Video Interface: Difference between revisions

{{#invoke:Register table|definitions

| 31-17 | Undefined | Initialized to <code>0</code>

| 10 | Undefined | Initialized to <code>0</code>

| 5 | VBUS_CLOCK_ENABLE | Vbus Clock Enable <br>1 {{=}} Enabled <br>0 {{=}} Disabled <br>{{spaces|4}}'''''Warning: Always leave disabled!''' Setting this bit enables a second driver, which will output on the same pin as another driver, possibly causing physical console damage.''

| 4 | DIVOT_ENABLE | Fixes minor artifacts left over from anti-aliasing (more details below) <br>1 {{=}} Enabled (usually used if AA is enabled) <br>0 {{=}} Disabled

}}

'''Extra Details:'''

: '''DIVOT_ENABLE'''

:: When enabled, this feature fixes artifacts that the anti-aliasing algorithm leaves behind. The median color of three neighboring pixels, from any pixels on or next to silhouette edges, is selected to be displayed in place of the center pixel. Effectively removing any one pixel divots that can be seen in some fractal-based terrains. The anti-aliasing function encounters issues when multiple fragments occur on a single pixel. Since this filter is only used on edges, and not the surface of an object, texture details will not be affected. Be aware that bad quality effects can occur when the ''decal line'' rendering mode is used in conjunction with this filter, as the rendering mode generates edges that the filter can detect.

| 23-0 | ORIGIN[23:0] | RDRAM base address of the video output Frame Buffer. This can be changed as needed to implement double or triple buffering.

}}

==== <span style="display:none;">0x0440 0008 - VI_WIDTH ====

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| 11-0 | WIDTH[11:0] | This is the width in pixels of the frame buffer if you draw to the frame buffer based on a different width than what is given here the image will drift with each line to the left or right. The common values are 320 and 640, the maximum value is 4095. The same value would also be used on drawing commands for clipping or scissors. This can also be used with High Res interlacing modes to change the odd and even lines of the frame buffer to be drawn to screen by doubling the width of this value and changing the VI_ORIGIN register to the odd or even field being displayed.

}}

==== <span style="display:none;">0x0440 000C - VI_V_INTR ====

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| 31-30 | Undefined | Initialized to <code>0</code>

| 29-20 | BURST_START[9:0] | Start of color burst in pixels from hsync

| 15-8 | BURST_WIDTH[7:0] | Color burst width in pixels

| 7-0 | HSYNC_WIDTH[7:0] | Horizontal sync width in pixels<br>Default value of <code>0x01</code>

:* horizontal sync width in pixels: 57 (decimal)

:* color burst width in pixels: 34 (decimal)

:* start of color burst in pixels from h-sync: 62 (decimal)

: PAL @ any resolution is <code>0x0404233A</code>

:* horizontal sync width in pixels: 58 (decimal)

:* color burst width in pixels: 35 (decimal)

:* start of color burst in pixels from h-sync: 64 (decimal)

==== <span style="display:none;">0x0440 0018 - VI_V_SYNC ====

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{{#invoke:Register table|definitions

| 31-10 | Undefined | Initialized to <code>0</code>

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==== <span style="display:none;">0x0440 001C - VI_H_SYNC ====

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| 20-16 | LEAP[4:0] | 5-bit leap pattern used only for PAL. Should always use standard value of <code>0x15</code>

| 15-12 | Undefined | Initialized to <code>0</code>

}}

==== <span style="display:none;">0x0440 0020 - VI_H_SYNC_LEAP ====

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{{#invoke:Register table|definitions

| 31-28 | Undefined | Initialized to <code>0</code>

| 15-12 | Undefined | Initialized to <code>0</code>

}}

 

==== <span style="display:none;">0x0440 0024 - VI_H_VIDEO ====

{{#invoke:Register table|definitions

| 31-26 | Undefined | Initialized to <code>0</code>

| 15-10 | Undefined | Initialized to <code>0</code>

}}

==== <span style="display:none;">0x0440 0028 - VI_V_VIDEO ====

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| 11-0 | X_SCALE[11:0] | 1/horizontal scale up factor (2.10 format)

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==== <span style="display:none;">0x0440 0034 - VI_Y_SCALE ====

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| 11-0 | Y_SCALE[11:0] | 1/vertical scale up factor (2.10 format)

}}

==== <span style="display:none;">0x0440 0038 - VI_TEST_ADDR ====

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{{#invoke:Register table|definitions

| 31-7 | Undefined | Initialized to <code>0</code>

}}

==== <span style="display:none;">0x0440 003C - VI_STAGED_DATA ====

{{#invoke:Register table|foot}}

{{#invoke:Register table|definitions

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Unlike floating-point numbers, fixed-point numbers allocate a specific number of bits for the integer (X) and

In this format, a certain number of bits are dedicated to the integer part, while the

the 2.10 format, where two bits are used for the integer part and ten bits are

allocated for the fractional part, resulting in a total of twelve bits.

</math>

 

=== Interlace Mode ===

The NTSC (and PAL) standard support interlace mode which is commonly associated with high resolution, but it can be used for more than that.