The CY62137CV25/30/33 and CY62137CV are high-performance CMOS static RAMs organized as 128K words by 16 bits. These devices feature advanced circuit design to provide ultra-low active current. This is ideal for providing More Battery Life™ (MoBL^®) in portable applications such as cellular telephones. The devices also has an automatic power-down feature that significantly reduces power consumption by 80% when addresses are not toggling. The device can also be put into standby mode reducing power consumption by more than 99% when deselected (/CE HIGH or both /BLE and /BHE are HIGH). The input/output pins (I/O₀ through I/O₁₅) are placed in a high-impedance state when: deselected (/CE HIGH), outputs are disabled (/OE HIGH), both Byte High Enable and Byte Low Enable are disabled (/BHE, /BLE HIGH), or during a write operation (/CE LOW, and /WE LOW).

Writing to the device is accomplished by taking Chip Enable (/CE) and Write Enable (/WE) inputs LOW. If Byte Low Enable (/BLE) is LOW, then data from I/O pins (I/O₀ through I/O₇), is written into the location specified on the address pins (A₀ through A₁₆). If Byte High Enable (/BHE) is LOW, then data from I/O pins (I/O₈ through I/O₁₅) is written into the location specified on the address pins (A₀ through A₁₆).

Reading from the device is accomplished by taking Chip Enable (/CE) and Output Enable (/OE) LOW while forcing the Write Enable (/WE) HIGH. If Byte Low Enable (/BLE) is LOW, then data from the memory location specified by the address pins will appear on I/O₀ to I/O₇. If Byte High Enable (/BHE) is LOW, then data from memory will appear on I/O₈ to I/O₁₅. See the truth table at the back of this data sheet for a complete description of read and write modes.