2 data length in lin 1.3, 3 data length in rx response, 4 data length in tx response – Rainbow Electronics ATmega64M1 User Manual

Page 212

212

8209A–AVR–08/09

ATmega16M1/32M1/64M1

21.5.7.2

Data Length in LIN 1.3

• LRXDL and LTXDL fields are both hardware updated before setting LIDOK by decoding the

data length code contained in the received PROTECTED IDENTIFIER (LRXDL = LTXDL).

• Via the above mechanism, a length of 0 or >8 is not possible.

21.5.7.3

Data Length in Rx Response

Figure 21-9. LIN2.1 - Rx Response - No error

• The user initializes LRXDL field before setting the Rx Response command,

• After setting the Rx Response command, LTXDL is reset by hardware,

• LRXDL field will remain unchanged during Rx (during busy signal),

• LTXDL field will count the number of received bytes (during busy signal),

• If an error occurs, Rx stops, the corresponding error flag is set and LTXDL will give the

number of received bytes without error,

• If no error occurs, LRXOK is set after the reception of the CHECKSUM, LRXDL will be

unchanged (and LTXDL = LRXDL).

21.5.7.4

Data Length in Tx Response

Figure 21-10. LIN1.3 - Tx Response - No error

DATA-0

DATA-1

DATA-2

DATA-3

CHECKSUM

LINDLR=0x?4

LCMD2..0=000

LIN bus

LRXDL (*)

LBUSY

LTXDL (*)

Byte

LIDOK

LRXOK

LCMD=Rx Response

(*) : LRXDL & LTXDL updated by user