V58C2256404S datasheet(26/61 Pages) MOSEL

Numer części	V58C2256404S

Szczegółowy opis	HIGH PERFORMANCE 2.5 VOLT 256 Mbit DDR SDRAM

PDF	61 Pages

Scroll/Zoom	100%

Producent	MOSEL [Mosel Vitelic, Corp]

Strona internetowa	http://www.moselvitelic.com

Logo

26 / 61 page

V58C2256(804/404/164)S Rev. 1.4 October 2002

MOSEL VITELIC

V58C2256(804/404/164)S

QFC function

when driven low on reads coincident with the start of preamble, this DRAM output signal says that one cy-

cle later there will be the first valid DQS output and returned to HI-Z after this finishing a burst operation. It is

also driven low shortly after a write command is received and returned to HI-Z shortly after the last data strobe

transition is received. Whenever the device is in standby, the signal is HI-Z. DQS is intended to enable an

external data switch. QFC can be enabled or disabled through EMRS control.

QFC timing on Read operation

QFC on reads is enabled coincident with the start of DQS preamble, and disabled coincident with the end

of DQS postamble

Figure 26. QFC timing on read operation

Command

Read

Dout 0

Dout 1

Hi-Z

DQS

DQ’S

QFC

tQPRE

tQPST

CL = 2, BL = 2

V58C2256404S Arkusz danych(PDF) 26 Page - Mosel Vitelic, Corp