Semiconductor Memory Data Output Buffering for Timing Margin

The patent divides the data output operation into separate rising edge output and falling edge output operations. The rising output data is output synchronized with the rising edge of the data output strobe signal, while the falling output data is output synchronized with the falling edge. This segmentation allows each data type to be output during its respective valid period, effectively doubling the overall data output speed while maintaining sufficient valid periods for each individual data output.

The patent utilizes periodic clock signals with rising and falling edges to control data output timing. By aligning data output with specific edges of the periodic clock signal and generating the data output strobe signal accordingly, the system maintains regular timing intervals that ensure sufficient valid periods while achieving high-speed periodic data output.

The patent generates the data output strobe signal in advance based on the clock signal before the actual data output occurs. The strobe signal is prepared during the respective clock phase, ensuring that when the data is output, the strobe signal is already positioned to provide an adequate time margin for the memory control apparatus to perform data recovery operations.

The patent separates the strobe signal generation into distinct rising edge strobe and falling edge strobe components, each prepared and output in synchronization with their respective data types. This segmentation ensures that each strobe signal maintains appropriate timing margins for its corresponding data output, preserving data recovery reliability even at high speeds.

The patent employs buffers that serve multiple functions: they latch the output data, buffer the strobe signals, and control the timing of data output. By making these buffers multi-functional, the patent achieves high-speed data output without adding excessive circuit complexity, as the same buffer structures perform multiple critical operations.

The patent combines the data latching function and the strobe signal buffering function into integrated buffer circuits. By merging these functions into unified buffer structures that operate in coordination with the clock signal phases, the patent reduces the overall device complexity compared to having separate dedicated circuits for each function.