GS842Z18CB/GS842Z36CB
4Mb Pipelined and Flow Through
Synchronous NBT SRAMs
250 MHz–100 MHz
3.3 V VDD
2.5 V and 3.3 V VDDQ
119-Bump BGA
Commercial Temp
Industrial Temp
Rev: 1.01 8/2011
1/29
2011, GSI Technology
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
Features
256K x 18 and 128K x 36 configurations
User configurable Pipeline and Flow Through mode
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
Pin-compatible with 2Mb, 9Mb, and 18Mb devices
3.3 V +10%/–10% core power supply
2.5 V or 3.3 V I/O supply
LBO pin for Linear or Interleave Burst mode
Byte write operation (9-bit Bytes)
3 chip enable signals for easy depth expansion
Clock Control, registered address, data, and control
ZZ Pin for automatic power-down
JEDEC-standard 119-bump BGA package
RoHS-compliant package available
Functional Description
The GS842Z18/36CB is a 4Mbit 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 device is switched from read to write cycles.
Because it 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 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. This feature eliminates complex off-
chip write pulse generation required by asynchronous SRAMs
and simplifies input signal timing.
The GS842Z18/36CB may be configured by the user to operate
in Pipeline or Flow Through mode. Operating as a pipelined
synchronous device, in addition to the rising-edge-triggered
registers that capture input signals, the device 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 GS842Z18/36CB is implemented with GSI's high
performance CMOS technology and is available in a JEDEC-
standard 119-bump BGA package.
Parameter Synopsis
–250
–200
–166
–150
–100
Pipeline
3-1-1-1
tCycle
tKQ
IDD
4.0 ns
2.5 ns
TBD
5.5 ns
3.0 ns
TBD
6.0 ns
3.5 ns
TBD
6.7 ns
3.8 ns
TBD
10 ns
4.5 ns
TBD
Flow
Through
2-1-1-1
tKQ
tCycle
IDD
5.5 ns
TBD
6.5 ns
TBD
7.0 ns
TBD
7.5 ns
TBD
12 ns
TBD