[FAQ] AM62A7: What's the maximum camera resolution and frame rate supported by AM62A

There are a few limiting factors as far as the camera resolution and frame rate are concerned:

• Maximum bandwidth of the CSI-2 Rx interface: 1.5Gbps per lane for 4 lanes, with the total bandwidth being 6Gbps. When calculating total data rate from the sensor, the overhead due to blanking and CSI protocol needs to be accounted. The overhead can be roughly 10~25% depending on the sensor. For example, if a sensor produces 12-bit per pixel and 8MPixel resolution, running at 30fps, the total data rate with 20% overhead is 12*8*30*1.2=3.5Gbps. This is below the CSI-2 Rx bandwidth of 6Gbps.
• Maximum bandwidth of the ISP: 315MPixel/second according to the datasheet. This limit is the pixel rate and doesn't depend on the input data bit width.
• Maximum line width that the ISP can process: 4096.
• CPU load and DDR load: this is application dependent.

The ISP bandwidth is usually the main limiting factor. The ISP supports up to 16-bit RAW input data. When ISP runs at maximum bandwidth with 16-bit input, the total data rate is 315MPixel/second * 16-bit/Pixel = 5Gbps. This is below the 4-lane CSI-2 Rx maximum bandwidth. 

To evaluate if a camera resolution and frame rate can be supported by the AM62A, start from the simplest limiting factor:

1. The frame width must be smaller than 4096.
2. The total pixel rate must be smaller than 315MPixel/second. For example, a 5MP and 60fps sensor requires 300MP/s and can be supported, or a 8MP and 30fps sensor requires 240MP/s and can be supported as well.
3. The total data rate must be smaller than 6Gbps. As mentioned above, if the pixel rate is under 315MP/s and the camera output bit width is less than 16, the total data rate will be under 6Gbps.
4. System analysis needs to be performed for the targeted application to determine if CPU and DDR load will be under the limit.