SAM4L Datasheet, PDF (597/1185 Pages) ATMEL Corporation – ATSAM ARM-based Flash MCU

ATSAM4L4/L2
Figure 24-32. Frame Slot Mode with Automatic Checksum
Frame slot = TFrame_Maximum
Frame
Header
Response
space
Data3
Response
Inter-
frame
space
Break
TXRDY
Write
LINID
Write
THR
LINTC
Synch
Protected
Identifier
Data 1
Data N-1
Data N
Checksum
Frame Slot Mode Frame Slot Mode
Disabled
Enabled
Data 1
Data 2
Data 3
Data N
The minimum frame slot size is determined by TFrame_Maximum, and calculated below (all val-
ues in bit periods):
• THeader_Nominal = 34
• TFrame_Maximum = 1.4 x (THeader_Nominal + TResponse_Nominal + 1)
Note: The term “+1” leads to an integer result for TFrame_Max (LIN Specification 1.3)
If the Checksum is sent (CHKDIS=0):
• TResponse_Nominal = 10 x (NData + 1)
• TFrame_Maximum = 1.4 x (34 + 10 x (DLC + 1 + 1) + 1)
• TFrame_Maximum = 77 + 14 x DLC
If the Checksum is not sent (CHKDIS=1):
• TResponse_Nominal = 10 x NData
• TFrame_Maximum = 1.4 x (34 + 10 x (DLC + 1) + 1)
• TFrame_Maximum = 63 + 14 x DLC
24.6.10.13
LIN Errors
This section describes the errors generated in LIN mode, and the coresponding error bits in
CSR. The error bits are cleared by writing a one to CR.RSTSTA. An interrupt request is gener-
ated if the corresponding bit in the Interrupt Mask Register (IMR) is set. This bit is set by writing
a one to the corresponding bit in the Interrupt Enable Register (IER).
• Header Time-out Error (CSR.LINHTE)
– This error is generated if the Header is not received within the time specified by
THeader_Maximum.
• Sync Tolerance Error (CSR.LINSTE)
– This error is generated if the synchronization baudrate deviation is larger than the
maximum tolerance, FTol_Unsync ±15%. The synchronization procedure is aborted.
• Slave Not Responding Error (CSR.LINSNRE)
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