SPRUJ79 November 2024 F29H850TU
WADI raises RTDMA request based on the events occurring in the WADI block or SSS. WADI has a RTDMA mechanism that has only one RTDMA request and corresponding RTDMA ACK. Hence, it is expected that software configuring RTDMA action knows the range it needs to configure and change WADI settings or operational registers. To make it easier for software to affect only configurations that are affected, the feature for filtered writes is enabled. When writes are filtered, WADI instance tracks the WADI block, events, output events that has an error event and selectively allows change in that WADI block alone. Filtered writes are to the WADI blocks, event words and output events those are enabled for filtered writes.
If the filtered write is not enabled then all writes are allowed to WADI block. When Filtered write is enabled, then any writes within a window of a RTDMA request to RTDMA acknowledgment go through only if there is occurrence of the event within WADI block or event is triggered or output event was active and corresponding event was enabled for RTDMA trigger through DMATRIGEN.
For filtered writes within each WADI block there are three types of events and there are dedicated registers enabled for filtered writes. Thus the filtered access are granular based on events internal to the WADI. While the common filtered_en signal and RTDMA trigger enable, RTDMA update status, and RTDMA trigger status is applicable to entire WADI block.
In case the block needs an update regardless of any event, then the block must be left disabled for filtered writes.
If the event occurs after the RTDMA request and RTDMA write is not passed the corresponding address region yet then incoming filtered writes are exercised on the region though originally corresponding RTDMA request did not trigger the writes. Upon assertion of RTDMA acknowledgment the status of the filtered regions which are written is updated to the DMASTSUPDATE. Note DMASTSUPDATE is reserved for filtered writes hence regions unfiltered if written do not reflect here as software has way to deduce the same based on the DMAFILTWRCFG. Upon RTDMA acknowledgment the blocks which were written successfully deassert the RTDMA trigger (DMATRIGSTS).
The following describes the specific WADI registers having DMA filtered writes enabled