Artlav
Full Member level 2
Hello.
I'm trying to drive a VGA output (on Altera FPGA dev board) at 640x480@60Hz, but the clock i have is 25Mhz (50+PLL).
I've tried the default timings (in terms of ticks), but monitor says input out of range.
I've been trying to match the times then, increasing horizontal front porch, sync or active area, but it just does not want to work.
The design itself appears to be fine, because if i drive it at 25.2Mhz on another setup, it works nicely.
So, the question is - how does one drives VGA with only 25Mhz clock?
Is it a matter of setting the timings right, or would it take more work?
Default timings i tried - VGA Signal 640 x 480 @ 60 Hz Industry standard timing
I'm trying to drive a VGA output (on Altera FPGA dev board) at 640x480@60Hz, but the clock i have is 25Mhz (50+PLL).
I've tried the default timings (in terms of ticks), but monitor says input out of range.
I've been trying to match the times then, increasing horizontal front porch, sync or active area, but it just does not want to work.
The design itself appears to be fine, because if i drive it at 25.2Mhz on another setup, it works nicely.
So, the question is - how does one drives VGA with only 25Mhz clock?
Is it a matter of setting the timings right, or would it take more work?
Default timings i tried - VGA Signal 640 x 480 @ 60 Hz Industry standard timing