Which statement about the Chip Select (CS) signal in memory systems is true?

Which statement about the Chip Select (CS) signal in memory systems is true?

• A. It enables a specific chip to respond to address requests
• B. It clocks data
• C. It selects the memory bank
• D. It encodes the address

Answer: (A)

Chip Select gates a memory device so it participates in a bus cycle only when the address decoder has matched its assigned range. When the decoded address indicates that a particular chip should respond, its CS line is asserted, allowing that chip to respond to the read or write operation and drive or accept data. All other chips on the same bus have CS deasserted, so their outputs stay inactive and don’t clash on the data lines. Clocks data is not handled by CS; timing for data transfer comes from the clock and data path signals. The CS line isn’t used to encode the address itself; the address lines carry the address, and decoding logic uses that to assert CS for the appropriate chip.

Chip Select gates a memory device so it participates in a bus cycle only when the address decoder has matched its assigned range. When the decoded address indicates that a particular chip should respond, its CS line is asserted, allowing that chip to respond to the read or write operation and drive or accept data. All other chips on the same bus have CS deasserted, so their outputs stay inactive and don’t clash on the data lines.

Clocks data is not handled by CS; timing for data transfer comes from the clock and data path signals. The CS line isn’t used to encode the address itself; the address lines carry the address, and decoding logic uses that to assert CS for the appropriate chip.