SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
During Semi-CPU mode, no DMA request is generated by CRC controller. Therefore, no DMA channel is allocated to update CRC Value Register. CPU should not read from CRC Value Register in semi-CPU mode as it contains stale value. Note that no signature verification is performed at all during this mode. Similar to AUTO mode, either by hardware or by software DMA request can be used as a trigger for data patterns transfer. Figure 12-506 illustrates the DMA setup using semi-CPU mode with hardware timer trigger.
CRC Mode | DMA Request | Pattern Counter | Sector Counter | Timeout Counter |
---|---|---|---|---|
AUTO | Active | Active | Active | Active |
Semi-CPU | Inactive | Active | Active | Active |
Full CPU | Inactive | Inactive | Inactive | Inactive |