I am trying to understand how bits are wrote to and read from memory chips. I understand semiconductors, though I don't seem to have a full grip on what a transistor, diode, and capasitors are, and cannot relate how the three work together to make up a memory cell. I can't seem to complete this story by myself, and so, like always, turn to the heroic cboard team!
The following is what I have compiled through a bit of reading and some imagination. Please, correct me on anything, and add to!
A memory cell has three pins: input, select, and output. In order for the cell to retain a voltage, recognizable by its ouput pin, both the select and input pins have to be supplied with a similar voltage at exactly the same time. Once either of the voltages leaves, or leaves as a whole, the cell loses its voltage, and the cell now supplies no voltage to the output pin: a binary 0.
Here, I cannot go further. These are my problems: since there are thousands of memory cells in a chip, how can each one have a 'pin'. my solution is that, each chip has wires running vertically and horizontally through them (the input and select pins respectivally?), and when they meet, turn 'on' a cell. These are the metal 'legs' that appear on the chip. Am i wrong here? Which brings me to another problem. Nowadays, there are billions of cells in a single chip. if the above explination was true, could there be THAT many vert. and hor. wires running through the chips? Is there another explination, because the most 'legs' i see on one of my chips is around 32, on any one side.
Secondly, the above was how they chips got written to. How are the actually READ, in relationship with the output pin?
Thirdly, and a follow up to the second quetion just above, many chips have wire 'legs' on all their 4 sides. why the extra 2? does current run through the first 2 (select and input) and out the other 2? are the other two the output? How is that actually READ?
On the other hand, some chips only have a pair of 'legs,' along 2 opposite sides. How does this work?
Lengthy, but hopefully someone will find it enjoyable to help. Thank you.