Semiconductor Memory Decoder Bank Segmentation

The decoder is segmented into multiple main decoders (first main decoder, second main decoder, etc.) corresponding to different banks. Each main decoder handles decoding for a specific bank, allowing the decoding function to be distributed across multiple smaller circuits rather than requiring one large decoder for all banks. This segmentation enables storage capacity to be increased by adding more banks while each individual decoder circuit maintains a manageable size.

The predecoder is designed as a shared resource that serves multiple banks simultaneously. The same predecoder circuit performs predecoding operations for different banks by receiving bank select signals and internal address signals. This multi-functionality allows the predecoder to support an increased number of banks without requiring proportional increases in predecoder circuit size, thereby improving storage capacity while controlling decoder area.

The decoding function is divided into two stages: predecoding (performed by the shared predecoder) and main decoding (performed by individual main decoders). This segmentation of the decoding process reduces the complexity of each individual decoder circuit while maintaining the ability to address a large number of unit cells per bank. The predecoder handles initial address signal processing, and each main decoder handles bank-specific decoding, distributing the overall complexity across multiple simpler circuits.

The predecoder performs preliminary decoding operations on address signals before they are passed to the main decoders. By pre-processing the address signals and generating intermediate decoded signals, the predecoder reduces the complexity of the subsequent main decoding stage. This preliminary action allows each main decoder to work with already-partially-decoded signals, reducing their circuit complexity while supporting higher integration with more unit cells per bank.

The predecoder functionality is merged into a single shared circuit that serves all banks. Instead of having separate predecoders for each bank, one predecoder is combined to handle predecoding operations for multiple banks by receiving bank select signals and internal address signals. This merging reduces the overall decoder circuit size while maintaining decoding performance through the complementary structure of the shared predecoder and individual main decoders.

The predecoder is designed as a universal circuit that can perform predecoding operations for any bank by receiving bank select signals (STROBE0, STROBE1) and internal address signals. This multi-functional predecoder replaces what would otherwise require multiple separate predecoder circuits, reducing the overall circuit size while maintaining the ability to decode addresses for all banks with the same performance characteristics.