15 ns access time — timing margin for zero-wait-state operation
For a 50 MHz bus with a 20 ns cycle, the 15 ns access leaves a 5 ns margin for PCB trace delay and clock skew — enough for a clean layout on a two-layer board but tight if long traces or multiple loads are on the bus.
256K x 16 organization — address and data bus width
With a 256K x 16 organization, this part presents an 18-bit address bus and a 16-bit data bus. That 16-bit width matches processors with a 16-bit external data bus directly; for 8-bit or 32-bit controllers, two devices can be paired for 32-bit width or byte-lane control is handled by the upper address bits. The 4 Mbit density provides 512 KB of storage, enough for boot code shadowing, packet buffers, or display frame storage in mid-complexity embedded systems.
No level translation is needed on the address or data lines when interfacing to a 3.3 V FPGA, ASIC, or MCU memory controller.
44-SOJ package — footprint and assembly
The 44-SOJ package uses J-leads on a 0.400-inch (10.16 mm) wide body, with a standard 1.27 mm pitch. It is a surface-mount package that reflows with conventional solder profiles. The SOJ footprint is well-established in memory modules and embedded boards; the J-lead form factor provides good coplanarity and visual solder-joint inspection.