英飞凌小封装芯片 CY62157EV30LL-45ZXIT

　　Functional Description

　　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 device 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 (I/O0 through I/O15) are placed in a high impedance state when the device is deselected (CE1HIGH or CE2 LOW), the outputs are disabled (OE HIGH), Byte High Enable and Byte Low Enable are disabled (BHE, BLE HIGH), or a write operation is active (CE1 LOW, CE2 HIGH and WE LOW).

　　To write to the device, take Chip Enable (CE1 LOW and CE2 HIGH) 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 A18). 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 A18).

　　To read from the device, 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 I/O0 to I/O7. If Byte High Enable (BHE) is LOW, then data from memory appears on I/O8 to I/O15. See Truth Table on page 13 for a complete description of read and write modes.