2
PIN NAMES
DEVICE OPERATION
The UT67164 has four control inputs called Enable 1 (E1), 
Enable 2 (E2), Write Enable (W), and Output Enable (G); 13 
address inputs, A(12:0); and eight bidirectional data lines, 
DQ(7:0). E1 and E2 are device enable inputs that control device 
selection, active, and standby modes. Asserting both E1 and E2 
enables the device, causes I
DD
to rise to its active value, and 
decodes the 13 address inputs to select one of 8,192 words in 
the memory. W controls read and write operations. During a 
read cycle, G must be asserted to enable the outputs.
Table 1. Device Operation Truth Table
Notes: 
1. “X” is defined as a “don’t care” condition. 
2. Device active; outputs disabled. 
READ CYCLE
A combination of W greater than V
IH 
(min), E1 less than V
IL 
(max), and E2 greater than V
IH 
(min) defines a read cycle. Read 
access time is measured from the latter of device enable, Output 
Enable, or valid address to valid data output.
Read Cycle 1, the Address Access read in figure 3a, is initiated 
by a change in address inputs while the chip is enabled with G 
asserted and W deasserted. Valid data appears on data outputs 
DQ(7:0) after the specified t
AVQV
 is satisfied. Outputs remain 
active throughout the entire cycle. As long as device enable and 
output enable are active, the address inputs may change at a rate 
equal to the minimum read cycle time (t
AVAV
).
Figure 3b shows Read Cycle 2, the Chip Enable-controlled 
Access. For this cycle, G remains asserted, W remains 
deasserted, and the addresses remain stable for the entire cycle. 
After the specified t
ETQV
 is satisfied, the eight-bit word 
addressed by A(12:0) is accessed and appears at the data outputs 
DQ(7:0).
Figure 3c shows Read Cycle 3, the Output Enable-controlled 
Access. For this cycle, E1 and E2 are asserted, W is deasserted, 
and the addresses are stable before G is enabled. Read access 
time is t
GLQV
 unless t
AVQV
 or t
ETQV
 have not been satisfied.
A(12:0) Address W Write
DQ(7:0) Data Input/Output G Output Enable
E1 Enable 1 V
DD
Power
E2
1
Enable 2 V
SS
Ground
1 28 
2 27 
3 26 
4 25 
5 24 
6 23 
7 22 
8 21 
9 20 
10 19 
11 18 
12 17 
13 16 
14 15
Figure 2. SRAM Pinout 
NC
A12
A7 
A6 
A5 
A4 
A3 
A2 
A1
A0 
DQ0 
DQ1 
DQ2
Vss
VDD 
W
E2 
A8 
A9 
A11 
G 
A10 
E1 
DQ7 
DQ6 
DQ5 
DQ4 
DQ3
G W E1
E2
I/O Mode Mode
X1 
X X 0 3-state Standby
X X 1 X 3-state Standby 
X 0 0 1 Data in Write
1 1 0 1 3-state
Read
2
0 1 0 1 Data out Read