5.2.6.11 Interlaced Frame Content
The LCDC supports progressive and interlaced content. Interlaced video signals provide only half the lines in each frame. Two fields are used alternately, each containing half the lines of the original frame. The top field, with index 0, contains every other line, starting with the first line. The bottom field, with index 1, contains every other line, starting with the second line. This is illustrated in the figure below.
When this mode is selected, the Unified Scaling Engine is used to resample the current frame and interpolate the missing lines. To select Interlaced Content mode, set LCDC_HEOCFG1.ILD to one.
To handle both fields, specific configuration registers are duplicated depending on the field index, as described in the table below.
Field | Progressive | Interlaced Field 0 (Top) | Interlaced Field 1 (Bottom) |
---|---|---|---|
Frame buffer address |
LCDC_HEOYFBA0 LCDC_HEOCBFBA0 LCDC_HEOCRFBA0 |
LCDC_HEOYFBA1 LCDC_HEOCBFBA1 LCDC_HEOCRFBA1 | |
Scaling pixel alignment |
LCDC_HEOCFG28.VXYOFF LCDC_HEOCFG28.VXCOFF LCDC_HEOCFG30.VXSYCFG LCDC_HEOCFG30.VXSCCFG |
LCDC_HEOCFG28.VXYOFF1 LCDC_HEOCFG28.VXCOFF1 LCDC_HEOCFG30.VXSYCFG1 LCDC_HEOCFG30.VXSCCFG1 |