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How to get V-Sync and H-Sync signals using 74ACT715-R



Jan 1, 1970
I have trouble in using video sync generator 74ACT715, I want to get
vertical and horizonal sync signal, but I don't know how to control
the input the get the results. Anybody can give me some hints? thanks
a lot.

Dana Raymond, a minor God

Jan 1, 1970
Have you taken a look at the datasheet?
You need to supply a 14.31818MHz clock signal, power supply, and a CLEAR
pulse to get it going. the -R variant should then begin generating signals
based on the default values programmed into its registers.

If you are not getting what you expect (the default settings output blanking
intervals instead of sync signals) then you need to hook up the register
interface signals to a micro of some sort and reprogram the registers to new

What is your specific issue right now? Are you getting signal generation?

Dana Frank Raymond


Jan 1, 1970
Your reply is very helpful, thanks.
Actually,I read the datasheet
( ) lots of times but
couldn't figure my problem out.
I will try your suggestion and I think I can get the default output.
But the default output in Pin 14 an 15 are CSYNC and VGATE, not what I
want (VSYNC and HSYNC). According to the datasheet, I need to change
B2 B1 B0 in REG0 to '0 1 0', the default values are ' 0 0 0', but I
can't find how to control REG0 now, this the big problem. Would you
please give me more suggestions, appreciate it.