Arria 10 DSP 18×18 Sum of 2 Mode

[Altera_Forum]

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

[Altera_Forum]

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]

Thanks for the clarification. 

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