out notice. ISSI assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain
the latest version of this device specification before relying on any published information and before placing orders for products.
Integrated Silicon Solution, Inc. does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can
reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such ap-
plications unless Integrated Silicon Solution, Inc. receives written assurance to its satisfaction, that:
a.) the risk of injury or damage has been minimized;
b.) the user assume all such risks; and
c.) potential liability of Integrated Silicon Solution, Inc is adequately protected under the circumstances
Integrated Silicon Solution, Inc. — www.issi.com
Rev. E
12/01/2011
1
IS42S83200D, IS42S16160D
IS45S83200D, IS45S16160D
DEVICE OVERVIEW
The 256Mb SDRAM is a high speed CMOS, dynamic
random-access memory designed to operate in 3.3V V
dd
and 3.3V V
ddq
memory systems containing 268,435,456
bits. Internally configured as a quad-bank DRAM with a
synchronous interface. Each 67,108,864-bit bank is orga-
nized as 8,192 rows by 512 columns by 16 bits or 8,192
rows by 1,024 columns by 8 bits.
The 256Mb SDRAM includes an AUTO REFRESH MODE,
and a power-saving, power-down mode. All signals are
registered on the positive edge of the clock signal, CLK.
All inputs and outputs are LVTTL compatible.
The 256Mb SDRAM has the ability to synchronously burst
data at a high data rate with automatic column-address
generation, the ability to interleave between internal banks
to hide precharge time and the capability to randomly
change column addresses on each clock cycle during
burst access.
A self-timed row precharge initiated at the end of the burst
sequence is available with the AUTO PRECHARGE function
enabled. Precharge one bank while accessing one of the
other three banks will hide the precharge cycles and provide
seamless, high-speed, random-access operation.
SDRAM read and write accesses are burst oriented starting
at a selected location and continuing for a programmed
number of locations in a programmed sequence. The
registration of an ACTIVE command begins accesses,
followed by a READ or WRITE command. The ACTIVE
command in conjunction with address bits registered are
used to select the bank and row to be accessed (BA0,
BA1 select the bank; A0-A12 select the row). The READ
or WRITE commands in conjunction with address bits
registered are used to select the starting column location
for the burst access.
Programmable READ or WRITE burst lengths consist of
1, 2, 4 and 8 locations or full page, with a burst terminate
option.
FUNCTIONAL BLOCK DIAGRAM (FOR 4M
x
16
x
4
BANKS SHOWN)
CLK
CKE
CS
RAS
CAS
WE
DQML
DQMH
16
2
COMMAND
DECODER
&
CLOCK
GENERATOR
DATA IN
BUFFER
16
MODE
REGISTER
13
REFRESH
CONTROLLER
DQ 0-15
SELF
REFRESH
CONTROLLER
A10
A12
A11
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
BA0
BA1
16
DATA OUT
BUFFER
V
DD
/V
DDQ
V
ss
/V
ss
Q
16
REFRESH
COUNTER
8192
8192
8192
8192
ROW DECODER
MULTIPLEXER
13
MEMORY CELL
ARRAY
13
ROW
ADDRESS
LATCH
13
ROW
ADDRESS
BUFFER
BANK 0
SENSE AMP I/O GATE
COLUMN
ADDRESS LATCH
9
512
(x 16)
BANK CONTROL LOGIC
BURST COUNTER
COLUMN
ADDRESS BUFFER
COLUMN DECODER
9
2
Integrated Silicon Solution, Inc. — www.issi.com
Rev. E
12/01/2011
IS42S83200D, IS42S16160D
IS45S83200D, IS45S16160D
PIN CONFIGURATIONS
54 pin TSOP - Type II for x8
V
DD
DQ0
V
DD
Q
NC
DQ1
V
SS
Q
NC
DQ2
V
DD
Q
NC
DQ3
V
SS
Q
NC
V
DD
NC
WE
CAS
RAS
CS
BA0
BA1
A10
A0
A1
A2
A3
V
DD
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
V
SS
DQ7
V
SS
Q
NC
DQ6
V
DD
Q
NC
DQ5
V
SS
Q
NC
DQ4
V
DD
Q
NC
V
SS
NC
DQM
CLK
CKE
A12
A11
A9
A8
A7
A6
A5
A4
V
SS
PIN DESCRIPTIONS
A0-A12
A0-A9
BA0, BA1
DQ0 to DQ7
CLK
CKE
CS
RAS
CAS
Row Address Input
Column Address Input
Bank Select Address
Data I/O
System Clock Input
Clock Enable
Chip Select
Row Address Strobe Command
Column Address Strobe Command
WE
DQM
V
dd
Vss
V
ddq
Vss
q
NC
Write Enable
Data Input/Output Mask
Power
Ground
Power Supply for I/O Pin
Ground for I/O Pin
No Connection
Integrated Silicon Solution, Inc. — www.issi.com
Rev. E
12/01/2011
3
IS42S83200D, IS42S16160D
IS45S83200D, IS45S16160D
PIN CONFIGURATIONS
54 pin TSOP - Type II for x16
V
DD
DQ0
V
DD
Q
DQ1
DQ2
V
SS
Q
DQ3
DQ4
V
DD
Q
DQ5
DQ6
V
SS
Q
DQ7
V
DD
DQML
WE
CAS
RAS
CS
BA0
BA1
A10
A0
A1
A2
A3
V
DD
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
V
SS
DQ15
V
SS
Q
DQ14
DQ13
V
DD
Q
DQ12
DQ11
V
SS
Q
DQ10
DQ9
V
DD
Q
DQ8
V
SS
NC
DQMH
CLK
CKE
A12
A11
A9
A8
A7
A6
A5
A4
V
SS
PIN DESCRIPTIONS
A0-A12
A0-A8
BA0, BA1
DQ0 to DQ15
CLK
CKE
CS
RAS
CAS
Row Address Input
Column Address Input
Bank Select Address
Data I/O
System Clock Input
Clock Enable
Chip Select
Row Address Strobe Command
Column Address Strobe Command
WE
DQML
DQMH
V
dd
Vss
V
ddq
Vss
q
NC
Write Enable
x16 Lower Byte, Input/Output Mask
x16 Upper Byte, Input/Output Mask
Power
Ground
Power Supply for I/O Pin
Ground for I/O Pin
No Connection
4
Integrated Silicon Solution, Inc. — www.issi.com
Rev. E
12/01/2011
IS42S83200D, IS42S16160D
IS45S83200D, IS45S16160D
PIN CONFIGURATION
54-ball fBGA for x16
(Top View) (8.00 mm x 13.00 mm Body, 0.8 mm Ball Pitch)
