• The amount of clock cycles between an active command row address strobe (RAS) and a CAS is measured in tRCD. It's the period between the memory controller claiming a row address and the succeeding read or write instruction asserting a column address. Row address to column address delay time is denoted by tRCD.
• The number of clock cycles taken to open a row and access a column is measured in tRCD. tRCD + CL are additional delays introduced by reading the initial bit of memory from a DRAM without any active rows
• tRCD is the time it takes the RAM to get to the new address in the shortest possible time.

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