Looking at the 74ls157 (datasheet from Ben Eater's website), I noticed that pin 15 is a Strobe input. According to Ben himself, he states in his videos where he uses this IC, that it is a 'master enable for the whole IC'. If that is the case (which it is), why did the manufacturers of the IC decide to use 'Strobe' and not 'Enable'. By definition 'Strobe' means to flash at irregular intervals, which is not what happens with the IC.
\$\begingroup\$
\$\endgroup\$
2
-
1\$\begingroup\$ The only reason I can think of to call that a "Strobe" input is if you need to toggle it Low and High in order for any other pin changes to take effect - ie if you change Select from H->L, Y may not change until you toggle the Strobe pin. However the timing charts on pages 3 and 4 suggest that Y changes whenever Data or Select change, so I don't believe that is that case. It seems to me like a misnamed EN pin, but someone who has used this chip before may know for sure. \$\endgroup\$– InBedded16Commented Nov 11 at 16:18
-
\$\begingroup\$ There are many times the term strobe is used. In this case, when it goes low, the selected input transfers to the output. When it is high the output will not change. A high - > low - > high pulse (a strobe) will transfer the selected input (a or b) to the Y output and hold it until the strobe pulses low again. \$\endgroup\$– Peter SmithCommented Nov 11 at 16:34
Add a comment
|
1 Answer
\$\begingroup\$
\$\endgroup\$
Looking at some other data sheets, pin 15 of LS157 is called enable, not strobe.
As the function is the same, the naming of the pin depends on manufacturer.
