In random-access memory timing, the time from the start of a read cycle until valid data is available (ending at tACS or tAA) is called what?

Introduction / Context:
Memory data sheets define several timing parameters to ensure reliable reads and writes. For reads, designers care about how long after a read begins until the data outputs are valid. This is encapsulated in the access time, often specified as tAA (address access time) and tACS (chip select access time).

Given Data / Assumptions:

• We are examining read timing only.
• tAA and tACS are common parameters for asynchronous SRAM/ROM and historic DRAM specs.
• Read cycle start is defined by address/chip select assertion, depending on device.

Concept / Approach:
Access time is the interval from the point a read is initiated to when the memory device outputs valid data within specified voltage thresholds. Whether measured from address valid (tAA) or from chip select asserted (tACS), the endpoint is the arrival of valid, stable data.

Step-by-Step Solution:
Identify the read initiation event (address stable and CS asserted).Trace the device timing until data lines settle into valid logic levels.That interval is reported as tAA or tACS; both are forms of access time.Therefore, the time described is access time.

Verification / Alternative check:
Compare with typical SRAM datasheets: timing diagrams label tAA/tACS as access-time metrics culminating in data valid windows.

Why Other Options Are Wrong:
Data hold time: describes how long data must remain valid after a control edge, not time-to-valid.Read cycle time: full duration from one read to the next; larger than access time.Write enable time: pertains to writes, not reads.Setup time: requirement before a clock/control event, not data-out delay.

Common Pitfalls:
Confusing the start reference for access time and mixing up hold/setup with access. Always check the diagram legends in the datasheet.

Final Answer:
Access time