AT32UC3A3256S_1 Datasheet, PDF (578/961 Pages) ATMEL Corporation – AVR32 32-Bit Microcontroller

AT32UC3A3
26.7.9.12
Frame Slot Mode
This mode is useful only for Master nodes. It respects the following rule: each frame slot shall be
longer than or equal to TFrame_Maximum.
If the Frame Slot Mode is enabled (FSDIS = 0) and a frame transfer has been completed, the
TXRDY flag is set again only after TFrame_Maximum delay, from the start of frame. So the Mas-
ter node cannot send a new header if the frame slot duration of the previous frame is inferior to
TFrame_Maximum.
If the Frame Slot Mode is disabled (FDIS = 1) and a frame transfer has been completed, the
TXRDY flag is set again immediately.
The TFrame_Maximum is calculated as below:
If the Checksum is sent (CHKDIS = 0):
• THeader_Nominal = 34 x TBit
• TResponse_Nominal = 10 x (NData + 1) x TBit
• TFrame_Maximum = 1.4 x (THeader_Nominal + TResponse_Nominal + 1)^(Note:)
• TFrame_Maximum = 1.4 x (34 + 10 x (DLC + 1 + 1) + 1) x TBIT
• TFrame_Maximum = (77 + 14 x DLC) x TBIT
If the Checksum is not sent (CHKDIS = 1):
• THeader_Nominal = 34 x TBit
• TResponse_Nominal = 10 x NData x TBit
• TFrame_Maximum = 1.4 x (THeader_Nominal + TResponse_Nominal + 1^(Note:))
• TFrame_Maximum = 1.4 x (34 + 10 x (DLC + 1) + 1) x TBIT
• TFrame_Maximum = (63 + 14 x DLC) x TBIT
Note: The term “+1” leads to an integer result for TFrame_Max (LIN Specification 1.3)
Figure 26-45. Frame Slot Mode
Header
Frame slot = TFrame_Maximum
Frame
Response
space
Data3
Response
Inter-
frame
space
Break
TXRDY
Write
LINID
Write
THR
LINTC
Synch
Protected
Identifier
Data 1
Data 1
Data 2
Data 3
Data N-1
Data N
Checksum
Data N
Frame Slot Mode Frame Slot Mode
Disabled
Enabled
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