DDR-II SRAM 2-Word Burst Architecture Specification Sheet

CY7C1516AV18, CY7C1527AV18

CY7C1518AV18, CY7C1520AV18

Document Number: 001-06982 Rev. *D Page 7 of 30

CQ Output Clock CQ Referenced with Respect to C. This is a free running clock and is synchronized to the input clock

for output data (C) of the DDR-II. In the single clock mode, CQ is generated with respect to K. The timing

for the echo clocks is shown in the AC Timing table.

Output Clock CQ Referenced with Respect to C. This is a free running clock and is synchronized to the input clock

for output data (C

) of the DDR-II. In the single clock mode, CQ is generated with respect to K. The timing

for the echo clocks is shown in the AC Timing table.

ZQ Input Output Impedance Matching Input. This input is used to tune the device outputs to the system data bus

impedance. CQ, CQ, and Q

[x:0]

output impedance are set to 0.2 x RQ, where RQ is a resistor connected

between ZQ and ground. Alternatively, this pin can be connected directly to V

DDQ

, which enables the

minimum impedance mode. This pin cannot be connected directly to GND or left unconnected.

DOFF

Input DLL Turn Off − Active LOW. Connecting this pin to ground turns off the DLL inside the device. The timing

in the DLL turned off operation differs from those listed in this data sheet. For normal operation, this pin

can be connected to a pull up through a 10 KΩ or less pull up resistor. The device behaves in DDR-I

mode when the DLL is turned off. In this mode, the device can be operated at a frequency of up to 167

MHz with DDR-I timing.

TDO Output TDO for JTAG.

TCK Input TCK Pin for JTAG.

TDI Input TDI Pin for JTAG.

TMS Input TMS Pin for JTAG.

NC N/A Not Connected to the Die. Can be tied to any voltage level.

NC/144M Input Not Connected to the Die. Can be tied to any voltage level.

NC/288M Input Not Connected to the Die. Can be tied to any voltage level.

REF

Input-

Reference

Reference Voltage Input. Static input used to set the reference level for HSTL inputs, outputs, and AC

measurement points.

Power Supply Power supply Inputs to the Core of the Device.

Ground Ground for the device.

DDQ

Power Supply Power Supply Inputs for the Outputs of the Device.

Pin Definitions (continued)

Pin Name IO Pin Description

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