DRAM operations are done with using of single capacitor and transistor and their operations are totally depended on the charging stored on the capacitor.
DRAM invented by Robert Dennard in 1966, at IBM.
Working of DRAM
Dynamic Random Access Memory (DRAM) uses two elements as a storage cell like as transistor and capacitor. To keep charge or discharge of capacitors to be using the transistor.
If logic high or “1” it means capacitor has fully charging otherwise it gets discharge then its logic low or “0”. All operations of charging or discharging are performing by work line and bit line. Show in figure
DRAM Operations Are
There are two functions of DRAM; like as
- Write operation
- Reading Operation
Write Operation
In this operation, Voltage is going to supply on bit line as well as signal gets supply on the address line for closing the transistor.
Reading Operation
While storing the information on the cell, then transistor get turning on and voltage supplies for bit line. Due to this process, some charge stores in the capacitors. After some time transistor get turning off mode, and it goes to discharge. Hence, entire information stores in the cell which can read easily.
Also Read: Advantages, Disadvantages, Applications, Uses of DRAM
There are various lines which are using in the Read and Write Operations; such as –
- /CAS, the Column Address Strobe: This line helps to choose the column to be addressing. Address inputs get obtaining on the falling edge of/CAS. It gets to enable a column that chosen from the open row for getting read or write operations.
- /OE, Output Enable: The /OE gets to use, if controlling several memory chips in parallel form. It helps to handle the output to data I/O pins. If /RAS and /CAS get to low, /WE is high, and /OE is also getting low, then data pins driven by DRAM chip.
- /RAS, the Row Address Strobe: The /RAS line selects the row to be address. Address inputs get obtain on the falling edges of the /RAS line. The row is getting to open as long as /RAS remains low.
- /WE, Write Enable: The signal monitors that falling edge of /CAS is read or writes. High enables a read action but low enables the write action. Data inputs also captured on the falling edge of /CAS.
How to Organize DRAM?
Today’s, Dynamic RAM is available in different types of forms but it depends upon their applications; for example – DIMM (Dual Inline Memory Module) consists several onboard DRAM chips.
These types of DIMMs have 1 GB memory, but you can see “2Rx8” written on the sticker. 2R represents that this module comes in rank 2, but x8 mean and that output width of data coming from every DRAM chips.
Also Read: Difference Between SRAM and DRAM | SRAM Vs DRAM
A rank is a individual addressable group of DRAMs. In this scenario, one rank is group of four DRAM chips, but we have 2 ranks if there are 8 total.
DIMM has higher level of organization with getting of DRAM’s rank. Mention in the figure that, every chip organizes into number of memory arrays and banks, and columns. Show in the image, DRAM chip has four banks.
Each bank works individually to the others, it means all operations such as reading, writing, and pre-recharging can perform on bank without stressing to other.
