842
11054A–ATARM–27-Jul-11
SAM9X25
842
11054A–ATARM–27-Jul-11
SAM9X25
39.7.8.12
Checksum
The last field of a frame is the checksum. The checksum contains the inverted 8- bit sum with
carry, over all data bytes or all data bytes and the protected identifier. Checksum calculation
over the data bytes only is called classic checksum and it is used for communication with LIN 1.3
slaves. Checksum calculation over the data bytes and the protected identifier byte is called
enhanced checksum and it is used for communication with LIN 2.0 slaves.
The USART can be configured to:
• Send/Check an Enhanced checksum automatically (CHKDIS = 0 & CHKTYP = 0)
• Send/Check a Classic checksum automatically (CHKDIS = 0 & CHKTYP = 1)
• Not send/check a checksum (CHKDIS = 1)
This configuration is made by the Checksum Type (CHKTYP) and Checksum Disable (CHKDIS)
fields of the LIN Mode register (US_LINMR).
If the checksum feature is disabled, the user can send it manually all the same, by considering
the checksum as a normal data byte and by adding 1 to the response data length (see
).
Summary of Contents for SAM9X25
Page 26: ...26 11054A ATARM 27 Jul 11 SAM9X25...
Page 138: ...138 11054A ATARM 27 Jul 11 SAM9X25 138 11054A ATARM 27 Jul 11 SAM9X25...
Page 162: ...162 11054A ATARM 27 Jul 11 SAM9X25 162 11054A ATARM 27 Jul 11 SAM9X25...
Page 216: ...216 11054A ATARM 27 Jul 11 SAM9X25 216 11054A ATARM 27 Jul 11 SAM9X25...
Page 266: ...266 11054A ATARM 27 Jul 11 SAM9X25 266 11054A ATARM 27 Jul 11 SAM9X25...
Page 330: ...330 11054A ATARM 27 Jul 11 SAM9X25 330 11054A ATARM 27 Jul 11 SAM9X25...
Page 374: ...374 11054A ATARM 27 Jul 11 SAM9X25...
Page 468: ...468 11054A ATARM 27 Jul 11 SAM9X25 468 11054A ATARM 27 Jul 11 SAM9X25...
Page 532: ...532 11054A ATARM 27 Jul 11 SAM9X25 532 11054A ATARM 27 Jul 11 SAM9X25...
Page 692: ...692 11054A ATARM 27 Jul 11 SAM9X25 692 11054A ATARM 27 Jul 11 SAM9X25...
Page 777: ...777 11054A ATARM 27 Jul 11 SAM9X25 777 11054A ATARM 27 Jul 11 SAM9X25...
Page 886: ...886 11054A ATARM 27 Jul 11 SAM9X25 886 11054A ATARM 27 Jul 11 SAM9X25...
Page 962: ...962 11054A ATARM 27 Jul 11 SAM9X25 962 11054A ATARM 27 Jul 11 SAM9X25...
Page 1036: ...1036 11054A ATARM 27 Jul 11 SAM9X25 1036 11054A ATARM 27 Jul 11 SAM9X25...
Page 1128: ...1128 11054A ATARM 27 Jul 11 SAM9X25 1128 11054A ATARM 27 Jul 11 SAM9X25...
Page 1130: ...1130 11054A ATARM 27 Jul 11 SAM9X25...
Page 1132: ...1132 11054A ATARM 27 Jul 11 SAM9X25...
Page 1144: ...xii 11054A ATARM 27 Jul 11 SAM9X25...