Patent · US Expired

Double data rate synchronous dynamic random access memory semiconductor device

US7038972B2 · kind B2 · utility

9Cited by
3References
20Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMar 4, 2004
Grant dateMay 2, 2006
Priority date
Expiry dateSep 27, 2024

Classification

  • Technology area (CPC G)Physics
  • CPC primaryG11C7/222
  • WIPO fieldComputer technology
  • WIPO sectorElectrical engineering

Abstract

A double data rate (“DDR”) synchronous dynamic random access memory (“SDRAM”) semiconductor device is provided that prevents a conflict between data read from and data written to the DDR SDRAM semiconductor device when data is written to the DDR SDRAM semiconductor device, which includes a delay locked loop (“DLL”) circuit, a clock signal control unit, an output unit, and an output control unit, where the DLL circuit compensates for skew of an input clock signal and generates an output clock signal; the clock signal control unit receives a read signal activated when data stored in the DDR SDRAM semiconductor device is read out, a DLL locking signal activated when the DLL circuit performs a locking operation on the input clock signal, and the output clock signal, and outputs the output clock signal when either the read signal or the DLL locking signal is active; the output unit buffers data stored in the DDR SDRAM semiconductor device and outputs the data to outside of the DDR SDRAM semiconductor device in synchronization with the output clock signal output from the clock signal control unit; and the output control unit receives the output clock signal output from the clock signal c…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.