msm9225 Oki Semiconductor, msm9225 Datasheet - Page 59

• Manufacturer Part Number: msm9225
• Description: Can Controller Area Network Controller
• Manufacturer: Oki Semiconductor

7. Baud rate control function
(1) Prescaler
(2) Bit timing
• Sync segment
• Prop segment
• Phase segments
• SJW
¡ Semiconductor
The MSM9225 has a prescaler that divides the frequency of the system clock. The prescaler
divides the system clock frequency by a factor of 1 to 64 to generate clock CK
Time Logic)
The timing for 1 data bit is defined below.
(Synchronization segment)
(Phase Buffer segment)
(Phase buffer segment)
(Propagation segment)
Phase segment 1
Phase segment 2
CAN protocol
Sync segment
Prop segment
Definition for CAN protocol
Definition for MSM9225
Sync segment
Sync segment
: This is the first segment for bit synchronization.
: This segment absorbs the delay of the output buffer, CAN bus and input
: These segments compesate for deviations in the data bit timing.
: Abbreviation of reSynchronization Jump Width. These bits set the bit
buffer.
Set the prop segment so that Ack will be returned by the start of phase
segment 1.
Prop segment time (output buffer delay) + (CAN bus delay) + (input
buffer delay)
The larger these segments, the greater the allowable deviation, however
communication speed will decrease.
synchronization range.
Segment name
Prop segment
SJW1
(Synchronization segment)
(Time segment)
(Time segment)
SJW2 protocol
Sync segment
MSM9225
Bit time
Bit time
TSEG1
TSEG2
SJW1
Phase segment 1
TSEG1
Sampling point
Sampling point
TSEG2
Phase segment 2
Segment length (BTL)
1 to 16, programmable
1 to 4, programmable
1 to 8, programmable
1 to 4, programmable
SJW2
1
BTL
. (BTL: Bit
MSM9225
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