SPRUHZ7K August 2015 – April 2024 AM5706 , AM5708 , AM5716 , AM5718 , AM5718-HIREL
The DCAN provides a parity check mechanism to ensure data integrity of message RAM data. For each word (32 bits) in message RAM, one parity bit will be calculated. The formation of the different words is according to the message RAM representation in RDA mode, see Section 24.10.4.11.4, Message RAM Representation in Direct Access Mode.
Parity information is stored in the message RAM on write accesses and will be checked against the stored parity bit from message RAM on read accesses.
The Parity check functionality can be enabled or disabled by DCAN_CTL[13:10] PMD bit field.
In case of disabled parity check, the parity bits in message RAM will be left unchanged on write access to data area and no check will be done on read access.
If parity checking is enabled, parity bits will be automatically generated and checked by the DCAN. The parity bits could be read in debug/suspend mode (see Section 24.10.4.11.3, Message RAM Representation in Debug/Suspend Mode) or in RDA mode (see Section 24.10.4.11.4, Message RAM Representation in Direct Access Mode). However, direct write access to the parity bits is only possible in this two modes with parity check disabled.
A parity bit will be set, if the modulo-2-sum of the data bits is 1. This definition is equivalent to: The parity bit will be set, if the number of 1 bits in the data is odd.
DCAN is configured to even parity by the design.