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LAB Carry-In/Out

Altera_Forum
Honored Contributor II
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Hi! 

 

I havte to make a ripple carry adder for a Cyclon II FPGA, the adder module is working properly but not using the LEs carry chain connections (LAB Carry-In, LAB Carry-Out). My question is that how can i made the Quartus II to use the internal carry chain? (if it is possible) 

 

Auto Carry Chains set to On and Ignore Carry Buffers set to Off at the settings menu. 

 

The LPM_ADDER module use that chain, mines why not? 

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Altera_Forum
Honored Contributor II
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Finally i made it :) Using the carry_sum primitive between the full adders forces the compiler to use the internal carry chain. 

 

Later i could post an example if someone is interested.
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Altera_Forum
Honored Contributor II
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--- Quote Start ---  

Finally i made it :) Using the carry_sum primitive between the full adders forces the compiler to use the internal carry chain. 

 

Later i could post an example if someone is interested. 

--- Quote End ---  

 

Hi, 

I'm working on a project that need to use the internal carry chain between two full adders. Could you please post your example here. Thanks so much.
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