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Altera_Forum's avatar
Altera_Forum
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15 years ago

Asynchronous data

hi agin, I whant to clock in data at the rate of 48MHz (Camera). At the falling edge of the PIX_CLK data is valid. My design will work at 48MHz but the both clk's wont be synchronised...
Altera_Forum's avatar
Altera_Forum
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15 years ago

The problem is mostly if your two clocks aren't at the same exact frequency. If they come from the same oscillator, but are shifted, then you won't miss any data. But if there is a slight frequency difference, then from time to time either one word won't get read in time (it will fill the fifo with one additional word), or the read side will attempt to read the fifo but no data will be available. If you have a 100ppm difference this will happen approximately every 0.2ms so it's not negligible.

Edit: oups, didn't see you didn't have a continuous stream... then as long as you use the fifo's full and empty signals to control the flow, you should be ok