DMA Controller PL230 - Why N is multiple for 4 in scatter-gather mode ?

Hi 

In uDMA controller specification (pl230), Table 2-11


It is mention that value of N should be multiple of four. But DMA will perform N+1 tranfer ex. if N=4 dma will perform 5 transfer. 
In scatter-gather mode dma uses primary data structue to configure alternate data structure, and number of transfer for primary should be multiple of four. So here value of N should be 3, 7, 11, 15, etc. and not multiple of four. 

Can anyone please confirm this behaviour ?