March 2002
AS7C33256NTD16A
AS7C33256NTD18A
®
TM
ꢀꢁꢀꢂꢃꢄꢅꢆꢇ&ꢈꢆꢉꢈꢊꢃꢋꢌꢍꢎꢃꢏꢐꢑꢒꢃꢓꢔꢕ
Features
• Economical 100-pin TQFP package
• Byte write enables
• Organization: 262,144 words × 16 or 18 bits
• NTD architecture for efficient bus operation
™1
• Clock enable for operation hold
• Multiple chip enables for easy expansion
• 3.3V core power supply
• 2.5V or 3.3V I/O operation with separate V
• 30 mW typical standby power
• Self-timed write cycles
• Fast clock speeds to 200 MHz in LVTTL/LVCMOS
• Fast clock to data access: 3.0/3.1/3.5/4.0/5.0 ns
• Fast OE access time: 3.0/3.1/3.5/4.0/5.0 ns
• Fully synchronous operation
• “Flow-through” or “pipelined” mode
• Asynchronous output enable control
DDQ
• Interleaved or linear burst modes
• Snooze mode for standby operation
™
1 NTD is a trademark of Alliance Semiconductor Corporation.
Pin arrangement for TQFP (top view)
Logic block diagram
18
18
Q
D
A[17:0]
Address
register
Burst logic
CLK
A17
NC
NC
D
Q
1
80
79
78
77
76
75
74
73
72
71
70
69
68
67
66
65
64
63
62
61
60
59
58
57
56
55
54
53
52
51
NC
NC
CE0
CE1
CE2
2
Write delay
3
NC
addr. registers
18
V
V
4
DDQ
DDQ
SSQ
CLK
V
V
5
SSQ
NC
NC
R/
W
6
NC
7
BWa
DQPa, NC
DQa
CLK
Control
logic
8
DQb
DQb
BWb
ADV / LD
FT
9
DQa
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
V
V
V
DQa
DQa
SSQ
SSQ
DDQ
256K x 16/18
V
DDQ
DQb
DQB
FT
SRAM
Array
TQFP 14x20mm
LBO
ZZ
CLK
V
SS
V
NC
DD
V
NC
16/18
16/18
DD
DQ [a:b]
Q
D
Data
Input
Register
V
DQb
DQb
ZZ
SS
DQa
DQa
V
16/18 16/18
CLK
V
DDQ
DDQ
SSQ
V
V
SSQ
DQb
DQb
DQa
DQa
NC
16/18
DQPb,
NC
NC
NC
CLK
CEN
V
CLK
SSQ
DDQ
NC
V
V
SSQ
DDQ
V
Output
Register
NC
NC
NC
OE
NC
NC
16/18
OE
DQ [a:b]
Note: Pins 24, 74 are NC for ×16
Selection Guide
-200
5.0
-183
5.4
-166
6
-133
7.5
133
4
-100
10
Units
ns
Minimum cycle time
166
3.5
475
130
30
100
5
Maximum pipelined clock frequency
Maximum pipelined clock access time
Maximum operating current
200
3.0
183
3.1
MHz
ns
425
100
30
325
90
570
160
30
540
140
30
mA
mA
mA
Maximum standby current
30
Maximum CMOS standby current (DC)
3/8/02; v.1.6
Alliance Semiconductor
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