zr and ng bits on the ALU output

[Malco]

Hey all,
I bought this book to get rid of some holes in my knowledge. So far I'm enjoying it.

SPOILER ALERT

I went through chapter 1 and most of chapter 2 smoothly, but the discussion never mentions the ZR nor the NG output bits of the ALU.

so, NG is the leftmost bit of OUT, that was easy. What about ZR? should I sum all other bits one by one?

[cadet1620]

Malco wrote

What about ZR? should I sum all other bits one by one?

You made a part in chapter 1 that will tell you if an 8-bit value is non-zero.  Combine the outputs from two of them to compute ZR.

--Mark

[Malco]

Thank you cadet, that was easy