CAN 2.0B Controller Module
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
16-29
16.7.6
Prescaler Divide Register (PRESDIV)
Table 16-16. CANCTRL1 Bit Descriptions
Bits
Name
Description
0:7
CANCTRL0
See
8
SAMP
Sampling mode. The SAMP bit determines whether the TouCAN module will sample each
received bit one time or three times to determine its value.
0 One sample, taken at the end of phase buffer segment one, is used to determine the value
of the received bit.
1 Three samples are used to determine the value of the received bit. The samples are taken
at the normal sample point and at the two preceding periods of the S-clock.
9
—
Reserved
10
TSYNC
Timer synchronize mode. The TSYNC bit enables the mechanism that resets the
free-running timer each time a message is received in message buffer zero. This feature
provides the means to synchronize multiple TouCAN stations with a special “SYNC”
message (global network time).
0 Timer synchronization disabled.
1 Timer synchronization enabled.
Note: there can be a bit clock skew of four to five counts between different TouCAN modules
that are using this feature on the same network.
11
LBUF
Lowest buffer transmitted first. The LBUF bit defines the transmit-first scheme.
0 Message buffer with lowest ID is transmitted first.
1 Lowest numbered buffer is transmitted first.
12
—
Reserved
13:15
PROPSEG
Propagation segment time. PROPSEG defines the length of the propagation segment in the
bit time. The valid programmed values are zero to seven. The propagation segment time is
calculated as follows:
Propagation Segment Time = (P 1) Time Quanta
where
1 Time Quantum = 1 Serial Clock (S-Clock) Period
MSB
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
LSB
15
Field
PRESDIV
CANCTRL2
SRESET
0000_0000_0000_0000
Addr
0x30 7088 (PRESDIV_A); 0x30 7488 (PRESDIV_B); 0x30 7888 (PRESDIV_C)
Figure 16-13. Prescaler Divide Register
Summary of Contents for MPC561
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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...
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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...