MEMORY MODULES AND PINS CONFIGURATIONS

MEMORY


DIMM -- DUAL INLINE MEM MODULE
I. 64 BIT
II.  2 CUT 168 PINS BLACK COLOR >> USE FOR SDRAM 133 MHZ
III. SINGLE CUT 184 PINS >> USE FOR DDR1
     SINGLE CUT 240 PINS >> USE FOR DDR2


SIMM -- SINGLE INLINE MEM MODULE

I. 30 PINS WITHOUT CUT 8 BIT >> USE FOR 65MHZ SDRAM
II. 72 PINS SINGLE CUT 32 BIT >> USE FOR 85 MHZ , 100 MHZ SDRAM


RIMM -- RAMBUS INLINE MEM MODULE

I.  16 BIT 184 PINS TWO CUT
II. 32 BIT 232 PINS SINGLE CUT

NOTE:- 1. FOUR RIMM SLOTS ARE PROVIDED FOR 16 BIT MODULES WHILE TWO SLOTS ARE PROVIDED FOR
32 BITS MODULES IN MOTHERBOARDS.THESE SOLOTS ARE TO BE FILLED IN PAIRS.

2. UNIQUE WITH RIMM IS THAT THE MOTHERBOARD MUST HAVE OCCUPIED EVERY RIMM SLOT.IF A SINGLE
RIMM SLOT IS REMAINED VACANT THE SYSTEM WILL NOT BOOT.



FOR PORTABLE PC


SODIMM -- SMALL OUTLINE DIMM

32 BIT AND 64 BIT >> 144 PIN


MicroDIMM

32 BIT 64 BIT >> 144 PINS AND 172 PINS

DIRECT MEMORY ACCESS

IN a computer the CPU, Memory and DMA controller are the central units to which other
peripheral subsystems like input/output controllers are interfaced.

The type of information(signals) flow between the cpu and the memory are the following:-

1.Data signals :> This includes instruction and data .

2.Address signals :> This is memory address or peripheral address.

3.Control signals :> This includes signals like memory write, memory read,I/O write,I/O read interrupt , reset.



For each type of signal or communication there is one path or bus ;-

1. Data Bus :> The data bus is used when any unit is sending data,instruction or command
code to some other unit.

2. Address Bus :> The address bus is used when one unit is sending address information to
another unit.

3. Control Bus :> The control bus is used when one unit is sending a control signal to
another unit.


Bus Arbitration :> Usually , the cpu is the bus master in a computer.It decides who should
access or control the bus when more than one unit wants the bus at the
same time.This is known as Bus Arbitration.

An unit who needs the bus makes a request to the CPU and awaits sanction.Till the CPU issue
sanction the requesting unit does not attempt to use the bus.In a PC apart from the CPU
only the DMA controller controls the bus.