PXD10RM Datasheet, PDF (689/1332 Pages) Freescale Semiconductor, Inc – PXD10 Microcontroller

there is no message on the bus, it counts using the previously programmed baud rate. During Freeze Mode,
the timer is not incremented.
The timer value is captured at the beginning of the identifier field of any frame 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.
Writing to the timer is an indirect operation. The data is first written to an auxiliary register and then an
internal request/acknowledge procedure across clock domains is executed. All this is transparent to the
user, except for the fact that the data will take some time to be actually written to the register. If desired,
software can poll the register to discover when the data was actually written.
Base + 0x0008
0
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15
R₀
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
W
RESET: ₀
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
R
TIMER
W
RESET: ₀
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 18-7. Free Running Timer (TIMER)
18.3.4.4 Rx Global Mask (RXGMASK)
This register is provided for legacy support and for low cost MCUs that do not have the individual masking
per Message Buffer feature. For MCUs supporting individual masks per MB, setting the BCC bit in MCR
causes the RXGMASK Register to have no effect on the module operation. For MCUs not supporting
individual masks per MB, this register is always effective.
RXGMASK is used as acceptance mask for all Rx MBs, excluding MBs 14–15, which have individual
mask registers. When the FEN bit in MCR is set (FIFO enabled), the RXGMASK also applies to all
elements of the ID filter table, except elements 6-7, which have individual masks.
The contents of this register must be programmed while the module is in Freeze Mode, and must not be
modified when the module is transmitting or receiving frames.
Freescale Semiconductor
PXD10 Microcontroller Reference Manual, Rev. 1
Preliminary—Subject to Change Without Notice
18-19