GS8640Z18

• NBT (No Bus Turn Around) functionality allows zero wait read-write-read bus utilization; Fully pin-compatible with both pipelined and flow through NtRAM™, NoBL™ and ZBT™ SRAMs
• 2.5 V or 3.3 V +10%/10% core power supply
• 2.5 V or 3.3 V I/O supply
• User-configurable Pipeline and Flow Through mode
• LBO pin for Linear or Interleave Burst mode
• Pin compatible with 4Mb, 9Mb, 18Mb and 36Mb devices
• Byte write operation (9-bit Bytes)
• 3 chip enable signals for easy depth expansion
• ZZ Pin for automatic power-down
• JEDEC-standard 100-lead TQFP package
• RoHS-compliant 100-lead TQFP package available

Note:
Permanent damage to the device may occur if the Absolute Maximum Ratings are exceeded. Operation should be restricted to Recommended Operating Conditions. Exposure to conditions exceeding the Absolute Maximum Ratings, for an extended period of time, may affect reliability of this component.

The GS8640Z18/36T is a 72Mbit Synchronous Static SRAM. GSI's NBT SRAMs, like ZBT, NtRAM, NoBL or other pipelined read/double late write or flow through read/single late write SRAMs, allow utilization of all available bus bandwidth by eliminating the need to insert deselect cycles when the GS8640Z18/36T is switched from read to write cycles.

Because GS8640Z18/36T is a synchronous device, address, data inputs, and read/ write control inputs are captured on the rising edge of the input clock. Burst order control (LBO) must be tied to a power rail for proper operation. Asynchronous inputs of GS8640Z18/36T include the Sleep mode enable (ZZ) and Output Enable. Output Enable can be used to override the synchronous control of the output drivers and turn the RAM's output drivers off at any time. Write cycles are internally self-timed and initiated by the rising edge of the clock input. GS8640Z18/36T feature eliminates complex off-chip write pulse generation required by asynchronous SRAMs and simplifies input signal timing.

The GS8640Z18/36T may be configured by the user to operate in Pipeline or Flow Through mode. Operating as a pipelined synchronous device, meaning that in addition to the rising edge triggered registers that capture input signals, the GS8640Z18/36T incorporates a rising-edge-triggered output register. For read cycles, pipelined SRAM output data is temporarily stored by the edge triggered output register during the access cycle and then released to the output drivers at the next rising edge of clock.

The GS8640Z18/36T is implemented with GSI's high performance CMOS technology and is available in a JEDEC-standard 100-pin TQFP package.