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Controller Area Network (FlexCAN)
PXN20 Microcontroller Reference Manual, Rev. 1
Freescale Semiconductor
29-15
in freeze mode. Exceptions are the BOFF_MSK, ERR_MSK, TWRN_MSK, RWRN_MSK, and
BOFF_REC bits, which can be accessed at any time.
Offset: Base + 0x0004
Access: User read/write
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
R
PRESDIV
RJW
PSEG1
PSEG2
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
16
17v
18
19
20
21
22
23
24
25
26
27
28
29
30
31
R BOFF
_MSK
ERR_
MSK
CLK_
SRC
LPB
TWRN
_ MSK
RWRN
_MSK
0
0
SMP
BOFF
_REC
TSYN LBUF LOM
PROPSEG
W
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Figure 29-6. Control Register (CANx_CTRL)
Table 29-8. CANx_CTRL Field Descriptions
Bits
Description
PRESDIV
Prescaler Division Factor. Defines the ratio between the CPI clock frequency and the serial clock (SCK)
frequency. The SCK period defines the time quantum of the CAN protocol. For the reset value, the SCK
frequency is equal to the CPI clock frequency. The maximum value of this register is 0xFF, that gives a minimum
SCK frequency equal to the CPI clock frequency divided by 256. For more information, refer to
RJW
Resync Jump Width. Defines the maximum number of time quanta that a bit time can be changed by one
re-synchronization. One time quantum is equal to one SCK period. The valid programmable values are 0–3.
PSEG
Phase Segment 1. Defines the length of phase buffer segment 1 in the bit time. The valid programmable values
are 0–7.
PSEG2
Phase Segment 2. Defines the length of phase buffer segment 2 in the bit time. The valid programmable values
are 1–7.
BOFF_MSK
Bus Off Mask. Provides a mask for the bus off interrupt.
0 Bus off interrupt disabled.
1 Bus off interrupt enabled.
ERR_MSK
Error Mask. Provides a mask for the error interrupt.
0 Error interrupt disabled.
1 Error interrupt enabled.
S-clock frequency
CPI clock frequency
PRESDIV
1
+
-----------------------------------------------------
=
Resync Jump Width
RJW + 1
=
Phase Buffer Segment 1
PSEG1 + 1
Time Quanta
=
Phase Buffer Segment 2
PSEG2 + 1
Time Quanta
=
Summary of Contents for PXN2020
Page 1: ...PXN20 Microcontroller Reference Manual Devices Supported PXN2020 PXN2120 PXN20RM Rev 1 06 2011...
Page 42: ...PXN20 Microcontroller Reference Manual Rev 1 lxiv Freescale Semiconductor...
Page 64: ...Introduction PXN20 Microcontroller Reference Manual Rev 1 1 22 Freescale Semiconductor...
Page 112: ...Signal Description PXN20 Microcontroller Reference Manual Rev 1 3 44 Freescale Semiconductor...
Page 118: ...Resets PXN20 Microcontroller Reference Manual Rev 1 4 6 Freescale Semiconductor...
Page 372: ...e200z6 Core Z6 PXN20 Microcontroller Reference Manual Rev 1 13 8 Freescale Semiconductor...
Page 412: ...e200z0 Core Z0 PXN20 Microcontroller Reference Manual Rev 1 14 14 Freescale Semiconductor...
Page 821: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 Freescale Semiconductor 27 49...
Page 822: ...Media Local Bus MLB PXN20 Microcontroller Reference Manual Rev 1 27 50 Freescale Semiconductor...
Page 1376: ...Memory Map PXN20 Microcontroller Reference Manual Rev 1 A 118 Freescale Semiconductor...