
There is a glitch if
measured time < CAN_GLITCH_WIDTH
Read STM.
measured time = STM value
CAN_RX == 1
CAN_RX == 0
Glitch?
CAN_0_RX pin
configured as
GPIO input
YES
NO
NO
YES
Start STM
If CAN is connected,
CAN_RX should be at high level
CAN_RX == 1
Wait for the first
recessive (HIGH) bit