# Why do we need 'R_out' in 2-BUS arch?

Given some abstract architecture of CPU:

Note that this CPU has 2-BUS. Why do we need the R_out and R_in? If I use Gra/Grb/Grc then obviousely I will need R_out. The Same for R_in when I use Sra/Srb/Src?

Sorry if the question is not qualified enough. Thanks in advenced.

• @JDoe Did that answer the question? – laptop2d May 17 at 14:57
• @laptop2d I commented in your answer. – J. Doe May 20 at 13:15