CY62157EV30

The CY62157EV30 is a high performance CMOS static RAM organized as 512K words by 16 bits. This device features 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 CY62157EV30 also has an automatic power down feature that significantly reduces power consumption when addresses are not toggling. Place the device into standby mode when deselected (CE₁ HIGH or CE₂ LOW or both BHE and BLE are HIGH). The input or output pins (IO₀ through IO₁₅) of CY62157EV30 are placed in a high impedance state when:
• Deselected (CE₁HIGH or CE₂ LOW)
• Outputs are disabled (OE HIGH)
• Both Byte High Enable and Byte Low Enable are disabled (BHE,BLE HIGH)
• Write operation is active (CE₁ LOW, CE₂ HIGH and WE LOW)

To write to the CY62157EV30, take Chip Enable (CE₁ LOW and CE₂ HIGH) and Write Enable (WE) inputs LOW. If Byte Low Enable (BLE) is LOW, then data from IO pins (IO₀ through IO₇) is written into the location specified on the address pins (A0 through A₁₈). If Byte High Enable (BHE) is LOW, then data from IO pins (IO₈ through IO₁₅) is written into the location specified on the address pins (A₀ through A₁₈).

To read from the CY62157EV30, take Chip Enable (CE₁ LOW and CE₂ HIGH) 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 appear on IO₀ to IO₇. If Byte High Enable (BHE) is LOW, then data of CY62157EV30 from memory appears on IO₈ to IO₁₅. See the "Truth Table" on page 10 for a complete description of read and write modes.