EDJ2104BASE datasheet(89/148 Pages) ELPIDA

89 / 148 page

EDJ2104BASE, EDJ2108BASE

Preliminary Data Sheet E1505E20 (Ver. 2.0)

TDQS, /TDQS function (MR1)

TDQS (Termination Data Strobe) is a feature of

×8 DDR3 SDRAM that provides additional termination resistance

outputs that may be useful in some system configurations.

TDQS is not supported in

×4 configurations. When enabled via the mode register, the same termination resistance

function is applied to the TDQS and /TDQS pins that are applied to the DQS and /DQS pins.

In contrast to the RDQS function of DDR2 SDRAM, TDQS provides the termination resistance function only. The

data strobe function of RDQS is not provided by TDQS.

The TDQS and DM functions share the same pin. When the TDQS function is enabled via the mode register, the DM

function is not supported. When the TDQS function is disabled, the DM function is provided and the /TDQS pin is

not used. See Table TDQS, /TDQS function for details.

The TDQS function is available in

×8 DDR3 SDRAM only and must be disabled via the mode register A11 = 0 in

MR1 for

×4 configurations.

[TDQS, /TDQS function]

A11@MR1

TDQS enable

Disable

Enable

Notes: 1. If TDQS is enabled, the DM function is disabled.

2. When not used, TDQS function can be disabled to save termination power.

3. TDQS function is only available for

×8 DRAM and must be disabled for ×4.

[Function matrix]

A11@MR1 (TDQS enable)

DM/TDQS

NU/ /TDQS

High-Z

TDQS

/TDQS

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