18Mb Σ1x2Lp CMOS I/O
Double Data Rate SigmaRAM™
200 MHz–333 MHz
1.8 V VDD
1.8 V I/O
• Double Data Rate Read and Write mode
• Late Write; Pipelined read operation
• JEDEC-standard SigmaRAM™ pinout and package
• 1.8 V +150/–100 mV core power supply
• 1.8 V CMOS Interface
• ZQ controlled user-selectable output drive strength
• Dual Cycle Deselect
• Burst Read and Write option
• Fully coherent read and write pipelines
• Echo Clock outputs track data output drivers
• 2 user-programmable chip enable inputs
• IEEE 1149.1 JTAG-compliant Serial Boundary Scan
• 209-bump, 14 mm x 22 mm, 1 mm bump pitch BGA package
• Pin-compatible with future 36Mb, 72Mb, and 144Mb
SigmaRAM Family Overview
GS8170DD36 SigmaRAMs are built in compliance with the
SigmaRAM pinout standard for synchronous SRAMs. They
are 18,874,368-bit (18Mb) SRAMs. This family of wide, very
low voltage CMOS I/O SRAMs is designed to operate at the
speeds needed to implement economical high performance
ΣRAMs are offered in a number of configurations including
Late Write, Double Late Write, and Double Data Rate (DDR).
The logical differences between the protocols employed by
these RAMs mainly involve various approaches to write
cueing and data transfer rates. The ΣRAM™ family standard
allows a user to implement the interface protocol best suited to
the task at hand.
Because SigmaRAMs are synchronous devices, address data
inputs and read/write control inputs are captured on the rising
edge of the input clock. Write cycles are internally self-timed
and initiated by the rising edge of the clock input. This feature
eliminates complex off-chip write pulse generation required by
asynchronous SRAMs and simplifies input signal timing. In
DDR mode the device captures Data In on both rising and
falling edges of clock and drives data on both clock edges as
Because the DDR ΣRAM always transfers data in two halves,
A0 is internally set to 0 for the first half of each read or write
transfer, and automatically incremented to 1 for the falling
edge transfer. The address field of a DDR ΣRAM is always
one address pin less than the advertised index depth (e.g., the
512k x 36 has a 512k addressable index).
ΣRAMs support pipelined reads utilizing a rising-edge-
triggered output register. DDR ΣRAMs incorporate rising-
and falling-edge-triggered output registers. They also utilize a
Dual Cycle Deselect (DCD) output deselect protocol.
ΣRAMs are implemented with high performance CMOS
technology and are packaged in a 209-bump BGA.
Key Fast Bin Specs
Rev: 2.03 1/2005
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
© 2002, GSI Technology, Inc.
Datasheet pdf - http://www.DataSheet4U.net/