k7i161884b Samsung Semiconductor, Inc., k7i161884b Datasheet - Page 7

• Manufacturer Part Number: k7i161884b
• Description: 512kx36-bit, 1mx18-bit Ddrii Cio B4 Sram
• Manufacturer: Samsung Semiconductor, Inc.

K7I161884B
K7I163684B
WRITE OPERATIONS
PROGRAMMABLE IMPEDANCE OUTPUT BUFFER OPERATION
K7I163684B and K7I161884B can be operated with the single clock pair K and K,
To operate these devices in single clock mode, C and C must be tied high during power up and must be maintained high
After power up, this device can′t change to or from single clock mode.
System flight time and clock skew could not be compensated in this mode.
Write cycles are initiated by activating R/W as low at the rising edge of the positive input clock K.
Address is presented and stored in the write address register synchronized with next K clock.
For 4-bit burst DDR operation, it will write two 36-bit, 18-bit or 8-bit data words with each write command.
The first “late writed” data is transferred and registered in to the device synchronous with next K clock rising edge.
Next burst data is transferred and registered synchronous with following K clock rising edge.
Continuous write operations are initiated with K rising edge.
And “late writed” data is presented to the device on every rising edge of both K and K clocks.
When the LD is disabled, the K7I163684B and K7I161884B will enter into deselect mode.
The device disregards input data presented on the same cycle W disabled.
The K7I163684B and K7I161884B support byte write operations.
With activating BW
In K7I161884B BW
And in K7I163684B BW
The designer can program the SRAM's output buffer impedance by terminating the ZQ pin to V
The value of RQ (within 15%) is five times the output impedance desired.
For example, 250
Impedance updates occur early in cycles that do not activate the outputs, such as deselect cycles.
In all cases impedance updates are transparent to the user and do not produce access time "push-outs" or other anomalous behav-
ior in the SRAM.
There are no power up requirements for the SRAM. However, to guarantee optimum output driver impedance after power up, the
SRAM needs 1024 non-read cycles.
K7I163684B and K7I161884B utilize internal DLL (Delay-Locked Loops) for maximum output data valid window.
It can be placed into a stopped-clock state to minimize power with a modest restart time of 1024 clock cycles.
Circuitry automatically resets the DLL when absence of input clock is detected.
SINGLE CLOCK MODE
CLOCK CONSIDERATION
DEPTH EXPANSION
Each port can be selected and deselected independently with R/W be shared among all SRAMs and provide a new LD signal
Before chip deselected, all read and write pending operations are completed.
for each bank.
instead of C or C for output clocks.
during operation.
Ω
0
0
resistor will give an output impedance of 50
or BW
controls write operation to D0:D8, BW
2
controls write operation to D18:D26, BW
1
(BW
2
or BW
3)
in write cycle, only one byte of input data is presented.
1
512Kx36 & 1Mx18 DDRII CIO b4 SRAM
controls write operation to D9:D17.
Ω
- 7 -
.
3
controls write operation to D27:D35.
SS
through a precision resistor(RQ).
Rev. 5.0 July 2006