HP HP-Bench-Briefs-1976-01-04 free download

File name HP-Bench-Briefs-1976-01-04.pdf

I i* * d SQ * 4 c#\* $$\Gb SERVICE INFORMATION FROM HEWLETT-PACKARD JANUARY-APRIL, 1976 * 0% % i? \&% LOGIC SYMBOLS logic. Thoge wbo interpret the circk as bv TO^ rmpmr State Devbs). This first Internal and external in- h subsequent articles showing how these indicators are combined to kmrr memningful and use- ful &jic $ymbJS. physical value, the l s po&W level es The primary purpose of the new being the Low state. A polarity i n d i i o r standard is hopefully another step to- symbol at an input indicatesthat a low ward eliminating the confusion be- input is required. A polarity indiitor tween positive/negative logic levels, symbol at an output indicates that the and resolving the controversy be- output i tow. High inputs and high s twmn"p0larity" thinkers and "stab'' at9 Shawn w w u t the polerity ttdnkers. Toward t i end, the hs r symbol. The polarity indicator aryl allows two generai types symbol on the output of the NAND symbols; rectangular (IEC) and dis- gate shown in Figure 3 can be cor- tinctive shaped. Then, for clarity, qual- Note tne use of H (hih) and L (low) in rectly interpreted only one way: the ifiers are placed inside and outside the the truth tables. Keep in mind that the output will be low when the two inputs logic symbols that describe the exact device is going to respond to Highs are high. The polarity indicator symbol function of the circuit, the polarity that (more positive level) and Lows (least on the output of the NOR gate shown is required at the input, and the polar- positive) and the operation of the cir- in Figure 4 will be low when e