SPRUIN7C March 2020 – March 2024 TMS320F280021 , TMS320F280021-Q1 , TMS320F280023 , TMS320F280023-Q1 , TMS320F280023C , TMS320F280025 , TMS320F280025-Q1 , TMS320F280025C , TMS320F280025C-Q1
The CAN module provides three DMA trigger outputs, one for each of the three Interface Registers IF1, IF2 and IF3. These can be enabled using the DE1, DE2, and DE3 bits in the CAN_CTL register.
The Update of IF1 and IF2 registers is initiated by a write access to the IF1 and IF2 Command registers, respectively. Once enabled, setting the DMAactive bit in the IF1CMD or IF2CMD registers cause a DMA request the next time the corresponding interface becomes available.
The IF3 registers content can be automatically updated on reception of CAN messages in message objects which are programmed for automatic IF3 update. That is, when IF3 DMA requests are enabled, all IF3 updates trigger a DMA request.
When a DCAN internal IFx update is complete, a DMA request is activated and stays active until the first access to one of the relevant IFx registers; that is, DMA requests are cleared after the first read or write access to an IF register set.