Polarity of operands is a sort of arbitrary thing, a matter of data interpretation. What the different symbols mean is that if the data are treated as "active LOW", then the propagate signals also must be treated as "active LOW", and vice versa.

I'm experimenting with the 74LS181 ALU (see here if you like), and it is going well, but I am unable to figure out how to use the A=B, A>B, and A<B comparator functions. The datasheet states, "The comparator output (A=B) of the device goes HIGH when all four function outputs (not F0 to not F3) are HIGH and can be used to indicate logic ...

Aug 19, 2017 · When trying to add two numbers on my two cascaded 74LS181's I find that the result seems to be right when I tie the carry (Cn) of the least significant one to Vcc, contra my expectation that Cn should be low. Trying to add zero and zero yields b'00000001'... I did tie the Cn+4 of the LSB to the Cn of the MSB. Any thoughts? Gerard

Jun 22, 2017 · I'm trying to make a homebrew CPU but having problems with the 74LS181 ALU, which I'm simulating in Logisim software before diving into real ICs and breadboards. I've cascaded two 74181 following instructions found in many sites such as this. This works fine with most of addings I tried, but some don't work. For example:

Set up your circuit in Multisim with the 74LS181 IC, connecting the 4-bit inputs to channels A and B using mini-dip switches. Answer:- 1) schematic the output when M=H and s0s1s2s3= 0000, the output is A'.

Question: 1) Simulate a 4 bits ALU using 74LS181 IC. Connecting 4 bits to the channel A and 4 bits to the channel B controlling the data input with mini-dip switches. The output verification must be done using LED's or indicators. vce X14 2.5 vec HE ma X102 Test the following sequences of operations using any numbers in A and B. Table 1 ...

Choose one · 1 point SN54/74LS181 L A+B L L L г г г FUNCTION TABLE MODE SELECT ACTIVE LOW INPUTS INPUTS & OUTPUTS LOGIC ARITHMETIC** S3 S2 S1 So (M = H) (MEL) (n =L) L L L A A minus 1 L L L H AB AB minus 1 L L H A+B AB minus 1 L H H Logical 1 minus 1 H L A+B A plus (A + B) L H L H B AB plus (A + B) L H H A® В A minus B minus 1 L H H H …

Question: 1) Simulate a 4 bits ALU using 74LS181 IC. Connecting 4 bits to the channel A and 4 bits to the channel B controlling the data input with mini-dip switches. The output verification must be done using LED's or indicators. 2.5V VCC 5.OVT X16 X15 X14 2.5V VOC 2.5V SVT 15 SS STEIN VCC S.OV 12 X11 X102.5V 15 25 15 Test the following ...

SN54/74LS181 JIJI A+B II 7 FUNCTION TABLE MODE SELECT ACTIVE LOW INPUTS INPUTS & OUTPUTS LOGIC ARITHMETIC** S3 S2 S1 So (M = H) ( MEL) (Cn-L) L L A A minus 1 L H AB AB minus 1 H A+B AB minus 1 L H H Logical 1 minus 1 L L L A+B A plus (A+BL L L H B AB plus (A + B) L H L AOB A minus B minus 1 L H H A+B H L AB A plus (A+B) H H AOB Aplus B H H …

The 74LS181 is an ALU chip with the following function table. Input A, input B, and output F are 4-bits each. Write VHDL code to implement the logic functions of the chip. Use a ease statement. Write VHDL code to implement the arithmetic functions of the chip. Use a case statement.