help understanding this circuit

[rosestar10]

Hello Please can you help ??? I have a very simple question regarding the nomenclature of general electrical circuits.

When you see pin names next to a component on a schematic does this mean that this location is linked to that pin even if there is no wire.

For example please see the attached file .

If I analyse this circuit it looks to me like resistor block 2 is not really doing anything. Resistor block 1 appears to be acting as a pull up for the address1 pin on the FPGA. Am i correct in assuming this or is resistor block 2 acting as some kind of current limiting resistor as this adds to the total impedance of the line so the current will be limited. It just seems strange that the drawing does not show the line.

Thank you very much for your help.

rosestar10

[pebe]

Strictly speaking, this is not a circuit. It looks similar to a block diagram but it's not of those either.

Block diagrams only indicate the flow of a signal, or the way blocks of circuits are linked. They don't give detail of the connections between components, or supply voltages, as circuits do.

The resistor blocks shown constitute an attenuator that reduces the level of the incoming signal coming from Address1, to a level suitable for FPGA. As such, the Resistor 1 block should be left out and Resistor 2 block should be renamed 'Attenuator'.

The only way a block would normally be shown in a circuit is when it is an IC where the internal components are complex and the block can be treated as a 'black box'. In that case, numbers attached to it are normally the pin numbers of the IC.

Think of it like a block diagram is a flow path that shows the key functions of a circuit at a glance, but a circuit shows all the connections and detail.