45 ns access time — what it means for bus timing
The 45 ns access time is the time from address valid to data valid on the bus. The write cycle time is also 45 ns, so read and write cycles are symmetric.
512K x 8 organization — byte-wide bus constraint
The 512K x 8 organization means this SRAM presents an 8-bit data bus. It is a direct fit for 8-bit microcontrollers.
Lifecycle and sourcing posture
The RMLV0408EGSA-4S2#KA1 carries an Active lifecycle status with ROHS3 compliance. There is no announced end-of-life or last-time-buy window, so it remains a viable choice for new production builds. For dual-sourcing considerations, the evidence does not list an official second-source alternate, so qualification of a backup supplier would require independent evaluation.