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On an ALU data sheet there are logic formulae showing the results that will be output for various inputs.

http://www.farnell.com/datasheets/1840939.pdf

(Second from last row on page 3.)

I assume that A+B means bitwise A OR B, this would follow, as the plus in a circle is XOR.

Does AB mean bitwise A AND B?

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  • \$\begingroup\$ It would follow, because the arithmetic plus is indicated by PLUS. And since the multiplication is not among the parts capability (as indicated on the first page), AB would mean bitwise A AND B. \$\endgroup\$
    – Eugene Sh.
    Commented Jun 23, 2016 at 15:48
  • \$\begingroup\$ A lot of sources are already on the google search, no offense I don't think there is a question here. \$\endgroup\$
    – MaMba
    Commented Jun 23, 2016 at 16:16
  • \$\begingroup\$ Unless it is a regex expression your deduction is true. \$\endgroup\$
    – user105652
    Commented Jun 23, 2016 at 22:29

2 Answers 2

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Yes, when written as multiplication in normal math, it means AND in Boolean logic. This does make some sense when you think about it. Make a truth table of multiplying two value that can be either 0 or 1. The result is 0 except when both are 1, then the result is 1. That's exactly what AND does.

This logic doesn't really follow for "+", unless you consider 0 FALSE and anything else TRUE.

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  • \$\begingroup\$ So many words instead just yes \$\endgroup\$
    – user76844
    Commented Jun 23, 2016 at 16:31
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    \$\begingroup\$ A one word answer is pretty much considered useless, and quickly downvoted. Points for the explanation. \$\endgroup\$
    – R Drast
    Commented Jun 23, 2016 at 16:46
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    \$\begingroup\$ unless you consider 0 FALSE and anything else TRUE Like most C-derived programming languages, for example :) \$\endgroup\$
    – cat
    Commented Jun 23, 2016 at 18:25
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You are right AB mean A AND B . It is faster to write AB than A dot B or A AND B

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    \$\begingroup\$ Is it also faster to write "right" than it is to write "write" right? \$\endgroup\$
    – Ben Voigt
    Commented Jun 23, 2016 at 15:51
  • \$\begingroup\$ @BenVoigt Didn't realize the edit, filled the comment box with alternating "right" and "write" to measure typing speed. Only then I noticed the earlier revision. \$\endgroup\$
    – Kroltan
    Commented Jun 24, 2016 at 2:23

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