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Arria 10 DSP 18×18 Sum of 2 Mode

Altera_Forum
Honored Contributor II
887 Views

I am looking at the  

Intel® Arria® 10 Native Fixed PointDSP IP Core User Guide 

ug-01163 

2017.03.13 https://www.altera.com/content/dam/altera-www/global/en_us/pdfs/literature/ug/ug_nfp_dsp.pdf 

 

 

 

 

 

On page 14, it indicates the equation for the 18x18 Sum of 2 mode is  

resulta =[±(ax * ay) + (bx * by)] 

 

Looking at the block diagram in Figure 3, I think it should be: 

resulta =[±(ax * (ay ± az)) ± (bx * (by ± bz))] 

 

Is that correct, or is there an error in the block diagram? 

 

Also, what is the significance of white blocks or dotted blocks in the block diagram? 

 

 

 

 

For instance, does the negate function exist in this mode (it is white)? 

 

Thanks
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2 Replies
Altera_Forum
Honored Contributor II
150 Views

Hi, 

 

Equation in user guide is when preadder is disabled. 

If you enable preadder out equation will be [±(ax * (ay ± az)) ± (bx * (by ± bz))]. 

 

Best Regards, 

Anand Raj Shankar 

(This message was posted on behalf of Intel Corporation)
Altera_Forum
Honored Contributor II
150 Views

Thanks for the clarification. 

 

Also, what is the significance of white blocks or dotted blocks in the block diagram?
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