K60P100M100SF2RM Datasheet, PDF (1338/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Memory Map/Register Definition
48.3.14 Control 2 Register (CANx_CTRL2)
This register contains control bits for CAN errors, FIFO features, and mode selection.
Addresses: CAN0_CTRL2 is 4002_4000h base + 34h offset = 4002_4034h
CAN1_CTRL2 is 400A_4000h base + 34h offset = 400A_4034h
Bit 31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
R
0
W0
RFFN
TASD
RRS
Reset 0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
Bit 15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R
0
W
Reset 0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
CANx_CTRL2 field descriptions
Field
31
Reserved
30–29
Reserved
28
WRMFRZ
This field is reserved.
Description
This read-only field is reserved and always has the value zero.
Write-Access to Memory in Freeze mode
Enable unrestricted write access to FlexCAN memory in Freeze mode. This bit can only be written in
Freeze mode and has no effect out of Freeze mode.
27–24
RFFN
0 Maintain the write access restrictions.
1 Enable unrestricted write access to FlexCAN memory.
Number of Rx FIFO Filters
This 4-bit field defines the number of Rx FIFO filters, as shown in the following table. The maximum
selectable number of filters is determined by the MCU. This field can only be written in Freeze mode as it
is blocked by hardware in other modes. This field must not be programmed with values that make the
number of Message Buffers occupied by Rx FIFO and ID Filter exceed the number of Mailboxes present,
defined by MCR[MAXMB].
NOTE: Each group of eight filters occupies a memory space equivalent to two Message Buffers which
means that the more filters are implemented the less Mailboxes will be available.
Considering that the Rx FIFO occupies the memory space originally reserved for MB0-5, RFFN
should be programmed with a value correponding to a number of filters not greater than the
number of available memory words which can be calculated as follows:
(SETUP_MB - 6) x 4
where SETUP_MB is the least between NUMBER_OF_MB and MAXMB.
Table continues on the next page...
1338
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.