The color bar pattern must be programmed in units of a block or word size dependent on the datatype of the video being sent. The sizes are defined in the MIPI CSI-2 specification. For example, RGB888 requires a 3-byte block size which is the same as the pixel size. RAW10 requires a 5-byte block size which is equal to 4 pixels. RAW12 requires a 3-byte block size which is equal to 2 pixels.

When programming the Pattern Generator, software must compute the required bar size in bytes based on the line size and the number of bars. For the standard eight color bar pattern, that would require the following algorithm:

• Select the desired data type, and a valid length for that data type (in pixels).
• Convert pixels/line to blocks/line (by dividing by the number of pixels/block, as defined in the data type specification).
• Divide the blocks/line result by the number of color bars (8), giving blocks/bar
• Round result down to the nearest integer
• Convert blocks/bar to bytes/bar and program that value into the PGEN_BAR_SIZE register

As an alternative, the blocks/line can be computed by converting pixels/line to bytes/line and divide by bytes/block.