Another zr post

[a1ph4byte]

The solution seems fairly straightforward to me IF I were able to sub bus the OUT pin or IF I were able to sub bus internal pins. Since these two functions are not allowed, is there an elegant solution to this using only built-in chips? I understand that I could build a custom chip to break out a sub-bus or extend an existing chip to do the same, but my goal was to only use what was provided.  

Thanks in advance for the feedback.

[a1ph4byte]

Another case of RTFM.

The answer is yes zr can be determined with built-in chips. And can be found in the fine details of the HDL survival guide. Specifically having a better understanding of sub-buses...


"This implementation causes an error on the Or8Way statement. This needs to be coded as:
       Something16 (in=in, out[4..11]=notIn);
       Or8Way (in=notIn, out=out);"
                                        --HDL Survival Guide

[WBahn]

You got it!

The way sub-bussing is done in this HDL is pretty klunky. Hopefully they incorporated key aspects of the HDL Survival Guide into the 2nd Ed.