Atmel Evaluation Kit AT91SAM9M10-G45-EK AT91SAM9M10-G45-EK Data Sheet

 512

SAM9M10 [DATASHEET]

6355F–ATARM–12-Mar-13

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 Master 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)

• 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

• 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)

Frame Slot Mode

Break

Synch

Protected

Identifier

Data N

Checksum

Header

Inter-

frame

space

Response

space

Frame

Frame slot = TFrame_Maximum

Response

TXRDY

Write
US_THR

Write
US_LINID

Data 1

Data 2

Data 3

Data3

Data N-1

Data N

Frame Slot Mode

Disabled

Frame Slot Mode

Enabled

LINTC

Data 1