DDR SDRAM
Double data rate synchronous dynamic random-access memory (DDR SDRAM) is a class of memory integrated circuits used in computers. DDR SDRAM, also called DDR1 SDRAM, has been superseded by DDR2 SDRAM, DDR3 SDRAM and DDR4 SDRAM. None of its successors are forward or backward compatible with DDR1 SDRAM, meaning DDR2, DDR3, and DDR4 memory modules will not work in DDR1-equipped motherboards, and vice versa.
Compared to single data rate (SDR) SDRAM, the DDR SDRAM interface makes higher transfer rates possible by more strict control of the timing of the electrical data and clock signals. Implementations often have to use schemes such as phase-locked loops and self-calibration to reach the required timing accuracy. The interface uses double pumping (transferring data on both the rising and falling edges of the clock signal) to double data bus bandwidth without a corresponding increase in clock frequency. One advantage of keeping the clock frequency down is that it reduces the signal integrity requirements on the circuit board connecting the memory to the controller. The name "double data rate" refers to the fact that a DDR SDRAM with a certain clock frequency achieves nearly twice the bandwidth of a SDR SDRAM running at the same clock frequency, due to this double pumping.
Podcasts:
-
by Ani Difranco
Back Back Back
by: Ani DifrancoBack, back, back in the back of your mind
Are you learning an angry language?
Tell me boy, boy, boy are you tending to your joy
Or are you just letting it vanquish?
Back, back, back in the dark of your mind
Where the eyes of your demons are gleaming
Are you mad, mad, mad about the life you never had
Even when you are dreaming
Who are these old, old, old people in these nursing homes
Scowling away at nothing like big rag dolls
Just cursing at the walls and pulling out all of their stuffing
Every day is a door leading back to the core
Yes, old age will distill you
And if you're this, this, this full of bitterness now
Some day it will just fill you
When you sit right down in the middle of yourself
You're gonna wanna have a comfortable chair
So renovate your soul before you get too old
'Cuz you're gonna be housebound there
When you're old, you fold up like an envelope
And you mail yourself right inside
And there's nowhere to go except out real slow
Are you ready boy for that ride?
Your arrogance is gaining on you and so is eternity
You better practice happiness, you better practice humility
You took the air, you took the time
You were fed and you were free
Now you'd better put some beauty back
While you got the energy
You'd better put some beauty back, boy