
GS8161Z18(T/D)/GS8161Z32(D)/GS8161Z36(T/D)
Specifications cited are subject to change without notice. For latest documentation see http://www.gsitechnology.com.
Rev:  2.15  11/2004
14/36
 1998, GSI Technology
Burst Cycles
Although NBT RAMs are designed to sustain 100% bus bandwidth by eliminating turnaround cycle when there is transition from 
read to write, multiple back-to-back reads or writes may also be performed. NBT SRAMs provide an on-chip burst address 
generator that can be utilized, if desired, to further simplify burst read or write implementations. The ADV control pin, when 
driven high, commands the SRAM to advance the internal address counter and use the counter generated address to read or write 
the SRAM. The starting address for the first cycle in a burst cycle series is loaded into the SRAM by driving the ADV pin low, into 
Load mode. 
Burst Order
The burst address counter wraps around to its initial state after four addresses (the loaded address and three more) have been 
accessed.   The burst sequence is determined by the state of the Linear Burst Order pin (LBO). When this pin is low, a linear burst 
sequence is selected. When the RAM is installed with the LBO pin tied high, Interleaved burst sequence is selected. See the tables 
below for details.
Mode Pin Functions
Note:
There are pull-up devices on the  FT pin and a pull-down device on the ZZ pin, so those input pins can be unconnected and the chip will operate 
in the default states as specified in the above tables.
Burst Counter Sequences
BPR 1999.05.18
Mode Name
Pin 
Name
State
Function
Burst Order Control
LBO
L
H
Linear Burst
Interleaved Burst
Active
Standby, I
DD
 = I
SB
Power Down Control
ZZ
L or NC
H 
Note: 
The burst counter wraps to initial state on the 5th clock.
Note: 
The burst counter wraps to initial state on the 5th clock.
Linear Burst Sequence
A[1:0] A[1:0] A[1:0] A[1:0]
1st address
00
01
10
11
2nd address
01
10
11
00
3rd address
10
11
00
01
4th address
11
00
01
10
Interleaved Burst Sequence
A[1:0] A[1:0] A[1:0] A[1:0]
1st address
00
01
10
11
2nd address
01
00
11
10
3rd address
10
11
00
01
4th address
11
10
01
00