
50.4.4 Free Running Timer (CANx_TIMER)
This register represents a 16-bit free running counter that can be read and written by the
CPU. The timer starts from 0x0 after Reset, counts linearly to 0xFFFF, and wraps around.
When the TIMER_SRC in CAN_CTRL2 register is asserted, the timer is continuously
incremented by an external time tick. The time tick must be synchronous to the
Peripheral Clock, with a minimum pulse width of one clock cycle.
When the TIMER_SRC bit in CAN_CTRL2 register is negated, the timer is incremented
by the CAN 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 timer is not incremented during Disable, Stop and Freeze modes.
The timer value is captured when the second bit of the identifier field of any frame is on
the CAN bus. This captured value is written into the Time Stamp entry in a message
buffer after a successful reception or transmission of a message.
If bit CAN_CTRL1[TSYN] is asserted, the Timer is reset whenever a message is
received in the first available Mailbox, according to CAN_CTRL2[RFFN] setting.
The CPU can write to this register anytime. However, if the write occurs at the same time
that the Timer is being reset by a reception in the first Mailbox, then the write value is
discarded.
Reading this register affects the Mailbox Unlocking procedure, see Section "Mailbox
Lock Mechanism".
Address: Base a 8h offset
Bit 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
8
7
6
5
4
3
2
1
0
R
W
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
CANx_TIMER field descriptions
Field
Description
31–16
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
TIMER
Timer Value
Contains the free-running counter value.
Chapter 50 CAN (FlexCAN)
Kinetis KE1xF Sub-Family Reference Manual, Rev. 4, 06/2019
NXP Semiconductors
1401
Summary of Contents for KE1xF Series
Page 2: ...Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 2 NXP Semiconductors...
Page 138: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 138 NXP Semiconductors...
Page 360: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 360 NXP Semiconductors...
Page 490: ...Interrupts Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 490 NXP Semiconductors...
Page 562: ...Boot Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 562 NXP Semiconductors...
Page 706: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 706 NXP Semiconductors...
Page 736: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 736 NXP Semiconductors...
Page 866: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 866 NXP Semiconductors...
Page 1164: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 1164 NXP Semiconductors...
Page 1178: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 1178 NXP Semiconductors...
Page 1380: ...Usage Guide Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 1380 NXP Semiconductors...
Page 1472: ...Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 1472 NXP Semiconductors...
Page 1482: ...Kinetis KE1xF Sub Family Reference Manual Rev 4 06 2019 1482 NXP Semiconductors...