NXP Semiconductors MWCT101 S Series, Reference Manual

Page: 1691 / 1761

NOTE
There is no remote frame in the CAN FD format. The RTR bit
is replaced by a fixed dominant RRS bit. FlexCAN receives and
transmits remote frames in the Classical CAN format.
49.5.9.5 Overload frames
FlexCAN does transmit overload frames when the following conditions are detected on
the CAN bus:
• Detection of a dominant bit in the first/second bit of Intermission
• Detection of a dominant bit at the 7th bit (last) of End of Frame field (Rx frames)
• Detection of a dominant bit at the 8th bit (last) of Error Frame Delimiter or Overload
Frame Delimiter
49.5.9.6 Time stamp
The value of the free running timer is sampled at the beginning of the Identifier field on
the CAN bus, and is stored at the end of move-in in the TIME STAMP field, providing
network behavior with respect to time.
When CTRL2[TIMER_SRC] is asserted, the free running timer is continuously clocked
by an external time tick.
When CTRL2[TIMER_SRC] is negated, the free running timer is clocked by the
FlexCAN bit-clock, which defines the baud rate on the CAN bus. During a message
transmission/reception, it increments by one for each bit that is received or transmitted.
When there is no message on the bus, it counts using the previously programmed baud
rate.
The free running timer is not incremented during Disable, Stop, and Freeze modes. It can
be reset upon a specific frame reception, enabling network time synchronization. See the
TSYN description in Control 1 register (CTRL1).
Chapter 49 FlexCAN
MWCT101xS Series Reference Manual, Rev. 3, 07/2019
NXP Semiconductors 1691