Video Interface: Difference between revisions
→Video DAC: Rewrite lede for clarity; don't use "pixel clock" to mean the clock that's 4x as fast as pixels; call out standards-defined frequencies for the video clocks
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(→Video DAC: Rewrite lede for clarity; don't use "pixel clock" to mean the clock that's 4x as fast as pixels; call out standards-defined frequencies for the video clocks) |
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= Video DAC =
The Video DAC
[[File:N64videosys.png|thumb|Video DAC Bus and waveform. Image from: http://members.optusnet.com.au/eviltim/n64rgb/n64rgb.html]]
The Video DAC clock runs at 4 times the speed of the internal pixel clock so the multiplexing can happen on the VI bus. This 4 clock process outputs the RGB colors and the VSync, Hsync, Clamp and Csync and is reset using a dsync reset signal.
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|Low
|}
There are 3 different
File:MX8330 video maths.png|Mx8330 video clock maths and fselect
</gallery>
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!TV Signal Type
!MX8330 Nominal input clock (by definition)
!MX8330 FSEL input
!Measured Video Clock
!Clock Maths using datasheet
|-
|NTSC
|14.32MHz (18 × 227.5 ÷ 286)
|48.62Mhz▼
|HIGH
▲|48.62Mhz
|(14.3 * 17) / 5
|-
|PAL
|17734475 Hz
|49.56Mhz▼
|LOW
▲|49.56Mhz
|(17.
|-
|MPAL
|14.30MHz (18 × 227.25 ÷ 286)
|HIGH
|Not yet measured
|(14.3 * 17) / 5
|}
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