SPRUIE9D May 2017 – May 2024 DRA74P , DRA75P , DRA76P , DRA77P
The clamp value for vertical direction is calculated using the pixel values at the left or right OB region. Line average is calculated for the OB H valid period (2(ISIF_CLVWIN0[2:0] CLVOBH + 1)). The averages for the previous lines are also added back to reduce the difference between the lines, as shown in Figure 9-149.
The position of the first vertical black clamp window is set with the ISIF_CLVWIN2[12:0] CLVSV and ISIF_CLVWIN1[12:0] CLVSH bit fields. The number of vertical windows is set with the ISIF_CLVWIN3[12:0] CLVOBV bit field. ISIF_VDW sets the width of the VD.
The accumulator, which holds the vertical clamp value for the previous line, is reset at the beginning of the OB V valid. The reset value can be selected through the ISIF_CLVWIN0[5:4] CLVRVSL bit field:
The following figures show the OB valid settings and associated vertical clamp value calculation when OB region is at the left (see Figure 9-150) and when OB region is at the right (see Figure 9-151). Each line average value is subtracted from the associated line valid region data.