SPRUJ28E November 2021 – September 2024 AM68 , AM68A , TDA4AL-Q1 , TDA4VE-Q1 , TDA4VL-Q1
In order to support IO virtualization that allows control of different DISPC pipes by different hosts, the DISPC pipelines must be identifiable on the SoC system interconnect with different channel IDs. To achieve this, every read and write transaction out of the DISPC DMA is tagged with a CHANNELID. The SoC infrastructure then uses the CHANNELID to set the various parameters (address translation, priority, security, etc.) on a per-channel basis.
The LSB bit of the CHANNELID (that is, CHANNELID[0]) is always used to differentiate between the two planes when a pipe is fetching a 2-plane pixel format (for example, YUV420-NV12). When the pipeline is fetching a 1-plane pixel format, the LSB bit is always '0'. The mapping of the MSB bits of the CHANNELID is as shown in Table 12-355.
CHANNELID[m:1] | Pipeline Mapping |
---|---|
0 | VID1 |
1 | VIDL1 |
2 | VID2 |
3 | VIDL2 |
4 | WB |