working out pixel clock

[Timmeh]

Hi there, Got an exam 2morrow and can't figure it out for the life of me

A CRT monitor is to be used at a pixel resolution of 1034 x 76. The monitor is mutli-sync but it limitation is that its line blanking time must be 10% of the line period and the frame blanking time must be set at 5% of the frame period

Calculate the line period and pixel clock for the graphics system for frame rates of 50Hz non-interlaced and 75Hz interlaced.

If ne1 can do this plz help me step by step would be useful the lecturers notes are a joke to say the least. tried googling and came up with a blank

Thanks

Tim

[desmatic]

Hi there, Got an exam 2morrow and can't figure it out for the life of me

A CRT monitor is to be used at a pixel resolution of 1034 x 76. The monitor is mutli-sync but it limitation is that its line blanking time must be 10% of the line period and the frame blanking time must be set at 5% of the frame period

Calculate the line period and pixel clock for the graphics system for frame rates of 50Hz non-interlaced and 75Hz interlaced.

If ne1 can do this plz help me step by step would be useful the lecturers notes are a joke to say the least. tried googling and came up with a blank

Thanks

Tim

ok here goes,

total number of pixels per line = 1034/(100%-10%) = 1034/.9 = 1148.88 pixels per line.

1034 active pixels
1148.88 pixels per line
114.88 blanking pixels per line

number of lines per refresh =  76/(100%-5%) = 75/.95 =  78.94

75 active lines
78.94 lines total
3.94 blanking lines

pclock = 1148.88 * 78.94 * 50 = 4534629.36Hz

frame = 2 fields if I recall correctly, so 75hz = 37.5Hz per field and the number of lines gets halved to 38.  Blanking is listed by frame (which is kinda weird), so i guess it would be 2.5% per field. Calculations would then follow the same method as the one above.

google gtf.c