8-way Or gate

[ikanhear]

in the book it uses this as the chip API box

chip name: Or8way
Inputs: in[8]
Outputs: out
Function;=: out=or(in[0],in[1],...,in[7]).

Now to me this looks wrong, this looks as if it is describing a 1 way or gate with 8 bits. I thought it should look like;

inputs: a,b,c,d,e,f,g,h
Outputs: out

Can anyone point out why it is in[8] instead of a,b,c,d,e,f,g,h ?

thanks

[cadet1620]

When you use the Or8Way later in the projects, it will be much more convenient to connect its inputs if they are a bus rather than individual named inputs.

When you are learning about binary numbers on buses in project 2, think about what Or8Way means for an 8-bit binary number.

--Mark

[ikanhear]

ahhh so there is no way of knowing whether

inputs: in[8]
Outputs : out

is a 1way8bit or gate (1 way or gate wouldnt make sense but just for example) or a 8way1bit or gate.

you have to look at the function to know which is which?

[cadet1620]

A "1-way 8-bit" gate would need to have out[8] so that each of the 1-way gates would have an output.

In the hardware world, you often see one-input Nand and Nor gates used in place of Nots. This reflects that electrically the gates are almost identical. This is a schematic diagram for a TTL 3-input Nand gate:

The only difference between this gate and a 2-input Nand and a Not is the number of emitters in transistor Q1 on the left. Remove the B and C inputs and the emitters connected to them and you get a Not.

--Mark

[ikanhear]

i understand now, thank you for being so clear and the speedy reply!