SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
As CNF is reusing NSF3V logic for the core functionality, most of the programming model follows that of NSF3V (see Section 9.3.3.3.3).
NSF3V in YUV420UV mode has the following constraints:
When the optional chroma downsampling is enabled, the CNF core gets half of the width and half of the height. In addition, CDS/CUS stages need to work with downsampled chroma having minimal height of 2 lines.
In addition, the following constraints exist:
The image width/height programmed in the ISP-top level is to be consistent with the image width/height programmed in the CNF-core (NSF3V reuse) register space, and should be 1/2 of the resizer output when CDS is enabled. Table 9-194 shows some example configurations.
| Resizer output width | Resizer output height | CDS | ISP-top CNF image width = CNF-core image width | ISP-top CNF image width = CNF-core image width | CNF input/output U/V data points |
|---|---|---|---|---|---|
| 1920 | 1080 | OFF | 1920 | 1080 | 960 x 540 x 2 |
| 1920 | 1080 | ON | 960 | 540 | 480 x 270 x 2 |
The following NSF3V features are to be preserved: