Apparatus for generating data strobe signal applicable to double data rate SDRAM

A synchronous memory device having an apparatus for generating a data strobe signal, the apparatus for generating the data strobe signal comprising:

• a preamble control means for controlling a preamble state of the data strobe signal in response to a data strobe preamble control signal;
• a plurality of pairs of pull-up/pull-down signal generating drivers coupled to the preamble control means, each pair of pull-up/pull-down drivers having a first pull-up/pull-down driver for receiving a first pipe counter signal to generate the pull-up and pull-down signals, and a second pull-up/pull-down driver for receiving a second pipe counter signal to output the pull-down signal and the pull-up signal, each driver having a first input terminal, a second input terminal and a third input terminal;
• a common pull-up signal buffering means for buffering the pull-up signal to generate a buffered pull-up signal, wherein the buffered pull-up signal is commonly inputted to said second input terminal of each driver, said common pull-up signal buffering means coupled to receive from each driver one of the pull-up signal and the pull-down signal output from each driver;
• a common pull-down signal buffering means for buffering the pull-down signal to generate a buffered pull-down signal, wherein the buffered pull-down signal is commonly inputted to said third input terminal of each driver, said common pull-down signal buffering means coupled to receive from each driver one of the pull-up signal and the pull-down signal output from each driver;
• and
• a data strobe signal driving means for outputting the data strobe signal in response to the pull-up signals, the pull-down signals and a data strobe enable signal.

A synchronous memory device having an apparatus for generating a data strobe signal, the apparatus for generating the data strobe signal comprising:

• a preamble control means for controlling a preamble state of the data strobe signal in response to a data strobe preamble control signal;
• a signal generating portion including a plurality of pairs of pull-up/pull-down signal generating drivers coupled to the preamble control means, a first pair of pull-up/pull-down drivers having a first pull-up/pull-down driver for receiving a first pipe counter signal to generate the pull-up and pull-down signals, and a second pull-up/pull-down driver for receiving a second pipe counter signal to output the pull-down signal and the pull-up signal, a second pair of pull-up/pull-down drivers having a third pull-up/pull-down driver for receiving a third pipe counter signal to generate the pull-up and pull-down signals, and a fourth pull-up/pull-down driver for receiving a fourth pipe counter signal to output the pull-down signal and the pull-up signal, and a third pair of pull-up/pull-down drivers having a fifth pull-up/pull-down driver for receiving a fifth pipe counter signal to generate the pull-up and pull-down signals, and a sixth pull-up/pull-down driver for receiving a sixth pipe counter signal to output the pull-down signal and the pull-up signal, each driver having a first input terminal, a second input terminal and a third input terminal;
• a common pull-up signal buffering means for buffering the pull-up signal to generate a buffered pull-up signal, wherein the buffered pull-up signal is commonly inputted to said second input terminal of each driver, said common pull-up signal buffering means coupled to receive from each driver one of the pull-up signal and the pull-down signal output from each driver;
• a common pull-down signal buffering means for buffering the pull-down signal to generate a buffered pull-down signal, wherein the buffered pull-down signal is commonly inputted to said third input terminal of each driver, said common pull-down signal buffering means coupled to receive from each driver one of the pull-up signal and the pull-down signal output from each driver;
• and
• a data strobe signal driving means for outputting the data strobe signal in response to the pull-up signals, the pull-down signals and a data strobe enable signal.