A428316 Series
Preliminary
256K X 16 CMOS DYNAMIC RAM WITH EDO PAGE MODE
PRELIMINARY (August, 2002, Version 0.3)
1
AMIC Technology, Inc.
Features
n
Organization: 262,144 words X 16 bits
n
Part Identification
- A428316 (512 Ref.)
n
Single 5.0V power supply/built-in VBB generator
n
Low power consumption
- Operating: 110mA (-25 max)
-
Standby: 2.5mA (TTL), 1.0mA (CMOS)
1.0mA (Self-refresh current)
n
High speed
- 25/35 ns RAS access time
- 12/17 ns column address access time
-
8/10 ns CAS access time
-
12/16 ns EDO Page Mode Cycle Time
n
Industrial operating temperature range: -40
C to 85
C
for -U
n
Fast Page Mode with Extended Data Out
n
Separate CAS (
UCAS
,
LCAS
) for byte selection
n
512 Refresh Cycle in 8ms
n
Read-modify-write, RAS -only, CAS -before- RAS ,
Hidden refresh capability
n
TTL-compatible, three-state I/O
n
JEDEC standard packages
-
400mil, 40-pin SOJ
-
400mil, 40/44 TSOP type II package
General Description
The A428316 is a new generation randomly accessed
memory for graphics, organized in a 262,144-word by 16-
bit configuration. This product can execute Byte Write
and Byte Read operation via two CAS pins.
The A428316 offers an accelerated Fast Page Mode
Pin Configuration
n
n
SOJ
n
n
TSOP
VCC
I/O
0
I/O
1
NC
A1
A2
A3
VCC
A4
A5
A6
A7
A8
I/O
13
I/O
14
I/O
15
VSS
A428316S
21
WE
RAS
I/O
12
OE
I/O
2
I/O
3
I/O
4
I/O
5
I/O
6
I/O
7
A0
NC
NC
VCC
VSS
UCAS
LCAS
NC
I/O
8
I/O
9
I/O
10
I/O
11
VSS
20
19
18
12
16
17
13
14
15
11
10
9
8
7
6
5
4
3
2
1
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
VCC
I/O
0
I/O
1
NC
A1
A2
A3
A4
A5
A6
A7
A8
I/O
13
I/O
14
I/O
15
VSS
A428316V
23
WE
RAS
I/O
12
I/O
2
I/O
3
I/O
4
I/O
5
I/O
6
I/O
7
A0
NC
NC
VCC
VSS
UCAS
LCAS
NC
I/O
8
I/O
9
I/O
10
I/O
11
VSS
22
21
20
14
18
19
15
16
17
13
10
9
8
7
6
5
4
3
2
1
24
25
26
27
28
29
30
31
32
35
36
37
38
39
40
41
42
43
44
VCC
OE
cycle with a feature called Extended Data Out (EDO).
This allow random access of up to 512 words within a row
at a 83/62 MHz EDO cycle, making the A428316 ideally
suited for graphics, digital signal processing and high
performance computing systems.
Pin Descriptions
Symbol
Description
A0 A8
Address Inputs
I/O
0
- I/O
15
Data Input/Output
RAS
Row Address Strobe
LCAS
Column Address Strobe for Lower Byte
(I/O
0
I/O
7
)
UCAS
Column Address Strobe for Upper Byte
(I/O
8
I/O
15
)
WE
Write Enable
OE
Output Enable
VCC
5.0V Power Supply
VSS
Ground
NC
No Connection
A428316 Series
PRELIMINARY
(August, 2002, Version 0.3)
2
AMIC Technology, Inc.
Selection Guide
Symbol
Description
-25
-35
Unit
t
RAC
Maximum RAS Access Time
25
35
ns
t
AA
Maximum Column Address Access Time
12
17
ns
t
CAC
Maximum CAS Access Time
8
10
ns
t
OEA
Maximum Output Enable ( OE ) Access Time
8
10
ns
t
RC
Minimum Read or Write Cycle Time
44
62
ns
t
PC
Minimum EDO Cycle Time
12
16
ns
Functional Description
The A428316 reads and writes data by multiplexing an 18-
bit address into a 9-bit row and 9-bit column address.
RAS and CAS are used to strobe the row address and the
column address, respectively.
The A428316 has two CAS inputs:
LCAS
controls I/O
0
-
I/O
7
, and
UCAS
controls I/O
8
-
I/O
15
,
UCAS
and
LCAS
function in an identical manner to CAS in that either will
generate an internal CAS signal. The CAS function and
timing are determined by the first CAS (
UCAS
or
LCAS
) to transition low and by the last to transition high.
Byte Read and Byte Write are controlled by using
LCAS
and
UCAS
separately.
A Read cycle is performed by holding the WE signal high
during RAS / CAS operation. A Write cycle is executed by
holding the WE signal low during RAS / CAS operation;
the input data is latched by the falling edge of WE or
CAS , whichever occurs later. The data inputs and outputs
are routed through 16 common I/O pins, with RAS , CAS ,
WE and OE controlling the in direction.
EDO Page Mode operation all 512 columns within a
selected row to be randomly accessed at a high data rate.
A EDO Page Mode cycle is initiated with a row address
latched by RAS followed by a column address latched by
CAS . While holding RAS low, CAS can be toggled to
strobe changing column addresses, thus achieving shorter
cycle times.
The A428316 offers an accelerated Fast Page Mode cycle
through a feature called Extended Data Out, which keeps
the output drivers on during the CAS precharge time (t
cp
).
Since data can be output after CAS goes high, the user is
not required to wait for valid data to appear before starting
the next access cycle. Data-out will remain valid as long as
RAS and OE are low, and WE is high; this is the only
characteristic which differentiates Extended Data Out
operation from a standard Read or Fast Page Read.
A memory cycle is terminated by returning both RAS and
CAS high. Memory cell data will retain its correct state by
maintaining power and accessing all 512 combinations of
the 9-bit row addresses, regardless of sequence, at least
once every 8ms through any RAS cycle (Read, Write) or
RAS Refresh cycle ( RAS -only, CBR, or Hidden). The CBR
Refresh cycle automatically controls the row addresses by
invoking the refresh counter and controller.
Power-On
The initial application of the VCC supply requires a 200 s
wait followed by a minimum of any eight initialization cycles
containing a RAS clock. During Power-On, the VCC
current is dependent on the input levels of RAS and CAS .
It is recommended that RAS and CAS track with VCC or
be held at a valid V
IH
during Power-On to avoid current
surges.
A428316 Series
PRELIMINARY
(August, 2002, Version 0.3)
4
AMIC Technology, Inc.
Truth Table
Function
RAS
UCAS
LCAS
WE
OE
Address
I/Os
Notes
Standby
H
H
H
X
X
X
High-Z
Read: Word
L
L
L
H
L
Row/Col.
Data Out
Read: Lower Byte
L
H
L
H
L
Row/Col.
I/O
0-7
= Data Out
I/O
8-15
= High-Z
Read: Upper Byte
L
L
H
H
L
Row/Col.
I/O
0-7
= High-Z
I/O
8-15
= Data Out
Write: Word
L
L
L
L
H
Row/Col.
Data In
Write: Lower Byte
L
H
L
L
H
Row/Col.
I/O
0-7
= Data In
I/O
8-15
= X
Write: Upper Byte
L
L
H
L
H
Row/Col.
I/O
0-7
= X
I/O
8-15
= Data In
Read-Write
L
L
L
H
L
L
H
Row/Col.
Data Out
Data In
1,2
EDO-Page-Mode Read: Hi-Z
-First cycle
-Subsequent Cycles
L
L
H
L
H
L
H
L
H
L
H
H
H
L
H
L
Row/Col.
Col.
Data Out
Data Out
2
2
EDO-Page-Mode Write
-First cycle
-Subsequent Cycles
L
L
H
L
H
L
H
L
H
L
L
L
H
H
Row/Col.
Col.
Data In
Data In
1
1
EDO-Page-Mode Read-Write
-First cycle
-Subsequent Cycles
L
L
H
L
H
L
H
L
H
L
H
L
H
L
L
H
L
H
Row/Col.
Col.
Data Out
Data In
Data Out
Data In
1, 2
1, 2
Hidden Refresh Read
L
H
L
L
L
H
L
Row/Col.
Data Out
2
Hidden Refresh Write
L
H
L
L
L
L
X
Row/Col.
Data In
High-Z
1
RAS -Only Refresh
L
H
H
X
X
Row
High-Z
CBR Refresh
H
L
L
L
X
X
X
High-Z
3
Self Refresh
H
L
L
L
H
X
X
High-Z
Note: 1. Byte Write may be executed with either
UCAS
or
LCAS
active.
2. Byte Read may be executed with either
UCAS
or
LCAS
active.
3. Only one
CAS
signal (
UCAS
or
LCAS
) must be active.
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