Completely random

Natima · 29 May 2008 at 07:51

but hey....
I was just wondering, seeing as there is Double Data Rate memory....
Hypothetically speaking, is Triple Data Rate or even Quad Data Rate 'actually' possible? I really have no idea how it works but was just wondering if its something we will ever see.

thegoonden · 29 May 2008 at 08:04

Don't know, but what I do know is that it's something to do with being able to perform an operation on both the rising, and falling side of the clock pulse.

if you look at a few clock pulses (square waves I assume, sinusoidal forms are WAY too random for accurate timing uses).............

_-_-_-_-_
(in reality the peak and trough would be the same length obviously, but all I have is - and _ to work with)
SD RAM would get 4 ops in there, on on each peak (or pulse) of the clock wave.

DD RAM, will get 8, one each time the wave transitions from trough to peak, and one as it transitions back to trough.

Using THAT model alone would suggest that DDR is all we'll get.
And even at that, I don't really understand how the above works, is the clock just for timing or is the data modulated onto it, and given that squarewave transitions are notionally instantaneous, how does one apply modulation to the transition rather than one or other "steady" state of the waveform.

Of course, years of studying and lecturing in synthesis have left me a fairly confused individual.

Natima · 29 May 2008 at 08:06

Coincidentally, your years of studying and lecturing in synthesis have left ME a fairly confused individual too!

thegoonden · 29 May 2008 at 08:12

:lol:

I do talk some balls

Think of a second hand on an alarm clock, the sort that moves in jumpy ticks. SD ram can write (or read or do other housekeeping stuff) each time the hand arrives on a new second and stops. DDR can do it as the hand swings into each second, and as it swings out.
(of course for that analogy to work, you have to forget that for the clock hand, moving off the first second and arriving on the second second (oh dear), is in fact the same, single motion, or to visualise each second through blinkers so you only see it alone.....here comes the hand....stop....there goes the hand)

thegoonden · 29 May 2008 at 08:15

Of course, there are better explainations out there, but all those I have found were very heavy on computer tech, and left me with the above as a way of rationalising it. Someone who doesn't see a squarewave timing pulse and instantly think of the harmonic series needed to produce it, may however, come away with a clue

Natima · 29 May 2008 at 18:48

So essentially TDR would only work in the fourth dimension?