Samsung M391B5773DH0, M391B5273DH0 Input/Output Functional Description, Symbol Type Function

Unbuffered DIMM

datasheet

Rev. 1.0

DDR3L SDRAM

7. Input/Output Functional Description

Symbol

Type

Function

CK and

are differential clock inputs. All the DDR3 SDRAM addr/cntl inputs are sampled on the crossing of positive

CK0-CK1

CK

SSTL

edge of CK and negative edge of CK. Output (read) data is reference to the crossing of CK and CK (Both directions of

CK0-CK1

crossing)

CKE0-CKE1

SSTL

Activates the SDRAM CK signal when high and deactivates the CK signal when low. By deactivating the clocks, CKE low

initiates the Power Down mode, or the Self-Refresh mode

Enables the associated SDRAM command decoder when low and disables the command decoder when high. When the

S0-S1

SSTL

command decoder is disabled, new command are ignored but previous operations continue. This signal provides for

external rank selection on systems with multiple ranks.

SSTL

and

(ALONG WITH

RAS,

CAS,

WE

RAS,

CAS,

WE

S) define the command being entered.

When high, termination resistance is enabled for all DQ, DQS,

and DM pins, assuming the function is enabled in the

ODT0-ODT1

SSTL

DQS

Extended Mode Register Set (EMRS).

VREFDQ

Supply

Reference voltage for SSTL 15 I/O inputs.

VREFCA

Supply

Reference voltage for SSTL 15 command/address inputs.

VDDQ

Supply

Power supply for the DDR3 SDRAM output buffers to provide improved noise immunity. For all current DDR3 unbuffered

DIMM designs, VDDQ shares the same power plane as VDD pins.

BA0-BA2

SSTL

Selects which SDRAM bank of eight is activated.

During a Bank Activate command cycle, Address input defines the row address (RA0-RA13)

During a Read or Write command cycle, Address input defines the column address, In addition to the column address,

AP is used to invoke autoprecharge operation at the end of the burst read or write cycle. If AP is high, autoprecharge is

A0-A14

SSTL

selected and BA0, BA1, BA2 defines the bank to be precharged. If AP is low, autoprecharge is disabled. During a pre-

charge command cycle, AP is used in conjunction with BA0, BA1, BA2 to control which bank(s) to precharge. If AP is

high, all banks will be precharged regardless of the state of BA0, BA1 or BA2. If AP is low, BA0, BA1 and BA2 are used

is sampled during READ and WRITE commands to determine if burst chop

to define which bank to precharge. A12(BC)

(on-the-fly) will be performed (HIGH, no burst chop; Low, burst chopped).

DQ0-DQ63

SSTL

Data and Check Bit Input/Output pins.

CB0-CB7

DM is an input mask signal for write data. Input data is masked when DM is sampled High coincident with that input data

DM0-DM81

SSTL

during a write access. DM is sampled on both edges of DQS. Although DM pins are input only, the DM loading matches

the DQ and DQS loading.

VDD,VSS

Supply

Power and ground for DDR3 SDRAM input buffers, and core logic. VDD and VDDQ pins are tied to VDD/VDDQ planes on

these modules.

DQS0-DQS81

SSTL

Data strobe for input and output data.

-

1

DQS0

DQS8

SA0-SA2

-

These signals and tied at the system planar to either VSS or VDDSPD to configure the serial SPD EERPOM address

range.

SDA

-

This bidirectional pin is used to transfer data into or out of the SPD EEPROM. An external resistor may be connected

from the SDA bus line to VDDSPD to act as a pull-up on the system board.

SCL

-

This signal is used to clock data into and out of the SPD EEPROM. An external resistor may be connected from the SCL

bus time to VDDSPD to act as a pull-up on the system board.

VDDSPD

Supply

Power supply for SPD EEPROM. This supply is separate from the VDD/VDDQ power plane. EEPROM supply is operable

from 3.0V to 3.6V.

-

The

pin is connected to the

pin on each DRAM. When low, all DRAMs are set to a know state.

RESET

RESET

RESET

This signal indicates that a thermal event has been detected in the thermal sensing device. The system should guarantee

EVENT

Output

the electrical level requirement is met for the EVENT pin on TS/SPD part

NOTE :

1. DM8, DQS8 and DQS8 are for ECC UDIMM only.

- 7 -