CAN 2.0B Controller Module
MPC561/MPC563 Reference Manual, Rev. 1.2
16-8
Freescale Semiconductor
shows mask examples for normal and extended messages. Refer to
” for more information on Rx mask registers.
16.3.3
Bit Timing
The TouCAN module uses three 8-bit registers to set up the bit timing parameters required by the CAN
protocol. Control registers one and two (CANCTRL1, CANCTRL2) contain the PROPSEG, PSEG1,
PSEG2, and the RJW fields that allow configuration of the bit timing parameters. The prescaler divide
register (PRESDIV) allows selection of the ratio used to derive the serial clock (S-clock) from the system
clock. The time quanta clock operates at the S-clock frequency.
provides examples of system
clock, CAN bit rate, and S-clock bit timing parameters, and
shows the relationship between
Table 16-6. Receive Mask Register Bit Values
Mask Bit
Values
0
The corresponding incoming ID bit is “don’t care”
1
The corresponding ID bit is checked against the incoming ID bit to see if a match exists
Table 16-7. Mask Examples for Normal/Extended Messages
Message Buffer (MB)/Mask
Base ID
ID[28:18]
IDE
Extended ID
ID[17:0]
Match
MB2
1 1 1 1 1 1 1 1 0 0 0
0
—
—
MB3
1 1 1 1 1 1 1 1 0 0 0
1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
—
MB4
0 0 0 0 0 0 1 1 1 1 1
0
—
—
MB5
0 0 0 0 0 0 1 1 1 0 1
1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
—
MB14
1 1 1 1 1 1 1 1 0 0 0
1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
—
Rx Global Mask
1 1 1 1 1 1 1 1 1 1 0
1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 1
—
Rx Message In
1 1 1 1 1 1 1 1 0 0 1
1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
3
1
1
Match for extended format (MB3).
1 1 1 1 1 1 1 1 0 0 1
0
—
2
2
2
Match for standard format (MB2).
1 1 1 1 1 1 1 1 0 0 1
1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 0
—
3
3
No match for MB3 because of ID0.
0 1 1 1 1 1 1 1 0 0 0
0
—
—
4
4
No match for MB2 because of ID28.
0 1 1 1 1 1 1 1 0 0 0
1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
—
5
5
No match for MB3 because of ID28, match for MB14.
Rx 14 Mask
0 1 1 1 1 1 1 1 1 1 1
1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0
—
Rx Message In
1 0 1 1 1 1 1 1 0 0 0
1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
—
6
6
No match for MB14 because of ID27.
0 1 1 1 1 1 1 1 0 0 0
1
0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1
14
7
7
Match for MB14.
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...