Rainbow Electronics ATmega64C1 - Manual (Page 216)

216
7647A–AVR–02/08
ATmega32/64/M1/C1
ever, the LIN slave application has to solve this as:
- known identifier (parity bits corrupted),
- or corrupted identifier to be ignored,
- or new identifier.
• LSERR = LIN Synchronization ERRor.
A LIN synchronization error will be flagged if a slave detects the edges of the SYNCH field
outside the given tolerance.
• LFERR = LIN Framing ERRor.
A framing error will be flagged if dominant STOP bit is sampled.
Same function in UART mode.
• LTOERR = LIN Time Out ERRor.
A time-out error will be flagged if the MESSAGE frame is not fully completed within the max-
imum length T
Frame_Maximum
by any slave task upon transmission of the SYNCH and IDENTI-
FIER fields (see Section 17.5.10 “Frame Time Out” on page 216 ).
• LOVERR = LIN OVerrun ERRor.
Overrun error will be flagged if a new command (other than LIN Abort) is entered while ‘Busy
signal’ is present.
In UART mode, an overrun error will be flagged if a received byte overwrites the byte stored
in the serial input buffer.
• LABORT
LIN abort transfer reflects a previous LIN Abort command (LCMD[2..0] = 000) while ‘Busy
signal’ is present.
After each LIN error, the LIN controller stops its previous activity and returns to its withdrawal
mode (LCMD[2..0] = 000
b
) as illustrated in Figure 17-11 on page 215 .
Writing 1 in LERR of LINSIR register resets LERR bit and all the bits of the LINERR register.
17.5.10 Frame Time Out
According to the LIN protocol, a frame time-out error is flagged if: T
Frame
> T
Frame_Maximum
. This
feature is implemented in the LIN/UART controller.
Figure 17-12. LIN timing and frame time-out
17.5.11 Break-in-data
According to the LIN protocol, the LIN/UART controller can detect the BREAK/SYNC field
sequence even if the break is partially superimposed with a byte of the response. When a
BREAK
Field
SYNC
Field
CHECKSUM
Field
DATA-0
Field Field
IDENTIFIER
PROTECTED
DATA-n
Field
T
Response
T
Header
T
Frame
T
Header_Maximum
T
Header_Maximum +
T
Response_Maximum
1.4 x
T
Header_Nominal
1.4 x
T
Response_Nominal
T
Response_Maximum
T
Frame_Maximum
=
=
=
Maximun before Time-out
T
Header_Nominal
T
Header_Nominal +
T
Response_Nominal
34 x
T
Bit
10 ( Number_of_Data + 1 ) x
T
Bit
T
Response_Nominal
T
Frame_Nominal
=
=
=
Nominal