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Altera_Forum
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15 years ago

Using the ALTLVDS_RX DDR in = DDR out?

Hi, Can anyone tell me that by using ALTLVDS_RX core provided by Altera, and if i use deserialization factor of 6; if the input in DDR format, the output of this block will be in DDR format too...
Altera_Forum's avatar
Altera_Forum
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15 years ago

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Only when the serialization factor is 2 the DDR registers are used and SERDES is not used.

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Not quite right. Software SERDES (Cyclone series) uses DDR registers for all deserialization factors, hardware SERDES (Stratix, Arria) doesn't use it at all.

The original question isn't still clear to me. Normally you would supply a frame (slow) clock rather than a bit (fast) clock to a SERDES block, the fast clock is generated internally. So the difference between SDR and DDR is just an internal detail of the SERDES, which you don't have to care for.