# Rams and DQ lines

I'm studying DRams and SRams at university and on the slides the lines where a data is read or written is called DQ. But whats does it means? Maybe D is for Data, but Q?

## 2 Answers

I think that the origin of the name comes from the convention for flip flops. On a D flipflop the data in pin is generally called D, and the data out pin, Q. Since the memories data bus is bidirectional, a data pin can be D when it is input or Q when it is output hence the name DQ.

I quote from this IBM article - https://www.ece.cmu.edu/~ece548/localcpy/sramop.pdf

The DQ pins are used for data input and output. DQs on SRAMs come in two forms — on some devices, the inputs and outputs are separate, on others, they are common, with the input and output using the same pin on the memory device. All of IBM Microelectron- ics' SRAM offerings have common I/O.

• Thank you for the reply. I understand what Dq lines do, but I would like to know the meaning of DQ. For example I have a signal called OE where it means "Output Enable" – linofex Jan 22 '17 at 16:30
• Q is the normal designation for an output line for a flip flop, counter etc. D is obviously Data. – JIm Dearden Jan 22 '17 at 16:39
• The origin of the designation, Q, is discussed in this question electronics.stackexchange.com/questions/51625/… – JIm Dearden Jan 22 '17 at 16:45