64Mb: x4, x8, x16
SDRAM
SYNCHRONOUS
DRAM
MT48LC16M4A2 – 4 Meg x 4 x 4 banks
MT48LC8M8A2 – 2 Meg x 8 x 4 banks
MT48LC4M16A2 – 1 Meg x 16 x 4 banks
For the latest data sheet, please refer to the Micron Web
site: www.micron.com/dramds
FEATURES
PIN ASSIGNMENT (Top View)
• PC66-, PC100-, and PC133-compliant
• Fully synchronous; all signals registered on
positive edge of system clock
• Internal pipelined operation; column address can
be changed every clock cycle
• Internal banks for hiding row access/precharge
• Programmable burst lengths: 1, 2, 4, 8, or full page
• Auto Precharge, includes CONCURRENT AUTO
PRECHARGE, and Auto Refresh Modes
• Self Refresh Modes: standard and low power
• 64ms, 4,096-cycle refresh
• LVTTL-compatible inputs and outputs
• Single +3.3V ±0.3V power supply
54-Pin TSOP
x4 x8 x16
NC
NC
DQ0
NC
NC
NC
DQ1
NC
NC
OPTIONS
-
MARKING
• Configurations
16 Meg x 4 (4 Meg x 4 x 4 banks)
8 Meg x 8 (2 Meg x 8 x 4 banks)
4 Meg x 16 (1 Meg x 16 x 4 banks)
16M4
8M8
4M16
• WRITE Recovery (tWR)
t
WR = “2 CLK”1
A2
• Plastic Package – OCPL2
54-pin TSOP II (400 mil)
54-pin TSOP II (400 mil) Lead-free
TG
P
• Timing (Cycle Time)
10ns @ CL = 2 (PC100)
7.5ns @ CL = 3 (PC133)
7.5ns @ CL = 2 (PC133)
6ns @ CL = 3 (PC133, x16 Only)
• Self Refresh
Standard
Low Power
-8E
-75
-7E
-6
Configuration
Refresh Count
Row Addressing
Bank Addressing
Column Addressing
3, 4,5
None
IT 3
Part Number Example:
MT48LC8M8A2TG-75:G
NOTE: 1.
2.
3.
4.
5.
Refer to Micron Technical Note: TN-48-05.
Off-center parting line.
Consult Micron for availability.
Not recommended for new designs.
Shown for PC100 compatibility.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
x16 x8 x4
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
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
Vss
DQ15 DQ7
VssQ DQ14 NC
DQ13 DQ6
VDDQ DQ12 NC
DQ11 DQ5
VssQ DQ10 NC
DQ9 DQ4
VDDQ DQ8 NC
Vss
NC
DQMH DQM
CLK
CKE
NC
A11
A9
A8
A7
A6
A5
A4
Vss
-
NC
NC
DQ3
NC
NC
NC
DQ2
NC
DQM
-
16 Meg x 4
4 Meg x 4 x 4 banks
4K
4K (A0-A11)
4 (BA0, BA1)
1K (A0-A9)
8 Meg x 8
2 Meg x 8 x 4 banks
4K
4K (A0-A11)
4 (BA0, BA1)
512 (A0-A8)
4 Meg x 16
1 Meg x 16 x 4 banks
4K
4K (A0-A11)
4 (BA0, BA1)
256 (A0-A7)
KEY TIMING PARAMETERS
:G
• Operating Temperature Range
Commercial (0°C to +70°C)
Industrial (-40°C to +85°C)
VDD
DQ0 DQ0
- VDDQ
NC DQ1
DQ1 DQ2
- VssQ
NC DQ3
DQ2 DQ4
- VDDQ
NC DQ5
DQ3 DQ6
- VssQ
NC DQ7
VDD
NC DQML
- WE#
- CAS#
- RAS#
CS#
BA0
BA1
A10
A0
A1
A2
A3
VDD
-
Note: The # symbol indicates signal is active LOW. A dash (–)
indicates x8 and x4 pin function is same as x16 pin function.
None
L
• Die Rev
-
SPEED
GRADE
CLOCK
FREQUENCY
-6
-7E
-75
-7E
-8E 3, 4, 5
-75
-8E 3, 4, 5
166 MHz
143 MHz
133 MHz
133 MHz
125 MHz
100 MHz
100 MHz
ACCESS TIME SETUP
CL = 2* CL = 3* TIME
–
–
–
5.4ns
–
6ns
6ns
5.5ns
5.4ns
5.4ns
–
6ns
–
–
1.5ns
1.5ns
1.5ns
1.5ns
2ns
1.5ns
2ns
HOLD
TIME
1ns
0.8ns
0.8ns
0.8ns
1ns
0.8ns
1ns
* CL = CAS (READ) latency
1
©2002 Micron Technology, Inc.
PRODUCTS AND SPECIFICATIONS DISCUSSED HEREIN ARE SUBJECT TO CHANGE BY MICRON WITHOUT NOTICE.
64Mb: x4, x8, x16
SDRAM
dress bits registered coincident with the READ or WRITE
command are used to select the starting column location for the burst access.
The SDRAM provides for programmable READ or
WRITE burst lengths of 1, 2, 4, or 8 locations, or the
full page, with a burst terminate option. An auto
precharge function may be enabled to provide a selftimed row precharge that is initiated at the end of the
burst sequence.
The 64Mb SDRAM uses an internal pipelined
architecture to achieve high-speed operation. This
architecture is compatible with the 2n rule of prefetch
architectures, but it also allows the column address to
be changed on every clock cycle to achieve a highspeed, fully random access. Precharging one bank
while accessing one of the other three banks will hide
the precharge cycles and provide seamless, highspeed, random-access operation.
The 64Mb SDRAM is designed to operate in 3.3V
memory systems. An auto refresh mode is provided,
along with a power-saving, power-down mode.
All inputs and outputs are LVTTL-compatible.
SDRAMs offer substantial advances in DRAM operating performance, including the ability to synchronously burst data at a high data rate with automatic
column-address generation, the ability to interleave
between internal banks in order to hide precharge time
and the capability to randomly change column
addresses on each clock cycle during a burst access.
64Mb SDRAM PART NUMBERS
PART NUMBER
MT48LC16M4A2TG
MT48LC8M8A2TG
MT48LC4M16A2TG
ARCHITECTURE
16 Meg x 4
8 Meg x 8
4 Meg x 16
GENERAL DESCRIPTION
The Micron® 64Mb SDRAM is a high-speed CMOS,
dynamic random-access memory containing
67,108,864 bits. It is internally configured as a quadbank DRAM with a synchronous interface (all signals
are registered on the positive edge of the clock signal,
CLK). Each of the x4’s 16,777,216-bit banks is organized as 4,096 rows by 1,024 columns by 4 bits. Each of
the x8’s 16,777,216-bit banks is organized as 4,096 rows
by 512 columns by 8 bits. Each of the x16’s 16,777,216bit banks is organized as 4,096 rows by 256 columns by
16 bits.
Read and write accesses to the SDRAM are burst
oriented; accesses start at a selected location and continue for a programmed number of locations in a programmed sequence. Accesses begin with the
registration of an ACTIVE command, which is then followed by a READ or WRITE command. The address bits
registered coincident with the ACTIVE command are
used to select the bank and row to be accessed (BA0,
BA1 select the bank; A0-A11 select the row). The ad-
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
2
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
TABLE OF CONTENTS
Functional Block Diagram – 16 Meg x 4 .................
Functional Block Diagram – 8 Meg x 8 .................
Functional Block Diagram – 4 Meg x 16 ...............
Pin Descriptions ...........................................................
4
5
6
7
Functional Description .............................................
Initialization ...........................................................
Register Definition .................................................
Mode Register ....................................................
Burst Length ................................................
Burst Type ....................................................
CAS Latency .................................................
Operating Mode ..........................................
Write Burst Mode ........................................
Commands ..............................................................
8
8
8
8
8
9
10
10
10
11
11
12
12
12
12
12
12
12
12
12
13
13
14
14
15
21
23
23
24
24
Truth Table 1 (Commands and DQM Operation) ........
Command Inhibit ............................................
No Operation (NOP) ........................................
Load Mode Register ..........................................
Active ..................................................................
Read ....................................................................
Write ...................................................................
Precharge ...........................................................
Auto Precharge ..................................................
Burst Terminate ................................................
Auto Refresh ......................................................
Self Refresh ........................................................
Operation ................................................................
Bank/Row Activation .......................................
Reads ...................................................................
Writes .................................................................
Precharge ...........................................................
Power-Down ......................................................
Clock Suspend ...................................................
Burst Read/Single Write ..................................
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
Concurrent Auto Precharge ........................... 25
Truth Table 2 (CKE) ...................................................... 27
Truth Table 3 (Current State, Same Bank) .................... 28
Truth Table 4 (Current State, Different Bank) ............... 30
Absolute Maximum Ratings ...................................... 32
DC Electrical Characteristics
and Operating Conditions ....................................... 32
IDD Specifications and Conditions ........................... 32
Capacitance .................................................................. 33
Electrical Characteristics and Recommended
Operating Conditions (Timing Table) ............ 34
Timing Waveforms
Initialize and Load Mode Register ......................
Power-Down Mode ...............................................
Clock Suspend Mode ............................................
Auto Refresh Mode ...............................................
Self Refresh Mode ..................................................
Reads
Read – Without Auto Precharge ...................
Read – With Auto Precharge ..........................
Single Read – Without Auto Precharge .......
Single Read – With Auto Precharge ..............
Alternating Bank Read Accesses .....................
Read – Full-Page Burst .....................................
Read – DQM Operation .................................
Writes
Write – Without Auto Precharge ..................
Write – With Auto Precharge ........................
Single Write – Without Auto Precharge ......
Single Write – With Auto Precharge .............
Alternating Bank Write Accesses ...................
Write – Full-Page Burst ....................................
Write – DQM Operation ................................
3
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
FUNCTIONAL BLOCK DIAGRAM
16 Meg x 4 SDRAM
CKE
CLK
COMMAND
DECODE
CS#
WE#
CAS#
RAS#
CONTROL
LOGIC
BANK3
BANK2
BANK1
MODE REGISTER
REFRESH 12
COUNTER
12
ROWADDRESS
MUX
12
12
BANK0
ROWADDRESS
LATCH
&
DECODER
4096
BANK0
MEMORY
ARRAY
(4,096 x 1,024 x 4)
1
DQM
SENSE AMPLIFIERS
4
4096
I/O GATING
DQM MASK LOGIC
READ DATA LATCH
WRITE DRIVERS
2
A0-A11,
BA0, BA1
14
ADDRESS
REGISTER
2
BANK
CONTROL
LOGIC
DATA
OUTPUT
REGISTER
4
4
1024
(x4)
1
DQ0-DQ3
DATA
INPUT
REGISTER
COLUMN
DECODER
10
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
COLUMNADDRESS
COUNTER/
LATCH
10
4
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
FUNCTIONAL BLOCK DIAGRAM
8 Meg x 8 SDRAM
CKE
CLK
COMMAND
DECODE
CS#
WE#
CAS#
RAS#
CONTROL
LOGIC
BANK3
BANK2
BANK1
MODE REGISTER
REFRESH 12
COUNTER
12
ROWADDRESS
MUX
12
12
BANK0
ROWADDRESS
LATCH
&
DECODER
4096
BANK0
MEMORY
ARRAY
(4,096 x 512 x 8)
1
DQM
SENSE AMPLIFIERS
8
4096
14
ADDRESS
REGISTER
2
DATA
OUTPUT
REGISTER
I/O GATING
DQM MASK LOGIC
READ DATA LATCH
WRITE DRIVERS
2
A0-A11,
BA0, BA1
1
BANK
CONTROL
LOGIC
8
8
512
(x8)
DQ0-DQ7
DATA
INPUT
REGISTER
COLUMN
DECODER
9
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
COLUMNADDRESS
COUNTER/
LATCH
9
5
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
FUNCTIONAL BLOCK DIAGRAM
4 Meg x 16 SDRAM
CKE
CLK
COMMAND
DECODE
CS#
WE#
CAS#
RAS#
CONTROL
LOGIC
BANK3
BANK2
BANK1
MODE REGISTER
REFRESH 12
COUNTER
12
ROWADDRESS
MUX
12
12
BANK0
ROWADDRESS
LATCH
&
DECODER
4096
BANK0
MEMORY
ARRAY
(4,096 x 256 x 16)
2
DQML,
DQMH
SENSE AMPLIFIERS
16
4096
I/O GATING
DQM MASK LOGIC
READ DATA LATCH
WRITE DRIVERS
2
A0-A11,
BA0, BA1
14
ADDRESS
REGISTER
2
BANK
CONTROL
LOGIC
DATA
OUTPUT
REGISTER
16
16
256
(x16)
2
DQ0-DQ15
DATA
INPUT
REGISTER
COLUMN
DECODER
8
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
COLUMNADDRESS
COUNTER/
LATCH
8
6
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
PIN DESCRIPTIONS
PIN NUMBERS
SYMBOL
TYPE
38
CLK
Input
Clock: CLK is driven by the system clock. All SDRAM input signals are
sampled on the positive edge of CLK. CLK also increments the internal
burst counter and controls the output registers.
DESCRIPTION
37
CKE
Input
Clock Enable: CKE activates (HIGH) and deactivates (LOW) the CLK
signal. Deactivating the clock provides PRECHARGE POWER-DOWN
and SELF REFRESH operation (all banks idle), ACTIVE POWER-DOWN
(row active in any bank) or CLOCK SUSPEND operation (burst/access in
progress). CKE is synchronous except after the device enters powerdown and self refresh modes, where CKE becomes asynchronous until
after exiting the same mode. The input buffers, including CLK, are
disabled during power-down and self refresh modes, providing low
standby power. CKE may be tied HIGH.
19
CS#
Input
Chip Select: CS# enables (registered LOW) and disables (registered
HIGH) the command decoder. All commands are masked when CS# is
registered HIGH. CS# provides for external bank selection on systems
with multiple banks. CS# is considered part of the command code.
16, 17, 18
WE#, CAS#,
RAS#
Input
Command Inputs: WE#, CAS#, and RAS# (along with CS#) define the
command being entered.
39
x4, x8: DQM
Input
15, 39
x16: DQML,
DQMH
Input/Output Mask: DQM is an input mask signal for write accesses and
an output enable signal for read accesses. Input data is masked when
DQM is sampled HIGH during a WRITE cycle. The output buffers are
placed in a High-Z state (two-clock latency) when DQM is sampled
HIGH during a READ cycle. On the x4 and x8, DQML (Pin 15) is a NC
and DQMH is DQM. On the x16, DQML corresponds to DQ0-DQ7 and
DQMH corresponds to DQ8-DQ15. DQML and DQMH are considered
same state when referenced as DQM.
20, 21
BA0, BA1
Input
Bank Address Inputs: BA0 and BA1 define to which bank the ACTIVE,
READ, WRITE or PRECHARGE command is being applied.
23-26, 29-34, 22, 35
A0-A11
Input
Address Inputs: A0-A11 are sampled during the ACTIVE command
(row-address A0-A11) and READ/WRITE command (column-address A0A9 [x4]; A0-A8 [x8]; A0-A7 [x16]; with A10 defining auto precharge) to
select one location out of the memory array in the respective bank.
A10 is sampled during a PRECHARGE command to determine if all
banks are to be precharged (A10[HIGH]) or bank selected by BA0,
BA1 (A1[LOW]). The address inputs also provide the op-code
during a LOAD MODE REGISTER command.
2, 4, 5, 7, 8, 10, 11, 13, 42, DQ0-DQ15 x16: I/O Data Input/Output: Data bus for x16 (4, 7, 10, 13, 42, 45, 48, and 51 are
44, 45, 47, 48, 50, 51, 53
NCs for x8; and 2, 4, 7, 8, 10, 13, 42, 45, 47, 48, 51, and 53 are NCs for x4).
2, 5, 8, 11, 44, 47, 50, 53 DQ0-DQ7
x8: I/O Data Input/Output: Data bus for x8 (2, 8, 47, 53 are NCs for x4).
5, 11, 44, 50
DQ0-DQ3
x4: I/O Data Input/Output: Data bus for x4.
40
NC
–
No Connect: These pins should be left unconnected.
36
NC
–
Address input (A12) for the 256Mb and 512Mb devices
3, 9, 43, 49
6, 12, 46, 52
VDDQ
VSSQ
1, 14, 27
VDD
Supply Power Supply: +3.3V ±0.3V.
28, 41, 54
VSS
Supply Ground.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
Supply DQ Power: Isolated DQ power on the die for improved noise immunity.
Supply DQ Ground: Isolated DQ ground on the die for improved noise
immunity.
7
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
FUNCTIONAL DESCRIPTION
Register Definition
In general, the 64Mb SDRAMs (4 Meg x 4 x 4 banks,
2 Meg x 8 x 4 banks and 1 Meg x 16 x 4 banks) are quadbank DRAMs which operate at 3.3V and include a synchronous interface (all signals are registered on the
positive edge of the clock signal, CLK). Each of the x4’s
16,777,216-bit banks is organized as 4,096 rows by 1,024
columns by 4 bits. Each of the x8’s 16,777,216-bit banks
is organized as 4,096 rows by 512 columns by 8 bits.
Each of the x16’s 16,777,216-bit banks is organized as
4,096 rows by 256 columns by 16 bits.
Read and write accesses to the SDRAM are burst
oriented; accesses start at a selected location and continue for a programmed number of locations in a programmed sequence. Accesses begin with the registration of an ACTIVE command which is then followed by
a READ or WRITE command. The address bits registered coincident with the ACTIVE command are used
to select the bank and row to be accessed (BA0 and BA1
select the bank, A0-A11 select the row). The address
bits (x4: A0-A9; x8: A0-A8; x16: A0-A7) registered coincident with the READ or WRITE command are used to
select the starting column location for the burst access.
Prior to normal operation, the SDRAM must be initialized. The following sections provide detailed information covering device initialization, register definition, command descriptions and device operation.
MODE REGISTER
The mode register is used to define the specific mode
of operation of the SDRAM. This definition includes
the selection of a burst length, a burst type, a CAS
latency, an operating mode and a write burst mode, as
shown in Figure 1. The mode register is programmed
via the LOAD MODE REGISTER command and will retain the stored information until it is programmed again
or the device loses power.
Mode register bits M0-M2 specify the burst length,
M3 specifies the type of burst (sequential or interleaved), M4-M6 specify the CAS latency, M7 and M8
specify the operating mode, M9 specifies the WRITE
burst mode, and M10 and M11 are reserved for future
use.
The mode register must be loaded when all banks
are idle, and the controller must wait the specified time
before initiating the subsequent operation. Violating
either of these requirements will result in unspecified
operation.
Burst Length
Read and write accesses to the SDRAM are burst
oriented, with the burst length being programmable,
as shown in Figure 1. The burst length determines the
maximum number of column locations that can be accessed for a given READ or WRITE command. Burst
lengths of 1, 2, 4, or 8 locations are available for both the
sequential and the interleaved burst types, and a fullpage burst is available for the sequential type. The
full-page burst is used in conjunction with the BURST
TERMINATE command to generate arbitrary burst
lengths.
Reserved states should not be used, as unknown
operation or incompatibility with future versions may
result.
When a READ or WRITE command is issued, a block
of columns equal to the burst length is effectively selected. All accesses for that burst take place within this
block, meaning that the burst will wrap within the block
if a boundary is reached. The block is uniquely selected by A1-A9 (x4), A1-A8 (x8) or A1-A7 (x16) when the
burst length is set to two; by A2-A9 (x4), A2-A8 (x8) or
A2-A7 (x16) when the burst length is set to four; and by
A3-A9 (x4), A3-A8 (x8) or A3-A7 (x16) when the burst
length is set to eight. The remaining (least significant)
address bit(s) is (are) used to select the starting location within the block. Full-page bursts wrap within the
page if the boundary is reached.
Initialization
SDRAMs must be powered up and initialized in a
predefined manner. Operational procedures other
than those specified may result in undefined operation. Once power is applied to VDD and VDDQ (simultaneously) and the clock is stable (stable clock is defined
as a signal cycling within timing constraints specified
for the clock pin), the SDRAM requires a 100µs delay
prior to issuing any command other than a COMMAND
INHIBIT or a NOP. Starting at some point during this
100µs period and continuing at least through the end
of this period, COMMAND INHIBIT or NOP commands
should be applied.
Once the 100µs delay has been satisfied with at
least one COMMAND INHIBIT or NOP command having been applied, a PRECHARGE command should be
applied. All banks must be precharged, thereby placing the device in the all banks idle state.
Once in the idle state, two AUTO REFRESH cycles
must be performed. After the AUTO REFRESH cycles
are complete, the SDRAM is ready for mode register
programming. Because the mode register will power
up in an unknown state, it should be loaded prior to
applying any operational command.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
8
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
Burst Type
Accesses within a given burst may be programmed
to be either sequential or interleaved; this is referred to
as the burst type and is selected via bit M3.
The ordering of accesses within a burst is determined by the burst length, the burst type and the starting column address, as shown in Table 1.
Table 1
Burst Definition
Burst
Length
2
Figure 1
Mode Register Definition
A11 A10
11
10
A9
9
Reserved* WB
A8
8
A6
A7
6
7
Op Mode
A5
5
A4
A3
4
CAS Latency
3
1
2
BT
A1
A2
0
4
Address Bus
A0
Mode Register (Mx)
Burst Length
8
*Should program
M11, M10 = “0, 0”
to ensure compatibility
with future devices.
Burst Length
M2 M1 M0
M3 = 0
M3 = 1
0
0
0
1
1
0
0
1
2
2
0
1
0
4
4
0
1
1
8
8
1
0
0
Reserved
Reserved
1
0
1
Reserved
Reserved
1
1
0
Reserved
Reserved
1
1
1
Full Page
Reserved
0
Sequential
1
Interleaved
M6 M5 M4
CAS Latency
0
0
0
Reserved
0
0
1
Reserved
0
1
0
2
0
1
1
3
1
0
0
Reserved
1
0
1
Reserved
1
1
0
Reserved
1
1
1
Reserved
M8
M7
M6-M0
Operating Mode
0
0
Defined
Standard Operation
-
-
-
M9
Write Burst Mode
0
Programmed Burst Length
1
Single Location Access
A0
0
1
A1 A0
0
0
0
1
1
0
1
1
A2 A1 A0
0
0
0
0
0
1
0
1
0
0
1
1
1
0
0
1
0
1
1
1
0
1
1
1
n = A0-A9/8/7
(location 0-y)
0-1
1-0
0-1
1-0
0-1-2-3
1-2-3-0
2-3-0-1
3-0-1-2
0-1-2-3
1-0-3-2
2-3-0-1
3-2-1-0
0-1-2-3-4-5-6-7
1-2-3-4-5-6-7-0
2-3-4-5-6-7-0-1
3-4-5-6-7-0-1-2
4-5-6-7-0-1-2-3
5-6-7-0-1-2-3-4
6-7-0-1-2-3-4-5
7-0-1-2-3-4-5-6
Cn, Cn + 1, Cn + 2
Cn + 3, Cn + 4...
…Cn - 1,
Cn…
0-1-2-3-4-5-6-7
1-0-3-2-5-4-7-6
2-3-0-1-6-7-4-5
3-2-1-0-7-6-5-4
4-5-6-7-0-1-2-3
5-4-7-6-1-0-3-2
6-7-4-5-2-3-0-1
7-6-5-4-3-2-1-0
Not Supported
NOTE: 1. For full-page accesses: y = 1,024 (x4); y = 512 (x8);
y = 256 (x16).
2. For a burst length of two, A1-A9 (x4), A1-A8 (x8),
or A1-A7 (x16) select the block-of-two burst; A0
selects the starting column within the block.
3. For a burst length of four, A2-A9 (x4), A2-A8 (x8),
or A2-A7 (x16) select the block-of-four burst; A0A1 select the starting column within the block.
4. For a burst length of eight, A3-A9 (x4), A3-A8 (x8),
or A3-A7 (x16) select the block-of-eight burst; A0A2 select the starting column within the block.
5. For a full-page burst, the full row is selected and
A0-A9 (x4), A0-A8 (x8), or A0-A7 (x16) select the
starting column.
6. Whenever a boundary of the block is reached
within a given sequence above, the following
access wraps within the block.
7. For a burst length of one, A0-A9 (x4), A0-A8 (x8),
or A0-A7 (x16) select the unique column to be
accessed, and mode register bit M3 is ignored.
Burst Type
M3
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
Full
Page
(y)
Starting Column
Order of Accesses Within a Burst
Address
Type = Sequential Type = Interleaved
All other states reserved
9
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64Mb: x4, x8, x16
SDRAM
CAS Latency
The CAS latency is the delay, in clock cycles, between the registration of a READ command and the
availability of the first piece of output data. The latency can be set to two or three clocks.
If a READ command is registered at clock edge n,
and the latency is m clocks, the data will be available by
clock edge n + m. The DQs will start driving as a result of
the clock edge one cycle earlier (n + m - 1), and provided
that the relevant access times are met, the data will be
valid by clock edge n + m. For example, assuming that
the clock cycle time is such that all relevant access times
are met, if a READ command is registered at T0 and the
latency is programmed to two clocks, the DQs will start
driving after T1 and the data will be valid by T2, as
shown in Figure 2. Table 2 indicates the operating frequencies at which each CAS latency setting can be used.
Reserved states should not be used as unknown
operation or incompatibility with future versions
may result.
Operating Mode
The normal operating mode is selected by setting
M7 and M8 to zero; the other combinations of values for
M7 and M8 are reserved for future use and/or test
modes. The programmed burst length applies to both
READ and WRITE bursts.
Test modes and reserved states should not be used
because unknown operation or incompatibility with
future versions may result.
Write Burst Mode
When M9 = 0, the burst length programmed via
M0-M2 applies to both READ and WRITE bursts; when
M9 = 1, the programmed burst length applies to
READ bursts, but write accesses are single-location
(nonburst) accesses.
Table 2
CAS Latency
ALLOWABLE OPERATING
FREQUENCY (MHz)
Figure 2
CAS Latency
T0
T1
T2
READ
NOP
NOP
SPEED
-6
-7E
-75
-8E
T3
CLK
COMMAND
tLZ
tOH
CAS
LATENCY = 2
–
≤ 133
≤ 100
≤ 100
CAS
LATENCY = 3
≤ 166
≤ 143
≤ 133
≤ 125
DOUT
DQ
tAC
CAS Latency = 2
T0
T1
T2
T3
T4
READ
NOP
NOP
NOP
CLK
COMMAND
tLZ
tOH
DOUT
DQ
tAC
CAS Latency = 3
DON’T CARE
UNDEFINED
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
Commands
Truth Table 1 provides a quick reference of
available commands. This is followed by a written description of each command. Three additional Truth
Tables appear following the Operation section; these
tables provide current state/next state information.
TRUTH TABLE 1 – COMMANDS AND DQM OPERATION
(Note: 1)
NAME (FUNCTION)
CS# RAS# CAS# WE# DQM
ADDR
DQs
X
X
X
X
X
X
Bank/Row
X
3
H
L/H8
Bank/Col
X
4
L
L
L/H8
Bank/Col
Valid
4
H
H
L
X
X
Active
L
L
H
L
X
Code
X
5
L
L
L
H
X
X
X
6, 7
LOAD MODE REGISTER
L
L
L
L
X
Op-Code
X
2
Write Enable/Output Enable
–
–
–
–
L
–
Active
8
Write Inhibit/Output High-Z
–
–
–
–
H
–
High-Z
8
COMMAND INHIBIT (NOP)
H
X
X
X
X
NO OPERATION (NOP)
L
H
H
H
ACTIVE (Select bank and activate row)
L
L
H
H
READ (Select bank and column, and start READ burst)
L
H
L
WRITE (Select bank and column, and start WRITE burst)
L
H
BURST TERMINATE
L
PRECHARGE (Deactivate row in bank or banks)
AUTO REFRESH or SELF REFRESH
(Enter self refresh mode)
NOTE: 1.
2.
3.
4.
5.
6.
7.
8.
NOTES
CKE is HIGH for all commands shown except SELF REFRESH.
A0-A11 define the op-code written to the mode register.
A0-A11 provide row address, and BA0, BA1 determine which bank is made active.
A0-A9 (x4), A0-A8 (x8), or A0-A7 (x16) provide column address; A10 (HIGH) enables the auto precharge feature
(nonpersistent), while A10 (LOW) disables the auto precharge feature; BA0, BA1 determine which bank is being read
from or written to.
A10 (LOW): BA0, BA1 determine the bank being precharged. A10 HIGH: All banks precharged and BA0, BA1 are “Don’t
Care.”
This command is AUTO REFRESH if CKE is (HIGH), SELF REFRESH if CKE is LOW.
Internal refresh counter controls row addressing; all inputs and I/Os are “Don’t Care” except for CKE.
Activates or deactivates the DQs during WRITEs (zero-clock delay) and READs (two-clock delay).
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
COMMAND INHIBIT
The COMMAND INHIBIT function prevents new
commands from being executed by the SDRAM, regardless of whether the CLK signal is enabled. The
SDRAM is effectively deselected. Operations already
in progress are not affected.
precharge is selected, the row being accessed will be
precharged at the end of the WRITE burst; if auto
precharge is not selected, the row will remain open for
subsequent accesses. Input data appearing on the DQs
is written to the memory array subject to the DQM input logic level appearing coincident with the data. If a
given DQM signal is registered LOW, the corresponding data will be written to memory; if the DQM signal is
registered HIGH, the corresponding data inputs will
be ignored, and a WRITE will not be executed to that
byte/column location.
NO OPERATION (NOP)
The NO OPERATION (NOP) command is used to
perform a NOP to an SDRAM which is selected (CS# is
LOW). This prevents unwanted commands from being
registered during idle or wait states. Operations already
in progress are not affected.
PRECHARGE
The PRECHARGE command is used to deactivate
the open row in a particular bank or the open row in all
banks. The bank(s) will be available for a subsequent
row access a specified time (tRP) after the PRECHARGE
command is issued. Input A10 determines whether
one or all banks are to be precharged, and in the case
where only one bank is to be precharged, inputs BA0,
BA1 select the bank. Otherwise BA0, BA1 are treated as
“Don’t Care.” Once a bank has been precharged, it is in
the idle state and must be activated prior to any READ
or WRITE commands being issued to that bank.
LOAD MODE REGISTER
The mode register is loaded via inputs A0-A11. See
mode register heading in the Register Definition section.
The LOAD MODE REGISTER command can only be issued when all banks are idle, and a subsequent executable command cannot be issued until tMRD is met.
ACTIVE
The ACTIVE command is used to open (or activate)
a row in a particular bank for a subsequent access. The
value on the BA0, BA1 inputs selects the bank, and the
address provided on inputs A0-A11 selects the row.
This row remains active (or open) for accesses until a
PRECHARGE command is issued to that bank.
A PRECHARGE command must be issued before opening a different row in the same bank.
AUTO PRECHARGE
Auto precharge is a feature which performs the
same individual-bank PRECHARGE function described above, without requiring an explicit command.
This is accomplished by using A10 to enable auto
precharge in conjunction with a specific READ or WRITE
command. A precharge of the bank/row that is addressed with the READ or WRITE command is automatically performed upon completion of the READ or
WRITE burst, except in the full-page burst mode, where
auto precharge does not apply. Auto precharge is nonpersistent in that it is either enabled or disabled for
each individual READ or WRITE command.
Auto precharge ensures that the precharge is initiated at the earliest valid stage within a burst. The user
must not issue another command to the same bank
until the precharge time (tRP) is completed. This is
determined as if an explicit PRECHARGE command
was issued at the earliest possible time, as described
for each burst type in the Operation section of this data
sheet.
READ
The READ command is used to initiate a burst read
access to an active row. The value on the BA0, BA1
inputs selects the bank, and the address provided on
inputs A0-A9 (x4), A0-A8 (x8), or A0-A7 (x16) selects the
starting column location. The value on input A10 determines whether or not auto precharge is used. If auto
precharge is selected, the row being accessed will be
precharged at the end of the READ burst; if auto
precharge is not selected, the row will remain open for
subsequent accesses. Read data appears on the DQs
subject to the logic level on the DQM inputs two clocks
earlier. If a given DQM signal was registered HIGH, the
corresponding DQs will be High-Z two clocks later; if
the DQM signal was registered LOW, the DQs will provide valid data.
WRITE
The WRITE command is used to initiate a burst write
access to an active row. The value on the BA0, BA1
inputs selects the bank, and the address provided on
inputs A0-A9 (x4), A0-A8 (x8), or A0-A7 (x16) selects the
starting column location. The value on input A10 determines whether or not auto precharge is used. If auto
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
BURST TERMINATE
The BURST TERMINATE command is used to truncate either fixed-length or full-page bursts. The most
recently registered READ or WRITE command prior to
the BURST TERMINATE command will be truncated,
as shown in the Operation section of this data sheet.
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64Mb: x4, x8, x16
SDRAM
AUTO REFRESH
AUTO REFRESH is used during normal operation of
the SDRAM and is analagous to CAS#-BEFORE-RAS#
(CBR) REFRESH in conventional DRAMs. This command is nonpersistent, so it must be issued each time
a refresh is required. All active banks must be
PRECHARGED prior to issuing an AUTO REFRESH command. The AUTO REFRESH command should not be
issued until the minimum tRP has been met after the
PRECHARGE command as shown in the operation section.
The addressing is generated by the internal refresh
controller. This makes the address bits “Don’t Care”
during an AUTO REFRESH command. The 64Mb
SDRAM requires 4,096 AUTO REFRESH cycles every
64ms (tREF), regardless of width option. Providing a
distributed AUTO REFRESH command every 15.625µs
will meet the refresh requirement and ensure that each
row is refreshed. Alternatively, 4,096 AUTO REFRESH
commands can be issued in a burst at the minimum
cycle rate (tRC), once every 64ms.
SDRAM retains data without external clocking.
The SELF REFRESH command is initiated like an AUTO
REFRESH command except CKE is disabled (LOW).
Once the SELF REFRESH command is registered, all
the inputs to the SDRAM become “Don’t Care,” with
the exception of CKE, which must remain LOW.
Once self refresh mode is engaged, the SDRAM provides its own internal clocking, causing it to perform its
own AUTO REFRESH cycles. The SDRAM must remain
in self refresh mode for a minimum period equal to
tRAS and may remain in self refresh mode for an indefinite period beyond that.
The procedure for exiting self refresh requires a sequence of commands. First, CLK must be stable (stable
clock is defined as a signal cycling within timing constraints specified for the clock pin) prior to CKE going
back HIGH. Once CKE is HIGH, the SDRAM must have
NOP commands issued (a minimum of two clocks) for
tXSR, because time is required for the completion of
any internal refresh in progress.
Upon exiting the self refresh mode, AUTO REFRESH
commands must be issued every 15.625µs or less as
both SELF REFRESH and AUTO REFRESH utilize the
row refresh counter.
SELF REFRESH
The SELF REFRESH command can be used to retain
data in the SDRAM, even if the rest of the system is
powered down. When in the self refresh mode, the
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
Operation
Figure 3
Activating a Specific Row in a
Specific Bank
BANK/ROW ACTIVATION
Before any READ or WRITE commands can be issued to a bank within the SDRAM, a row in that bank
must be “opened.” This is accomplished via the ACTIVE command, which selects both the bank and the
row to be activated (see Figure 3).
After opening a row (issuing an ACTIVE command),
a READ or WRITE command may be issued to that row,
subject to the tRCD specification. tRCD (MIN) should
be divided by the clock period and rounded up to the
next whole number to determine the earliest clock edge
after the ACTIVE command on which a READ or WRITE
command can be entered. For example, a tRCD specification of 20ns with a 125 MHz clock (8ns period) results
in 2.5 clocks, rounded to 3. This is reflected in Figure 4,
which covers any case where 2 < tRCD (MIN)/tCK ≤ 3.
(The same procedure is used to convert other specification limits from time units to clock cycles).
A subsequent ACTIVE command to a different row
in the same bank can only be issued after the previous
active row has been “closed” (precharged). The minimum time interval between successive ACTIVE commands to the same bank is defined by tRC.
A subsequent ACTIVE command to another bank
can be issued while the first bank is being accessed,
which results in a reduction of total row-access overhead. The minimum time interval between successive
ACTIVE commands to different banks is defined by
t RRD.
CLK
CKE
HIGH
CS#
RAS#
CAS#
WE#
ROW
ADDRESS
A0–A10, A11
BANK
ADDRESS
BA0, BA1
Figure 4
Example: Meeting tRCD (MIN) When 2 < tRCD (MIN)/tCK < 3
T0
T1
T2
NOP
NOP
T3
T4
CLK
COMMAND
ACTIVE
READ or
WRITE
tRCD
DON’T CARE
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
READs
READ bursts are initiated with a READ command,
as shown in Figure 5.
The starting column and bank addresses are provided with the READ command, and auto precharge is
either enabled or disabled for that burst access. If auto
precharge is enabled, the row being accessed is
precharged at the completion of the burst. For the generic READ commands used in the following illustrations, auto precharge is disabled.
During READ bursts, the valid data-out element
from the starting column address will be available following the CAS latency after the READ command. Each
subsequent data-out element will be valid by the next
positive clock edge. Figure 6 shows general timing for
each possible CAS latency setting.
Upon completion of a burst, assuming no other commands have been initiated, the DQs will go High-Z. A
full-page burst will continue until terminated. (At the
end of the page, it will wrap to column 0 and continue.)
Data from any READ burst may be truncated with a
subsequent READ command, and data from a fixedlength READ burst may be immediately followed by
data from a READ command. In either case, a continuous flow of data can be maintained. The first data element from the new burst follows either the last element of a completed burst or the last desired data element of a longer burst which is being truncated.
The new READ command should be issued x cycles
Figure 5
READ Command
Figure 6
CAS Latency
CLK
T0
T1
T2
T3
READ
NOP
NOP
CLK
CKE
HIGH
COMMAND
tLZ
CS#
tOH
DOUT
DQ
tAC
CAS Latency = 2
RAS#
CAS#
T0
T1
T2
T3
T4
READ
NOP
NOP
NOP
CLK
WE#
COMMAND
A0-A9: x4
A0-A8: x8
A0-A7: x16
tLZ
COLUMN
ADDRESS
tOH
DOUT
DQ
tAC
A11: x4
A9, A11: x8
A8, A9, A11: x16
CAS Latency = 3
DON’T CARE
ENABLE AUTO PRECHARGE
UNDEFINED
A10
DISABLE AUTO PRECHARGE
BA0,1
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
BANK
ADDRESS
15
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64Mb: x4, x8, x16
SDRAM
before the clock edge at which the last desired data
element is valid, where x equals the CAS latency minus
one. This is shown in Figure 7 for CAS latencies of two
and three; data element n + 3 is either the last of a burst
of four or the last desired of a longer burst. The 64Mb
SDRAM uses a pipelined architecture and therefore
does not require the 2n rule associated with a prefetch
architecture. A READ command can be initiated on any
clock cycle following a previous READ command. Fullspeed random read accesses can be performed to the
same bank, as shown in Figure 8, or each subsequent
READ may be performed to a different bank.
Figure 7
Consecutive READ Bursts
T0
T1
T2
T3
T4
T5
T6
CLK
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
NOP
READ
NOP
X = 1 cycle
BANK,
COL b
DOUT
n+2
DOUT
n+1
DOUT
n
DQ
DOUT
n+3
DOUT
b
CAS Latency = 2
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
READ
NOP
NOP
NOP
X = 2 cycles
BANK,
COL b
DOUT
n
DQ
DOUT
n+1
DOUT
n+2
DOUT
n+3
DOUT
b
CAS Latency = 3
TRANSITIONING DATA
DON’T CARE
NOTE: Each READ command may be to any bank. DQM is LOW.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
Figure 8
Random READ Accesses
T0
T1
T2
T3
T4
T5
CLK
COMMAND
READ
READ
READ
READ
ADDRESS
BANK,
COL n
BANK,
COL a
BANK,
COL x
BANK,
COL m
DOUT
n
DQ
NOP
NOP
DOUT
x
DOUT
a
DOUT
m
CAS Latency = 2
T0
T1
T2
T3
T4
T5
T6
CLK
COMMAND
READ
READ
READ
READ
ADDRESS
BANK,
COL n
BANK,
COL a
BANK,
COL x
BANK,
COL m
NOP
DOUT
a
DOUT
n
DQ
NOP
DOUT
x
NOP
DOUT
m
CAS Latency = 3
TRANSITIONING DATA
DON’T CARE
NOTE: Each READ command may be to any bank. DQM is LOW.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
Data from any READ burst may be truncated with a
subsequent WRITE command, and data from a fixedlength READ burst may be immediately followed by
data from a WRITE command (subject to bus turnaround limitations). The WRITE burst may be initiated
on the clock edge immediately following the last (or last
desired) data element from the READ burst, provided
that I/O contention can be avoided. In a given system
design, there may be a possibility that the device driving the input data will go Low-Z before the SDRAM DQs
go High-Z. In this case, at least a single-cycle delay
should occur between the last read data and the WRITE
command.
The DQM input is used to avoid I/O contention, as
shown in Figures 9 and 10. The DQM signal must be
asserted (HIGH) at least two clocks prior to the WRITE
command (DQM latency is two clocks for output
buffers) to suppress data-out from the READ. Once the
WRITE command is registered, the DQs will go High-Z
(or remain High-Z), regardless of the state of the DQM
signal, provided the DQM was active on the clock just
prior to the WRITE command that truncated the READ
command. If not, the second WRITE will be an invalid
WRITE. For example, if DQM was LOW during T4 in
Figure 10, then the WRITEs at T5 and T7 would be
valid, while the WRITE at T6 would be invalid.
The DQM signal must be de-asserted prior to the
WRITE command (DQM latency is zero clocks for input
buffers) to ensure that the written data is not masked.
Figure 9 shows the case where the clock frequency allows for bus contention to be avoided without adding a
NOP cycle, and Figure 10 shows the case where the
additional NOP is needed.
Figure 9
READ to WRITE
Figure 10
READ to WRITE With
Extra Clock Cycle
T0
T1
T2
T3
T4
T0
CLK
T1
T2
T3
T4
DQM
DQM
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
WRITE
BANK,
COL b
COMMAND
READ
ADDRESS
BANK,
COL n
tCK
DQ
DOUT n
DQ
NOP
NOP
NOP
NOP
BANK,
COL b
DOUT n
DIN b
TRANSITIONING DATA
DON’T CARE
NOTE:
A CAS latency of three is used for illustration. The READ
command may be to any bank, and the WRITE command
may be to any bank. If a burst of one is used, then DQM is
not required.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
DIN b
tDS
tDS
TRANSITIONING DATA
WRITE
tHZ
tHZ
NOTE:
T5
CLK
18
DON’T CARE
A CAS latency of three is used for illustration. The READ command
may be to any bank, and the WRITE command may be to any bank.
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64Mb: x4, x8, x16
SDRAM
A fixed-length READ burst may be followed by, or
truncated with, a PRECHARGE command to the same
bank (provided that auto precharge was not activated), and a full-page burst may be truncated with a
PRECHARGE command to the same bank. The
PRECHARGE command should be issued x cycles before the clock edge at which the last desired data element is valid, where x equals the CAS latency minus
one. This is shown in Figure 11 for each possible CAS
latency; data element n + 3 is either the last of a burst of
four or the last desired of a longer burst. Following the
PRECHARGE command, a subsequent command to
the same bank cannot be issued until tRP is met. Note
that part of the row precharge time is hidden during
the access of the last data element(s).
In the case of a fixed-length burst being executed to
completion, a PRECHARGE command issued at the
optimum time (as described above) provides the same
operation that would result from the same fixed-length
burst with auto precharge. The disadvantage of the
Figure 11
READ to PRECHARGE
T0
T1
T2
T3
T4
T5
T6
T7
CLK
t RP
COMMAND
READ
NOP
NOP
NOP
PRECHARGE
NOP
NOP
ACTIVE
X = 1 cycle
ADDRESS
BANK
(a or all)
BANK a,
COL n
DOUT
n
DQ
BANK a,
ROW
DOUT
n+2
DOUT
n+1
DOUT
n+3
CAS Latency = 2
T0
T1
T2
T3
T4
T5
T6
T7
CLK
t RP
COMMAND
READ
NOP
NOP
NOP
PRECHARGE
NOP
NOP
ACTIVE
X = 2 cycles
ADDRESS
BANK
(a or all)
BANK a,
COL n
DOUT
n
DQ
DOUT
n+1
BANK a,
ROW
DOUT
n+2
DOUT
n+3
CAS Latency = 3
TRANSITIONING DATA
DON’T CARE
NOTE: DQM is LOW.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
19
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64Mb: x4, x8, x16
SDRAM
PRECHARGE command is that it requires that the command and address buses be available at the appropriate time to issue the command; the advantage of the
PRECHARGE command is that it can be used to truncate fixed-length or full-page bursts.
Full-page READ bursts can be truncated with the
BURST TERMINATE command, and fixed-length READ
bursts may be truncated with a BURST TERMINATE
command, provided that auto precharge was not activated. The BURST TERMINATE command should be
issued x cycles before the clock edge at which the last
desired data element is valid, where x equals the CAS
latency minus one. This is shown in Figure 12 for each
possible CAS latency; data element n + 3 is the last
desired data element of a longer burst.
Figure 12
Terminating a READ Burst
T0
T1
T2
T3
T4
T5
T6
CLK
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
BURST
TERMINATE
NOP
NOP
X = 1 cycle
DOUT
n+2
DOUT
n+1
DOUT
n
DQ
DOUT
n+3
CAS Latency = 2
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
BURST
TERMINATE
NOP
NOP
NOP
X = 2 cycles
DOUT
n
DQ
DOUT
n+1
DOUT
n+2
DOUT
n+3
CAS Latency = 3
TRANSITIONING DATA
DON’T CARE
NOTE: DQM is LOW.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
WRITEs
WRITE bursts are initiated with a WRITE command,
as shown in Figure 13.
The starting column and bank addresses are
provided with the WRITE command, and auto
precharge is either enabled or disabled for that access.
If auto precharge is enabled, the row being accessed is
precharged at the completion of the burst. For the generic WRITE commands used in the following illustrations, auto precharge is disabled.
During WRITE bursts, the first valid data-in element will be registered coincident with the WRITE command. Subsequent data elements will be registered on
each successive positive clock edge. Upon completion
of a fixed-length burst, assuming no other commands
have been initiated, the DQs will remain High-Z and
any additional input data will be ignored (see Figure
14). A full-page burst will continue until terminated.
(At the end of the page, it will wrap to column 0 and
continue.)
Data for any WRITE burst may be truncated with a
subsequent WRITE command, and data for a fixedlength WRITE burst may be immediately followed by
data for a WRITE command. The new WRITE command
can be issued on any clock following the previous WRITE
command, and the data provided coincident with the
new command applies to the new command.
An example is shown in Figure 15. Data n + 1 is either
the last of a burst of two or the last desired of a longer
burst. The 64Mb SDRAM uses a pipelined architecture
and therefore does not require the 2n rule associated
with a prefetch architecture. A WRITE command can
be initiated on any clock cycle following a previous
WRITE command. Full-speed random write accesses
within a page can be performed to the same bank, as
shown in Figure 16, or each subsequent WRITE may be
performed to a different bank.
Figure 14
WRITE Burst
T0
T1
T2
T3
COMMAND
WRITE
NOP
NOP
NOP
ADDRESS
BANK,
COL n
CLK
DQ
Figure 13
WRITE Command
DIN
n
DIN
n+1
TRANSITIONING DATA
DON’T CARE
NOTE: Burst length = 2. DQM is LOW.
CLK
CKE
HIGH
Figure 15
WRITE to WRITE
CS#
RAS#
T0
T1
T2
COMMAND
WRITE
NOP
WRITE
ADDRESS
BANK,
COL n
CLK
CAS#
WE#
A0-A9: x4
A0-A8: x8
A0-A7: x16
BANK,
COL b
COLUMN
ADDRESS
DQ
A11: x4
A9, A11: x8
A8, A9, A11: x16
DIN
n
DIN
n+1
TRANSITIONING DATA
ENABLE AUTO PRECHARGE
DIN
b
DON’T CARE
A10
NOTE: DQM is LOW. Each WRITE command may
be to any bank.
DISABLE AUTO PRECHARGE
BA0,1
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
BANK
ADDRESS
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64Mb: x4, x8, x16
SDRAM
tWR
Data for any WRITE burst may be truncated with a
subsequent READ command, and data for a fixedlength WRITE burst may be immediately followed by a
subsequent READ command. Once the READ command is registered, the data inputs will be ignored, and
WRITEs will not be executed. An example is shown in
Figure 17. Data n + 1 is either the last of a burst of two or
the last desired of a longer burst.
Data for a fixed-length WRITE burst may be followed by, or truncated with, a PRECHARGE command
to the same bank (provided that auto precharge was
not activated), and a full-page WRITE burst may be
truncated with a PRECHARGE command to the same
bank. The PRECHARGE command should be issued
after the clock edge at which the last desired input
data element is registered. The auto precharge mode
requires a tWR of at least one clock plus time, regardless
of frequency. In addition, when truncating a WRITE
burst, the DQM signal must be used to mask input data
for the clock edge prior to, and the clock edge coincident with, the PRECHARGE command. An example is
shown in Figure 18. Data n + 1 is either the last of a burst
of two or the last desired of a longer burst. Following the
PRECHARGE command, a subsequent command to
the same bank cannot be issued until tRP is met.
In the case of a fixed-length burst being executed to
completion, a PRECHARGE command issued at the
optimum time (as described above) provides the same
operation that would result from the same fixed-length
burst with auto precharge. The disadvantage of the
PRECHARGE command is that it requires that the command and address buses be available at the appropriate time to issue the command; the advantage of the
PRECHARGE command is that it can be used to truncate fixed-length or full-page bursts.
Figure 16
Random WRITE Cycles
T0
T1
T2
T3
COMMAND
WRITE
WRITE
WRITE
WRITE
ADDRESS
BANK,
COL n
BANK,
COL a
BANK,
COL x
BANK,
COL m
CLK
Figure 18
WRITE to PRECHARGE
T0
T1
T2
T3
NOP
PRECHARGE
NOP
T4
T5
T6
NOP
ACTIVE
NOP
CLK
DIN
n
DQ
DIN
a
DIN
x
TRANSITIONING DATA
DIN
m
tWR @ tCLK ≥ 15ns
DQM
DON’T CARE
t RP
COMMAND
ADDRESS
Figure 17
WRITE to READ
T0
T1
T2
T3
WRITE
BANK
(a or all)
BANK a,
COL n
BANK a,
ROW
t WR
DQ
T4
T5
DIN
n
DIN
n+1
tWR = tCLK < 15ns
CLK
DQM
COMMAND
WRITE
NOP
READ
NOP
NOP
t RP
NOP
COMMAND
ADDRESS
BANK,
COL n
ADDRESS
BANK,
COL b
WRITE
NOP
NOP
PRECHARGE
NOP
BANK
(a or all)
BANK a,
COL n
NOP
ACTIVE
BANK a,
ROW
t WR
DQ
DIN
n
DIN
n+1
DOUT
b
DQ
DOUT
b+1
DIN
n
DIN
n+1
TRANSITIONING DATA
TRANSITIONING DATA
DON’T CARE
DON’T CARE
NOTE: DQM could remain LOW in this example if the WRITE burst is a fixed length of two.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
PRECHARGE
The PRECHARGE command (Figure 20) is used to
deactivate the open row in a particular bank or the
open row in all banks. The bank(s) will be available for
a subsequent row access some specified time (tRP) after the PRECHARGE command is issued. Input A10
determines whether one or all banks are to be
precharged, and in the case where only one bank is to
be precharged, inputs BA0, BA1 select the bank. When
all banks are to be precharged, inputs BA0, BA1 are
treated as “Don’t Care.” Once a bank has been
precharged, it is in the idle state and must be activated
prior to any READ or WRITE commands being issued to
that bank.
Fixed-length or full-page WRITE bursts can be truncated with the BURST TERMINATE command. When
truncating a WRITE burst, the input data applied coincident with the BURST TERMINATE command will be
ignored. The last data written (provided that DQM is
LOW at that time) will be the input data applied one
clock previous to the BURST TERMINATE command.
This is shown in Figure 19, where data n is the last
desired data element of a longer burst.
Figure 19
Terminating a WRITE Burst
T0
T1
T2
CLK
BURST
TERMINATE
NEXT
COMMAND
COMMAND
WRITE
ADDRESS
BANK,
COL n
(ADDRESS)
DIN
n
(DATA)
DQ
TRANSITIONING DATA
POWER-DOWN
Power-down occurs if CKE is registered LOW coincident with a NOP or COMMAND INHIBIT when no accesses are in progress. If power-down occurs when all
banks are idle, this mode is referred to as precharge
power-down; if power-down occurs when there is a row
active in any bank, this mode is referred to as active
power-down. Entering power-down deactivates the input and output buffers, excluding CKE, for maximum
power savings while in standby. The device may not
remain in the power-down state longer than the refresh period (64ms) since no refresh operations are
performed in this mode.
The power-down state is exited by registering a NOP
or COMMAND INHIBIT and CKE HIGH at the desired
clock edge (meeting tCKS). See Figure 21.
DON’T CARE
NOTE: DQMs are LOW.
Figure 20
PRECHARGE Command
Figure 21
Power-Down
CLK
CKE
HIGH
((
))
((
))
CLK
CS#
tCKS
CKE
> tCKS
((
))
RAS#
COMMAND
((
))
((
))
NOP
NOP
All banks idle
CAS#
Input buffers gated off
Enter power-down mode.
Exit power-down mode.
ACTIVE
tRCD
tRAS
tRC
WE#
DON’T CARE
A0-A9
All Banks
A10
Bank Selected
BA0,1
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
BANK
ADDRESS
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64Mb: x4, x8, x16
SDRAM
CLOCK SUSPEND
The clock suspend mode occurs when a column access/burst is in progress and CKE is registered LOW. In
the clock suspend mode, the internal clock is deactivated, “freezing” the synchronous logic.
For each positive clock edge on which CKE is
sampled LOW, the next internal positive clock edge is
suspended. Any command or data present on the input pins at the time of a suspended internal clock edge
is ignored; any data present on the DQ pins remains
driven; and burst counters are not incremented, as
long as the clock is suspended. (See examples in
Figures 22 and 23.)
Clock suspend mode is exited by registering CKE
HIGH; the internal clock and related operation will resume on the subsequent positive clock edge.
BURST READ/SINGLE WRITE
The burst read/single write mode is entered by programming the write burst mode bit (M9) in the mode
register to a logic 1. In this mode, all WRITE commands
result in the access of a single column location (burst of
one), regardless of the programmed burst length. READ
commands access columns according to the programmed burst length and sequence, just as in the
normal mode of operation (M9 = 0).
Figure 22
Clock Suspend During WRITE Burst
T0
T1
T2
T3
T4
Figure 23
Clock Suspend During READ Burst
T5
T0
CLK
CKE
T2
T3
T4
T5
T6
CKE
INTERNAL
CLOCK
COMMAND
T1
CLK
INTERNAL
CLOCK
NOP
ADDRESS
DIN
WRITE
NOP
NOP
BANK,
COL n
DIN
n
TRANSITIONING DATA
DIN
n+1
DIN
n+2
COMMAND
READ
ADDRESS
BANK,
COL n
DQ
NOP
NOP
DOUT
n
NOP
DOUT
n+1
NOP
DOUT
n+2
NOP
DOUT
n+3
DON’T CARE
TRANSITIONING DATA
DON’T CARE
NOTE: For this example, CAS latency = 2, burst length = 4 or greater, and
DQM is LOW.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
CONCURRENT AUTO PRECHARGE
An access command (READ or WRITE) to another
bank while an access command with auto precharge
enabled is executing is not allowed by SDRAMs, unless
the SDRAM supports CONCURRENT AUTO
PRECHARGE. Micron SDRAMs support CONCURRENT
AUTO PRECHARGE. Four cases where CONCURRENT
AUTO PRECHARGE occurs are defined below.
on bank n, CAS latency later. The PRECHARGE to
bank n will begin when the READ to bank m is registered (Figure 24).
2. Interrupted by a WRITE (with or without auto
precharge): A WRITE to bank m will interrupt a READ
on bank n when registered. DQM should be used
two clocks prior to the WRITE command to prevent
bus contention. The PRECHARGE to bank n will
begin when the WRITE to bank m is registered
(Figure 25).
READ with Auto Precharge
1. Interrupted by a READ (with or without auto
precharge): A READ to bank m will interrupt a READ
Figure 24
READ With Auto Precharge Interrupted by a READ
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
BANK n
Internal
States
READ - AP
BANK n
NOP
Page Active
READ - AP
BANK m
NOP
READ with Burst of 4
NOP
NOP
NOP
Idle
Interrupt Burst, Precharge
tRP - BANK m
t RP - BANK n
Page Active
BANK m
Precharge
READ with Burst of 4
BANK n,
COL a
ADDRESS
NOP
BANK m,
COL d
DOUT
a+1
DOUT
a
DQ
DOUT
d
DOUT
d+1
CAS Latency = 3 (BANK n)
CAS Latency = 3 (BANK m)
NOTE: DQM is LOW.
TRANSITIONING DATA
DON’T CARE
Figure 25
READ With Auto Precharge Interrupted by a WRITE
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
BANK n
Internal
States
READ - AP
BANK n
Page
Active
NOP
NOP
NOP
READ with Burst of 4
WRITE - AP
BANK m
NOP
NOP
Interrupt Burst, Precharge
Idle
tRP - BANK n
Page Active
BANK m
ADDRESS
NOP
Write-Back
WRITE with Burst of 4
BANK n,
COL a
t WR - BANK m
BANK m,
COL d
1
DQM
DOUT
a
DQ
CAS Latency = 3 (BANK n)
DIN
d
DIN
d+1
DIN
d+2
TRANSITIONING DATA
DIN
d+3
DON’T CARE
NOTE: 1. DQM is HIGH at T2 to prevent DOUT-a+1 from contending with DIN-d at T4.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
WRITE with Auto Precharge
3. Interrupted by a READ (with or without auto
precharge): A READ to bank m will interrupt a WRITE
on bank n when registered, with the data-out appearing CAS latency later. The PRECHARGE to bank n will
begin after tWR is met, where tWR begins when the
READ to bank m is registered. The last valid WRITE to
bank n will be data-in registered one clock prior to the
READ to bank m (Figure 26).
4. Interrupted by a WRITE (with or without auto
precharge): A WRITE to bank m will interrupt a WRITE
on bank n when registered. The PRECHARGE to bank
n will begin after tWR is met, where tWR begins when
the WRITE to bank m is registered. The last valid data
WRITE to bank n will be data registered one clock prior
to a WRITE to bank m (Figure 27).
Figure 26
WRITE With Auto Precharge Interrupted by a READ
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
BANK n
Internal
States
NOP
WRITE - AP
BANK n
Page Active
READ - AP
BANK m
NOP
WRITE with Burst of 4
DIN
a
DQ
NOP
Precharge
tWR - BANK n
tRP - BANK n
NOP
tRP - BANK m
READ with Burst of 4
BANK n,
COL a
ADDRESS
NOP
Interrupt Burst, Write-Back
Page Active
BANK m
NOP
BANK m,
COL d
DOUT
d+1
DOUT
d
DIN
a+1
CAS Latency = 3 (BANK m)
TRANSITIONING DATA
NOTE: 1. DQM is LOW.
DON’T CARE
Figure 27
WRITE With Auto Precharge Interrupted by a WRITE
T0
T1
T2
T3
T4
T5
T6
T7
CLK
COMMAND
BANK n
Internal
States
NOP
WRITE - AP
BANK n
Page Active
NOP
NOP
WRITE with Burst of 4
WRITE - AP
BANK m
NOP
NOP
Interrupt Burst, Write-Back
Precharge
tRP - BANK n
tWR - BANK n
BANK m
ADDRESS
DQ
Page Active
DIN
a
t WR - BANK m
Write-Back
WRITE with Burst of 4
BANK n,
COL a
NOP
BANK m,
COL d
DIN
a+1
DIN
a+2
DIN
d
DIN
d+1
DIN
d+2
TRANSITIONING DATA
DIN
d+3
DON’T CARE
NOTE: 1. DQM is LOW.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
TRUTH TABLE 2 – CKE
(Notes: 1-4)
CKEn-1 CKEn
L
L
L
H
H
L
CURRENT STATE
COMMANDn
Power-Down
X
Self Refresh
X
Maintain Self Refresh
Clock Suspend
X
Maintain Clock Suspend
Power-Down
COMMAND INHIBIT or NOP
Exit Power-Down
5
Self Refresh
COMMAND INHIBIT or NOP
Exit Self Refresh
6
Clock Suspend
X
Exit Clock Suspend
7
All Banks Idle
COMMAND INHIBIT or NOP
Power-Down Entry
All Banks Idle
AUTO REFRESH
Self Refresh Entry
Reading or Writing
H
H
VALID
ACTIONn
NOTES
Maintain Power-Down
Clock Suspend Entry
See Truth Table 3
NOTE: 1.
2.
3.
4.
5.
CKEn is the logic state of CKE at clock edge n; CKE n-1 was the state of CKE at the previous clock edge.
Current state is the state of the SDRAM immediately prior to clock edge n.
COMMANDn is the command registered at clock edge n, and ACTIONn is a result of COMMANDn.
All states and sequences not shown are illegal or reserved.
Exiting power-down at clock edge n will put the device in the all banks idle state in time for clock edge n + 1 (provided
that tCKS is met).
6. Exiting self refresh at clock edge n will put the device in the all banks idle state once tXSR is met. COMMAND INHIBIT
or NOP commands should be issued on any clock edges occurring during the tXSR period. A minimum of two NOP
commands must be provided during tXSR period.
7. After exiting clock suspend at clock edge n, the device will resume operation and recognize the next command at clock
edge n + 1.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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64Mb: x4, x8, x16
SDRAM
TRUTH TABLE 3 – CURRENT STATE BANK n, COMMAND TO BANK n
(Notes: 1-6; notes appear below and on next page)
CURRENT STATE CS# RAS#CAS# WE#
Any
Idle
Row Active
COMMAND (ACTION)
NOTES
H
X
X
X
COMMAND INHIBIT (NOP/Continue previous operation)
L
H
H
H
NO OPERATION (NOP/Continue previous operation)
L
L
H
H
ACTIVE (Select and activate row)
L
L
L
H
AUTO REFRESH
7
L
L
L
L
LOAD MODE REGISTER
7
L
L
H
L
PRECHARGE
11
L
H
L
H
READ (Select column and start READ burst)
10
L
H
L
L
WRITE (Select column and start WRITE burst)
10
L
L
H
L
PRECHARGE (Deactivate row in bank or banks)
8
Read
L
H
L
H
READ (Select column and start new READ burst)
10
(Auto
L
H
L
L
WRITE (Select column and start WRITE burst)
10
Precharge
L
L
H
L
PRECHARGE (Truncate READ burst, start PRECHARGE)
8
Disabled)
L
H
H
L
BURST TERMINATE
9
Write
L
H
L
H
READ (Select column and start READ burst)
10
(Auto
L
H
L
L
WRITE (Select column and start new WRITE burst)
10
Precharge
L
L
H
L
PRECHARGE (Truncate WRITE burst, start PRECHARGE)
8
Disabled)
L
H
H
L
BURST TERMINATE
9
NOTE: 1. This table applies when CKE n-1 was HIGH and CKEn is HIGH (see Truth Table 2) and after tXSR has been
met (if the previous state was self refresh).
2. This table is bank-specific, except where noted; i.e., the current state is for a specific bank and the commands shown
are those allowed to be issued to that bank when in that state. Exceptions are covered in the notes below.
3. Current state definitions:
Idle: The bank has been precharged, and tRP has been met.
Row Active: A row in the bank has been activated, and tRCD has been met. No data bursts/accesses and
no register accesses are in progress.
Read: A READ burst has been initiated, with auto precharge disabled, and has not yet terminated
or been terminated.
Write: A WRITE burst has been initiated, with auto precharge disabled, and has not yet terminated or been terminated.
4. The following states must not be interrupted by a command issued to the same bank. COMMAND INHIBIT or NOP
commands, or allowable commands to the other bank should be issued on any clock edge occurring during these states.
Allowable commands to the other bank are determined by its current state and Truth Table 3, and according to Truth
Table 4.
Precharging: Starts with registration of a PRECHARGE command and ends when tRP is met. Once tRP is
met, the bank will be in the idle state.
Row Activating: Starts with registration of an ACTIVE command and ends when tRCD is met. Once tRCD is
met, the bank will be in the row active state.
Read w/Auto
Precharge Enabled: Starts with registration of a READ command with auto precharge enabled and ends when
tRP has been met. Once tRP is met, the bank will be in the idle state.
Write w/Auto
Precharge Enabled: Starts with registration of a WRITE command with auto precharge enabled and ends when
tRP has been met. Once tRP is met, the bank will be in the idle state.
(Continued on next page)
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
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©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
NOTE (continued):
5. The following states must not be interrupted by any executable command; COMMAND INHIBIT or NOP commands must
be applied on each positive clock edge during these states.
Refreshing: Starts with registration of an AUTO REFRESH command and ends when tRC is met. Once tRC
is met, the SDRAM will be in the all banks idle state.
Accessing Mode
Register: Starts with registration of a LOAD MODE REGISTER command and ends when tMRD has
been met. Once tMRD is met, the SDRAM will be in the all banks idle state.
Precharging All: Starts with registration of a PRECHARGE ALL command and ends when tRP is met. Once tRP
is met, all banks will be in the idle state.
6. All states and sequences not shown are illegal or reserved.
7. Not bank-specific; requires that all banks are idle.
8. May or may not be bank-specific; if all banks are to be precharged, all must be in a valid state for precharging.
9. Not bank-specific; BURST TERMINATE affects the most recent READ or WRITE burst, regardless of bank.
10. READs or WRITEs listed in the Command (Action) column include READs or WRITEs with auto precharge enabled and
READs or WRITEs with auto precharge disabled.
11. Does not affect the state of the bank and acts as a NOP to that bank.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
29
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
TRUTH TABLE 4 – CURRENT STATE BANK n, COMMAND TO BANK m
(Notes: 1-6; notes appear below and on next page)
CURRENT STATE CS# RAS# CAS# WE#
COMMAND (ACTION)
NOTES
Any
H
X
X
X
COMMAND INHIBIT (NOP/Continue previous operation)
L
H
H
H
NO OPERATION (NOP/Continue previous operation)
Idle
X
X
X
X
Any Command Otherwise Allowed to Bank m
ACTIVE (Select and activate row)
Row
L
L
H
H
Activating,
L
H
L
H
READ (Select column and start READ burst)
7
Active, or
L
H
L
L
WRITE (Select column and start WRITE burst)
7
Precharging
L
L
H
L
PRECHARGE
Read
L
L
H
H
ACTIVE (Select and activate row)
(Auto
L
H
L
H
READ (Select column and start new READ burst)
7, 10
Precharge
L
H
L
L
WRITE (Select column and start WRITE burst)
7, 11
Disabled)
L
L
H
L
PRECHARGE
Write
L
L
H
H
ACTIVE (Select and activate row)
9
(Auto
L
H
L
H
READ (Select column and start READ burst)
7, 12
Precharge
L
H
L
L
WRITE (Select column and start new WRITE burst)
7, 13
Disabled)
L
L
H
L
PRECHARGE
Read
L
L
H
H
ACTIVE (Select and activate row)
(With Auto
L
H
L
H
READ (Select column and start new READ burst)
7, 8, 14
Precharge)
L
H
L
L
WRITE (Select column and start WRITE burst)
7, 8, 15
9
L
L
H
L
PRECHARGE
Write
L
L
H
H
ACTIVE (Select and activate row)
9
(With Auto
L
H
L
H
READ (Select column and start READ burst)
7, 8, 16
Precharge)
L
H
L
L
WRITE (Select column and start new WRITE burst)
7, 8, 17
L
L
H
L
PRECHARGE
9
NOTE: 1. This table applies when CKEn-1 was HIGH and CKEn is HIGH (see Truth Table 2) and after tXSR has been met (if the
previous state was self refresh).
2. This table describes alternate bank operation, except where noted; i.e., the current state is for bank n and the
commands shown are those allowed to be issued to bank m (assuming that bank m is in such a state that the given
command is allowable). Exceptions are covered in the notes below.
3. Current state definitions:
Idle: The bank has been precharged, and tRP has been met.
Row Active: A row in the bank has been activated, and tRCD has been met. No data bursts/accesses and
no register accesses are in progress.
Read: A READ burst has been initiated, with auto precharge disabled, and has not yet terminated
or been terminated.
Write: A WRITE burst has been initiated, with auto precharge disabled, and has not yet
terminated or been terminated.
Read w/Auto
Precharge Enabled: Starts with registration of a READ command with auto precharge enabled, and ends when
tRP has been met. Once tRP is met, the bank will be in the idle state.
Write w/Auto
Precharge Enabled: Starts with registration of a WRITE command with auto precharge enabled, and ends when
tRP has been met. Once tRP is met, the bank will be in the idle state.
(Continued on next page)
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
30
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
NOTE (continued):
4. AUTO REFRESH, SELF REFRESH and LOAD MODE REGISTER commands may only be issued when all banks are idle.
5. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state
only.
6. All states and sequences not shown are illegal or reserved.
7. READs or WRITEs to bank m listed in the Command (Action) column include READs or WRITEs with auto precharge
enabled and READs or WRITEs with auto precharge disabled.
8. CONCURRENT AUTO PRECHARGE: Bank n will initiate the auto precharge command when its burst has been interrupted
by bank m’s burst.
9. Burst in bank n continues as initiated.
10. For a READ without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will
interrupt the READ on bank n, CAS latency later (Figure 7).
11. For a READ without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will
interrupt the READ on bank n when registered (Figures 9 and 10). DQM should be used one clock prior to the WRITE
command to prevent bus contention.
12. For a WRITE without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will
interrupt the WRITE on bank n when registered (Figure 17), with the data-out appearing CAS latency later. The last
valid WRITE to bank n will be data-in registered one clock prior to the READ to bank m.
13. For a WRITE without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m
will interrupt the WRITE on bank n when registered (Figure 15). The last valid WRITE to bank n will be data-in
registered one clock prior to the READ to bank m.
14. For a READ with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will
interrupt the READ on bank n, CAS latency later. The PRECHARGE to bank n will begin when the READ to bank m is
registered (Figure 24).
15. For a READ with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will
interrupt the READ on bank n when registered. DQM should be used two clocks prior to the WRITE command to prevent
bus contention. The PRECHARGE to bank n will begin when the WRITE to bank m is registered (Figure 25).
16. For a WRITE with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will
interrupt the WRITE on bank n when registered, with the data-out appearing CAS latency later. The PRECHARGE to bank
n will begin after tWR is met, where tWR begins when the READ to bank m is registered. The last valid WRITE to bank n
will be data-in registered one clock prior to the READ to bank m (Figure 26).
17. For a WRITE with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will
interrupt the WRITE on bank n when registered. The PRECHARGE to bank n will begin after tWR is met, where tWR
begins when the WRITE to bank m is registered. The last valid WRITE to bank n will be data registered one clock prior
to the WRITE to bank m (Figure 27).
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
31
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
*Stresses greater than those listed under “Absolute
Maximum Ratings” may cause permanent damage to
the device. This is a stress rating only, and functional
operation of the device at these or any other conditions
above those indicated in the operational sections of
this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may
affect reliability.
ABSOLUTE MAXIMUM RATINGS*
Voltage on VDD, VDDQ Supply
Relative to VSS ............................................ -1V to +4.6V
Voltage on Inputs, NC or I/O Pins
Relative to VSS ............................................ -1V to +4.6V
Operating Temperature,
TA (commercial) ...................................... 0°C to +70°C
Operating Temperature,
TA (extended; IT parts) ...................... -40°C to +85°C
Storage Temperature (plastic) ............ -55°C to +150°C
Power Dissipation ........................................................ 1W
DC ELECTRICAL CHARACTERISTICS AND OPERATING CONDITIONS
(Notes: 1, 5, 6; notes appear on page 35); VDD, VDDQ = +3.3V ±0.3V
PARAMETER/CONDITION
SYMBOL
MIN
MAX
Supply Voltage
VDD, VDDQ
3
3.6
V
Input High Voltage: Logic 1; All inputs
VIH
2
VDD + 0.3
V
22
Input Low Voltage: Logic 0; All inputs
VIL
-0.3
0.8
V
22
II
-5
5
µA
Input Leakage Current:
Any input 0V ≤ VIN ≤ VDD
(All other pins not under test = 0V)
UNITS NOTES
Output Leakage Current: DQs are disabled; 0V ≤ VOUT ≤ VDDQ
IOZ
-5
5
µA
Output Levels:
Output High Voltage (IOUT = -4mA)
Output Low Voltage (IOUT = 4mA)
VOH
2.4
–
V
VOL
–
0.4
V
IDD SPECIFICATIONS AND CONDITIONS
(Notes: 1, 5, 6, 11, 13; notes appear on page 35) ; VDD, VDDQ = +3.3V ±0.3V
MAX
PARAMETER/CONDITION
SYMBOL
-6
-7E
-75
-8E
Operating Current: Active Mode;
Burst = 2; READ or WRITE; tRC >= tRC (MIN)
IDD1
150
125
115
95
mA
3, 18,
19, 32
Standby Current: Power-Down Mode; All banks idle;
CKE = LOW
IDD2
2
2
2
2
mA
32
Standby Current: Active Mode;
CKE = HIGH; CS# = HIGH; All banks active after tRCD met;
No accesses in progress
IDD3
60
45
45
35
mA
3, 12,
19, 32
Operating Current: Burst Mode; Page burst;
READ or WRITE; All banks active
IDD4
180
150
140
120
mA
3, 18,
19, 32
mA
3, 12,
18, 19,
32, 33
mA
4
Auto Refresh Current:
CKE = HIGH; CS# = HIGH
tRFC
= tRFC (MIN)
IDD5
250
230
210
190
tRFC
= 15.625µs
IDD6
3
3
3
3
IDD7
1
1
1
1
0.5
0.5
0.5
0.5
Self Refresh Current:
Standard
CKE ≤ 0.2V
Low power (L)
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
32
UNITS NOTES
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
CAPACITANCE
(Note: 2; notes appear on page 35)
PARAMETER
SYMBOL
MIN
Input Capacitance: CLK
CI1
2.5
MAX UNITS NOTES
3.5
pF
29
Input Capacitance: All other input-only pins
CI2
2.5
3.8
pF
30
Input/Output Capacitance: DQs
CIO
4.0
6.0
pF
31
ELECTRICAL CHARACTERISTICS AND RECOMMENDED AC OPERATING CONDITIONS
(Notes: 5, 6, 8, 9, 11; notes appear on page 35); VDD, VDDQ = +3.3V ±0.3V
AC CHARACTERISTICS
PARAMETER
Access time from CLK (pos. edge)
Address hold time
Address setup time
CLK high-level width
CLK low-level width
Clock cycle time
CL = 3
CL = 2
CL = 3
CL = 2
CKE hold time
CKE setup time
CS#, RAS#, CAS#, WE#, DQM hold time
CS#, RAS#, CAS#, WE#, DQM setup time
Data-in hold time
Data-in setup time
Data-out high-impedance time
CL = 3
CL = 2
Data-out low-impedance time
Data-out hold time (load)
Data-out hold time (no load)
ACTIVE to PRECHARGE command
ACTIVE to ACTIVE command period
ACTIVE to READ or WRITE delay
Refresh period (4,096 rows)
AUTO REFRESH period
PRECHARGE command period
ACTIVE bank a to ACTIVE bank b command
Transition time
WRITE recovery time
Exit SELF REFRESH to ACTIVE command
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
-6
-7E
-75
-8E
SYMBOL MIN
MAX
MIN
MAX MIN
MAX
MIN
MAX UNITS NOTES
tAC(3)
5.5
5.4
5.4
6
ns
27
tAC(2)
–
5.4
6
6
ns
tAH
1
0.8
0.8
1
ns
tAS
1.5
1.5
1.5
2
ns
tCH
2.5
2.5
2.5
3
ns
tCL
2.5
2.5
2.5
3
ns
tCK(3)
6
7
7.5
8
ns
23
tCK(2)
–
7.5
10
10
ns
23
tCKH
1
0.8
0.8
1
ns
tCKS
1.5
1.5
1.5
2
ns
tCMH
1
0.8
0.8
1
ns
tCMS
1.5
1.5
1.5
2
ns
tDH
1
0.8
0.8
1
ns
tDS
1.5
1.5
1.5
2
ns
tHZ(3)
5.5
5.4
5.4
6
ns
10
tHZ(2)
–
5.4
6
6
ns
10
tLZ
1
1
1
1
ns
tOH
2
3
3
3
ns
tOH
1.8
1.8
1.8
1.8
ns
28
N
tRAS
42 120,000 37 120,000 44 120,000 50 120,000 ns
tRC
60
60
66
70
ns
tRCD
18
15
20
20
ns
tREF
64
64
64
64
ms
tRFC
60
66
66
70
ns
tRP
18
15
20
20
ns
tRRD
12
14
15
20
ns
tT
0.3
1.2
0.3
1.2
0.3
1.2
0.3
1.2
ns
7
tWR
1 CLK +
1 CLK +
1 CLK +
1 CLK +
–
24
6ns
7ns
7.5ns
7ns
12
14
15
15
ns
25
tXSR
70
67
75
80
ns
20
33
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
AC FUNCTIONAL CHARACTERISTICS
(Notes: 5, 6, 7, 8, 9, 11; notes appear on page 35) VDD, VDDQ = +3.3V ±0.3V
PARAMETER
READ/WRITE command to READ/WRITE command
CKE to clock disable or power-down entry mode
CKE to clock enable or power-down exit setup mode
DQM to input data delay
DQM to data mask during WRITEs
DQM to data high-impedance during READs
WRITE command to input data delay
Data-in to ACTIVE command
Data-in to PRECHARGE command
Last data-in to burst STOP command
Last data-in to new READ/WRITE command
Last data-in to PRECHARGE command
LOAD MODE REGISTER command to ACTIVE or REFRESH command
Data-out to high-impedance from PRECHARGE command
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
34
SYMBOL
tCCD
tCKED
tPED
tDQD
tDQM
tDQZ
tDWD
tDAL
tDPL
tBDL
tCDL
tRDL
tMRD
CL = 3 tROH(3)
CL = 2 tROH(2)
-6
1
1
1
0
0
2
0
5
2
1
1
2
2
3
2
-7E
1
1
1
0
0
2
0
4
2
1
1
2
2
3
2
-75
1
1
1
0
0
2
0
5
2
1
1
2
2
3
2
-8E
1
1
1
0
0
2
0
4
2
1
1
2
2
3
2
UNITS
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
tCK
NOTES
17
14
14
17
17
17
17
15, 21
16, 21
17
17
16, 21
26
17
17
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
NOTES
1.
2.
3.
4.
5.
6.
7.
8.
9.
All voltages referenced to VSS.
This parameter is sampled. VDD, V DDQ = +3.3V;
f = 1 MHz, TA = 25°C; pin under test biased at 1.4V.
IDD is dependent on output loading and cycle rates.
Specified values are obtained with minimum cycle
time and the outputs open.
Enables on-chip refresh and address counters.
The minimum specifications are used only to
indicate cycle time at which proper operation over
the full temperature range (0°C ≤ TA ≤ +70°C and
-40°C ≤ TA ≤ +85°C for IT parts) is ensured.
An initial pause of 100µs is required after powerup, followed by two AUTO REFRESH commands,
before proper device operation is ensured. (VDD
and VDDQ must be powered up simultaneously. VSS
and VSSQ must be at same potential.) The two
AUTO REFRESH command wake-ups should be
repeated any time the tREF refresh requirement is
exceeded.
AC characteristics assume tT = 1ns.
In addition to meeting the transition rate specification, the clock and CKE must transit between VIH
and VIL (or between VIL and VIH) in a monotonic
manner.
Outputs measured at 1.5V with equivalent load:
13. IDD specifications are tested after the device is properly initialized.
14. Timing actually specified by tCKS; clock(s) specified as a reference only at minimum cycle rate.
15. Timing actually specified by tWR plus tRP; clock(s)
specified as a reference only at minimum cycle rate.
16. Timing actually specified by tWR.
17. Required clocks are specified by JEDEC functionality and are not dependent on any timing parameter.
18. The IDD current will increase or decrease proportionally according to the amount of frequency alteration for the test condition.
19. Address transitions average one transition every
two clocks.
20. CLK must be toggled a minimum of two times during this period.
21. Based on tCK = 10ns for -8E , tCK=7.5ns for -75
and -7E, tCK = 6ns for -6.
22. VIH overshoot: VIH (MAX) = VDDQ + 2V for a pulse
width ≤ 3ns, and the pulse width cannot be greater
than one third of the cycle rate. VIL undershoot: VIL
(MIN) = -2V for a pulse width ≤ 3ns.
23. The clock frequency must remain constant (stable
clock is defined as a signal cycling within timing
constraints specified for the clock pin) during access or precharge states (READ, WRITE, including
tWR, and PRECHARGE commands). CKE may be
used to reduce the data rate.
24. Auto precharge mode only. The precharge timing
budget (tRP) begins 6ns/7ns/7.5ns/7ns after the
first clock delay, after the last WRITE is executed.
25. Precharge mode only.
26. JEDEC and PC100 specify three clocks.
27. tAC for -75/-7E at CL = 3 with no load is 4.6ns and is
guaranteed by design.
28. Parameter guaranteed by design.
29. PC100 specifies a maximum of 4pF.
30. PC100 specifies a maximum of 5pF.
31. PC100 specifies a maximum of 6.5pF.
32. For -8E, CL = 2 and tCK = 10ns; for -75, CL = 3 and
tCK = 7.5ns; for -7E, CL = 2 and tCK = 7.5ns; for -6,
CL = 3 and tCK = 6ns.
33. CKE is HIGH during refresh command period
tRFC (MIN) else CKE is LOW. The IDD6 limit is actually a nominal value and does not result in a fail
value.
Q
50pF
10. tHZ defines the time at which the output achieves
the open circuit condition; it is not a reference to
VOH or VOL. The last valid data element will meet
tOH before going High-Z.
11. AC timing and IDD tests have VIL = 0V and VIH = 3V,
with timing referenced to 1.5V crossover point. If
the input transition time is longer than 1 ns, then
the timing is referenced at VIL (MAX) and VIH (MIN)
and no longer at the 1.5V crossover point. CLK
should always be 1.5V referenced to crossover. Refer to Micron Technical Note TN-48-09
12. Other input signals are allowed to transition no
more than once every two clocks and are otherwise
at valid VIH or VIL levels.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
35
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
1
INITIALIZE AND LOAD MODE REGISTER
T0
CLK
((
))
CKE
((
))
((
))
COMMAND
((
))
((
))
tCK
T1
tCKH
tCKS
Tn + 1
((
))
((
))
((
))
((
))
tCH
NOP
tCMS tCMH
((
))
((
))
((
))
((
))
((
))
tCMS tCMH
To + 1
tCL
((
))
NOP
NOP
((
))
AUTO
REFRESH
((
))
NOP
NOP
((
))
AUTO
REFRESH
((
))
((
))
((
))
((
))
((
))
((
))
A0-A9, A11
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
A10
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
BA0, BA1
((
))
((
))
DQ
((
))
SINGLE BANK
ALL
BANKS
High-Z
T = 100µs
MIN
Power-up:
VDD and
CLK stable
Tp + 3
tCMS tCMH
((
))
PRECHARGE
((
))
ALL BANKS
Tp + 2
((
))
((
))
((
))
DQM /
DQML, DQMH
Tp + 1
LOAD MODE
REGISTER
tAS
NOP
ACTIVE
tAH
ROW
CODE
tAS
tAH
ROW
CODE
BANK
((
))
tRP
Precharge
all banks
tRFC
tRFC
tMRD
Program Mode Register 2, 3, 4
AUTO REFRESH
AUTO REFRESH
DON’T CARE
TIMING PARAMETERS
SYMBOL*
tAH
tAS
tCH
tCL
tCK(3)
tCK(2)
tCKH
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
2.5
2.5
2.5
3
ns
2.5
2.5
2.5
3
ns
6
7
7.5
8
ns
–
7.5
10
10
ns
1
0.8
0.8
1
ns
SYMBOL*
tCKS
tCMH
tCMS
tMRD3
tRFC
tRP
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1.5
1
1.5
2
60
18
1.5
0.8
1.5
2
66
15
1.5
0.8
1.5
2
66
20
2
1
2
2
70
20
ns
ns
ns
tCK
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1.
2.
3.
4.
If CS# is HIGH at clock HIGH time, all commands applied are NOP.
The mode register may be loaded prior to the AUTO REFRESH cycles if desired.
JEDEC and PC100 specify three clocks.
Outputs are guaranteed High-Z after command is issued.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
36
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
POWER-DOWN MODE
T0
T1
tCK
CLK
T2
tCH
CKE
tCKS
PRECHARGE
Tn + 2
tCKS
((
))
tCKH
tCMS tCMH
COMMAND
Tn + 1
((
))
((
))
tCL
tCKS
1
NOP
((
))
((
))
NOP
NOP
ACTIVE
DQM /
DQML, DQMH
((
))
((
))
A0-A9, A11
((
))
((
))
ROW
((
))
((
))
ROW
((
))
((
))
BANK
ALL BANKS
A10
SINGLE BANK
tAS
BA0, BA1
tAH
BANK(S)
High-Z
((
))
DQ
Two clock cycles
Input buffers gated off while in
power-down mode
Precharge all
active banks
All banks idle, enter
power-down mode
All banks idle
Exit power-down mode
DON’T CARE
TIMING PARAMETERS
SYMBOL*
tAH
tAS
tCH
tCL
tCK(3)
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
2.5
2.5
2.5
3
ns
2.5
2.5
2.5
3
ns
6
7
7.5
8
ns
SYMBOL*
tCK(2)
tCKH
tCKS
tCMH
tCMS
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
–
7.5
10
10
ns
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
*CAS latency indicated in parentheses.
NOTE: 1. Violating refresh requirements during power-down may result in a loss of data.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
37
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
CLOCK SUSPEND MODE
T0
T1
tCK
CLK
T2
T3
T4
T5
1
T6
T7
T8
NOP
WRITE
T9
tCL
tCH
tCKS tCKH
CKE
tCKS
tCKH
tCMS tCMH
COMMAND
READ
NOP
NOP
NOP
NOP
NOP
tCMS tCMH
DQM /
DQML, DQMH
A0-A9, A11
tAS
tAH
COLUMN m 2
tAS
COLUMN e 2
tAH
A10
tAS
BA0, BA1
tAH
BANK
BANK
tAC
tOH
tAC
DQ
tLZ
DOUT m
tHZ
DOUT m + 1
tDS
tDH
DIN e
DIN e + 1
DON’T CARE
UNDEFINED
TIMING PARAMETERS
SYMBOL*
tAC(3)
tAC(2)
tAH
tAS
tCH
tCL
tCK(3)
tCK(2)
tCKH
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
5.5
5.4
5.4
6
ns
–
5.4
6
6
ns
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
2.5
2.5
2.5
3
ns
2.5
2.5
2.5
3
ns
6
7
7.5
8
ns
–
7.5
10
10
ns
1
0.8
0.8
1
ns
SYMBOL*
tCKS
tCMH
tCMS
tDH
tDS
tHZ(3)
tHZ(2)
tLZ
tOH
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1.5
1.5
1.5
2
ns
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
5.5
5.4
5.4
6
ns
–
5.4
6
7
ns
1
1
1
1
ns
2
3
3
3
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 2, the CAS latency = 3, and auto precharge is disabled.
2. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
38
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
AUTO REFRESH MODE
T0
CLK
T1
tCK
T2
tCH
tCKS
tCKH
tCMS
tCMH
PRECHARGE
NOP
AUTO
REFRESH
NOP
A0-A9, A11
ALL BANKS
A10
SINGLE BANK
tAS
BA0, BA1
DQ
((
))
((
))
( ( NOP
))
AUTO
REFRESH
NOP
((
))
((
))
DQM /
DQML, DQMH
To + 1
((
))
((
))
tCL
((
))
CKE
COMMAND
Tn + 1
((
))
((
))
((
))
( ( NOP
))
ACTIVE
((
))
((
))
((
))
((
))
((
))
((
))
ROW
((
))
((
))
((
))
((
))
ROW
tAH
BANK(S)
High-Z
tRP
((
))
((
))
((
))
((
))
((
))
((
))
tRFC1
BANK
tRFC1
Precharge all
active banks
DON’T CARE
TIMING PARAMETERS
SYMBOL*
tAH
tAS
tCH
tCL
tCK(3)
tCK(2)
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
2.5
2.5
2.5
3
ns
2.5
2.5
2.5
3
ns
6
7
7.5
8
ns
–
7.5
10
10
ns
SYMBOL*
tCKH
tCKS
tCMH
tCMS
tRFC
tRP
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1
1.5
1
1.5
0.8
1.5
0.8
1.5
0.8
1.5
0.8
1.5
1
2
1
2
ns
ns
ns
ns
60
18
66
15
66
20
70
20
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1. Each AUTO REFRESH command performs a refresh cycle. Back-to-back commands are not required.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
39
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
SELF REFRESH MODE
T0
CLK
T1
tCK
tCL
tCH
T2
tCKS
COMMAND
tCKH
tCMS
tCMH
PRECHARGE
((
))
((
))
≥ tRAS(MIN)1
CKE
tCKS
Tn + 1
((
))
((
))
((
))
((
))
AUTO
REFRESH
((
) ) or COMMAND
NOP ( (
((
))
((
))
((
))
((
))
A0-A9, A11
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
ALL BANKS
SINGLE BANK
tAS
BA0, BA1
DQ
INHIBIT
AUTO
REFRESH
))
DQM/
DQML, DQMH
A10
To + 2
((
))
((
))
((
))
NOP
To + 1
tAH
BANK(S)
High-Z
((
))
((
))
tRP
Precharge all
active banks
tXSR2
Enter self refresh mode
Exit self refresh mode
(Restart refresh time base)
DON’T CARE
CLK stable prior to exiting
self refresh mode
TIMING PARAMETERS
-6
-7E
SYMBOL* MIN MAX MIN MAX
tAH
1
0.8
tAS
1.5
1.5
tCH
2.5
2.5
tCL
2.5
2.5
tCK(3)
6
7
tCK(2)
–
7.5
tCKH
1
0.8
-75
-8E
MIN MAX MIN MAX UNITS
0.8
1
ns
1.5
2
ns
2.5
3
ns
2.5
3
ns
7.5
8
ns
10
10
ns
0.8
1
ns
-6
SYMBOL* MIN MAX
tCKS
1.5
tCMH
1
tCMS
1.5
tRAS
42 120,000
tRP
18
tXSR
70
-7E
MIN MAX
1.5
0.8
1.5
37 120,000
15
67
-75
MIN MAX
1.5
0.8
1.5
44 120,000
20
75
-8E
MIN MAX UNITS
2
ns
1
ns
2
ns
50 120,000 ns
20
ns
80
ns
*CAS latency indicated in parentheses.
NOTES: 1. No maximum time limit for Self Refresh mode. tRAS(MAX) applies to non-Self Refresh mode.
2. tXSR requires minimum of two clocks regardless of frequency and timing.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
40
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
READ – WITHOUT AUTO PRECHARGE
T0
T1
tCK
CLK
T2
T3
T4
T5
NOP
NOP
1
T6
T7
T8
NOP
ACTIVE
tCL
tCH
tCKS
tCKH
CKE
tCMS tCMH
COMMAND
ACTIVE
NOP
READ
NOP
PRECHARGE
tCMS tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
tAS
COLUMN m2
ROW
tAH
ALL BANKS
ROW
A10
tAS
BA0, BA1
tAH
ROW
ROW
tAH
DISABLE AUTO PRECHARGE
SINGLE BANKS
BANK
BANK(S)
BANK
tAC
tOH
tAC
DQ
tLZ
tRCD
DOUT m
tAC
tOH
DOUT m+1
BANK
tAC
tOH
tOH
DOUT m+2
DOUT m+3
tHZ
tRP
CAS Latency
tRAS
tRC
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
-7E
SYMBOL* MIN MAX MIN MAX
tAC(3)
5.5
5.4
tAC(2)
–
5.4
tAH
1
0.8
tAS
1.5
1.5
tCH
2.5
2.5
tCL
2.5
2.5
tCK(3)
6
7
tCK(2)
–
7.5
tCKH
1
0.8
tCKS
1.5
1.5
-75
-8E
MIN MAX MIN MAX UNITS
5.4
6
ns
6
6
ns
0.8
1
ns
1.5
2
ns
2.5
3
ns
2.5
3
ns
7.5
8
ns
10
10
ns
0.8
1
ns
1.5
2
ns
-6
-7E
-75
-8E
SYMBOL* MIN MAX MIN MAX MIN MAX MIN MAX UNITS
tCMH
1
0.8
0.8
1
ns
tCMS
1.5
1.5
1.5
2
ns
tHZ(3)
5.5
5.4
5.4
6
ns
tHZ(2)
–
5.4
6
6
ns
tLZ
1
1
1
1
ns
tOH
2
3
3
3
ns
tRAS
42 120,000 37 120,000 44 120,000 50 120,000 ns
tRC
60
60
66
70
ns
tRCD
18
15
20
20
ns
tRP
18
15
20
20
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 4, the CAS latency = 2, and the READ burst is followed by a “manual” PRECHARGE.
2. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
41
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
READ – WITH AUTO PRECHARGE
T0
T1
tCK
CLK
tCKS
T2
T3
T4
T5
NOP
NOP
1
T6
T7
T8
NOP
ACTIVE
tCL
tCH
tCKH
CKE
tCMS tCMH
COMMAND
ACTIVE
NOP
READ
tCMS
NOP
NOP
tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
tAS
A10
COLUMN m 2
tAH
ROW
ENABLE AUTO PRECHARGE
ROW
tAS
BA0, BA1
tAH
ROW
ROW
tAH
BANK
BANK
BANK
tAC
tOH
tAC
DQ
tLZ
tRCD
DOUT m
tAC
tOH
DOUT m + 1
tAC
tOH
DOUT m + 2
tOH
DOUT m + 3
tHZ
tRP
CAS Latency
tRAS
tRC
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
-7E
SYMBOL* MIN MAX MIN MAX
tAC(3)
5.5
5.4
tAC(2)
–
5.4
tAH
1
0.8
tAS
1.5
1.5
tCH
2.5
2.5
tCL
2.5
2.5
tCK(3)
6
7
tCK(2)
–
7.5
tCKH
1
0.8
tCKS
1.5
1.5
-75
-8E
MIN MAX MIN MAX UNITS
5.4
6
ns
6
6
ns
0.8
1
ns
1.5
2
ns
2.5
3
ns
2.5
3
ns
7.5
8
ns
10
10
ns
0.8
1
ns
1.5
2
ns
-6
-7E
-75
-8E
SYMBOL* MIN MAX MIN MAX MIN MAX MIN MAX UNITS
tCMH
1
0.8
0.8
1
ns
tCMS
1.5
1.5
1.5
2
ns
tHZ(3)
5.5
5.4
5.4
6
ns
tHZ(2)
–
5.4
6
6
ns
tLZ
1
1
1
1
ns
tOH
2
3
3
3
ns
tRAS
42 120,000 37 120,000 44 120,000 50 120,000 ns
tRC
60
60
66
70
ns
tRCD
18
15
20
20
ns
tRP
18
15
20
20
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 4, and the CAS latency = 2.
2. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
42
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
SINGLE READ – WITHOUT AUTO PRECHARGE
T0
T1
tCK
CLK
T2
T3
T4
T5
NOP
NOP3
T6
1
T7
T8
tCL
tCH
tCKS
tCKH
CKE
tCMS tCMH
COMMAND
ACTIVE
NOP
READ
tCMS
PRECHARGE
NOP
ACTIVE
NOP
tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
tAS
COLUMN m2
ROW
tAH
ALL BANKS
ROW
A10
tAS
BA0, BA1
tAH
ROW
ROW
DISABLE AUTO PRECHARGE
tAH
SINGLE BANKS
BANK
BANK
BANK(S)
tOH
tAC
DQ
tLZ
tRCD
BANK
DOUT m
tHZ
tRP
CAS Latency
tRAS
tRC
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
-7E
SYMBOL* MIN MAX MIN MAX
tAC(3)
5.5
5.4
tAC(2)
–
5.4
tAH
1
0.8
tAS
1.5
1.5
tCH
2.5
2.5
tCL
2.5
2.5
tCK(3)
6
7
tCK(2)
–
7.5
tCKH
1
0.8
tCKS
1.5
1.5
-75
-8E
MIN MAX MIN MAX UNITS
5.4
6
ns
6
6
ns
0.8
1
ns
1.5
2
ns
2.5
3
ns
2.5
3
ns
7.5
8
ns
10
10
ns
0.8
1
ns
1.5
2
ns
-6
-7E
-75
-8E
SYMBOL* MIN MAX MIN MAX MIN MAX MIN MAX UNITS
tCMH
1
0.8
0.8
1
ns
tCMS
1.5
1.5
1.5
2
ns
tHZ(3)
5.5
5.4
5.4
6
ns
tHZ(2)
–
5.4
6
6
ns
tLZ
1
1
1
1
ns
tOH
2
3
3
3
ns
tRAS
42 120,000 37 120,000 44 120,000 50 120,000 ns
tRC
60
60
66
70
ns
tRCD
18
15
20
20
ns
tRP
18
15
20
20
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 1, the CAS latency = 2, and the READ burst is followed by a “manual” PRECHARGE.
2. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
3. PRECHARGE command not allowed else tRAS would be violated.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
43
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
SINGLE READ – WITH AUTO PRECHARGE
T0
T1
tCK
CLK
tCKS
T2
T3
T4
T5
1
T6
T7
T8
tCL
tCH
tCKH
CKE
tCMS tCMH
COMMAND
ACTIVE
NOP2
NOP
NOP2
READ
tCMS
NOP
NOP
ACTIVE
NOP
tCMH
DQM /
DQML, DQMU
tAS
A0-A9, A11
tAS
A10
COLUMN m3
tAH
ROW
ENABLE AUTO PRECHARGE
ROW
tAS
BA0, BA1
tAH
ROW
ROW
tAH
BANK
BANK
BANK
tAC
t OH
DOUT m
DQ
tRCD
CAS Latency
tHZ
tRP
tRAS
tRC
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
-7E
SYMBOL* MIN MAX MIN MAX
tAC(3)
5.5
5.4
tAC(2)
–
5.4
tAH
1
0.8
tAS
1.5
1.5
tCH
2.5
2.5
tCL
2.5
2.5
tCK(3)
6
7
tCK(2)
–
7.5
tCKH
1
0.8
tCKS
1.5
1.5
-75
MIN MAX
5.4
6
0.8
1.5
2.5
2.5
7.5
10
0.8
1.5
-8E
MIN MAX UNITS
6
ns
6
ns
1
ns
2
ns
3
ns
3
ns
8
ns
10
ns
1
ns
2
ns
-6
-7E
-75
-8E
SYMBOL* MIN MAX MIN MAX MIN MAX MIN MAX UNITS
tCMH
1
0.8
0.8
1
ns
tCMS
1.5
1.5
1.5
2
ns
tHZ(3)
5.5
5.4
5.4
6
ns
tHZ(2)
–
5.4
6
6
ns
tLZ
1
1
1
1
ns
tOH
2
3
3
3
ns
tRAS
42 120,000 37 120,000 44 120,000 50 120,000 ns
tRC
60
60
66
70
ns
tRCD
18
15
20
20
ns
tRP
18
15
20
20
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 1, and the CAS latency = 2.
2. READ command not allowed or tRAS would be violated.
3. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
44
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
ALTERNATING BANK READ ACCESSES
T0
T1
tCK
CLK
T2
T3
T4
T5
NOP
ACTIVE
1
T6
T7
T8
READ
NOP
ACTIVE
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
READ
tCMS
NOP
tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
tAS
A10
COLUMN m 2
tAH
COLUMN b 2
ROW
ENABLE AUTO PRECHARGE
ROW
ENABLE AUTO PRECHARGE
ROW
tAS
BA0, BA1
tAH
ROW
ROW
ROW
tAH
BANK 0
BANK 0
BANK 3
tAC
DQ
tLZ
tRCD - BANK 0
BANK 3
tAC
tOH
DOUT m
tAC
tOH
DOUT m + 1
BANK 0
tAC
tOH
DOUT m + 2
tAC
tOH
DOUT m + 3
tRP - BANK 0
CAS Latency - BANK 0
tAC
tOH
DOUT b
tRCD - BANK 0
tRAS - BANK 0
tRC - BANK 0
tRCD - BANK 3
tRRD
CAS Latency - BANK 3
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
-7E
SYMBOL* MIN MAX MIN MAX
tAC(3)
5.5
5.4
tAC(2)
–
5.4
tAH
1
0.8
tAS
1.5
1.5
tCH
2.5
2.5
tCL
2.5
2.5
tCK(3)
6
7
tCK(2)
–
7.5
tCKH
1
0.8
tCKS
1.5
1.5
-75
-8E
MIN MAX MIN MAX UNITS
5.4
6
ns
6
6
ns
0.8
1
ns
1.5
2
ns
2.5
3
ns
2.5
3
ns
7.5
8
ns
10
10
ns
0.8
1
ns
1.5
2
ns
-6
-7E
-75
-8E
SYMBOL* MIN MAX MIN MAX MIN MAX MIN MAX UNITS
tCMH
1
0.8
0.8
1
ns
tCMS
1.5
1.5
1.5
2
ns
tLZ
1
1
1
1
ns
tOH
2
3
3
3
ns
tRAS
42 120,000 37 120,000 44 120,000 50 120,000 ns
tRC
60
60
66
70
ns
tRCD
18
15
20
20
ns
tRP
18
15
20
20
ns
tRRD
12
14
15
20
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 4, and the CAS latency = 2.
2. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
45
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
READ – FULL-PAGE BURST
T0
T1
T2
tCL
CLK
T3
T4
T5
1
T6
((
))
((
))
tCK
tCH
tCKS
tCMH
ACTIVE
NOP
READ
tCMS
NOP
NOP
NOP
tAS
tCMH
tAS
NOP
BURST TERM
NOP
NOP
((
))
((
))
COLUMN m 2
tAH
((
))
((
))
ROW
tAS
BA0, BA1
Tn + 4
((
))
((
))
tAH
ROW
((
))
((
))
NOP
DQM /
DQML, DQMH
A10
Tn + 3
((
))
((
))
tCMS
A0-A9, A11
Tn + 2
tCKH
CKE
COMMAND
Tn + 1
tAH
BANK
((
))
((
))
BANK
tAC
tAC
tOH
DOUT m
DQ
tLZ
tRCD
CAS Latency
tAC
tAC ( (
tOH ) )
tOH
((
))
((
))
DOUT m+1
DOUT m+2
tAC
tOH
DOUT m-1
256 (x16) locations within same row
512 (x8) locations within same row
1,024 (x4) locations within same row
tAC
tOH
DOUT m
tOH
DOUT m+1
tHZ
DON’T CARE
Full page completed
Full-page burst does not self-terminate.
3
Can use BURST TERMINATE command.
UNDEFINED
TIMING PARAMETERS
SYMBOL*
tAC(3)
tAC(2)
tAH
tAS
tCH
tCL
tCK(3)
tCK(2)
tCKH
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
5.5
5.4
5.4
6
ns
–
5.4
6
6
ns
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
2.5
2.5
2.5
3
ns
2.5
2.5
2.5
3
ns
6
7
7.5
8
ns
–
7.5
10
10
ns
1
0.8
0.8
1
ns
SYMBOL*
tCKS
tCMH
tCMS
tHZ(3)
tHZ(2)
tLZ
tOH
tRCD
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1.5
1.5
1.5
2
ns
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
5.5
5.4
5.4
6
ns
–
5.4
6
6
ns
1
1
1
1
ns
2
3
3
3
ns
18
15
20
20
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the CAS latency = 2.
2. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
3. Page left open; no tRP.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
46
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
READ – DQM OPERATION
T0
T1
tCK
CLK
tCKS
tCKH
tCMS
tCMH
T2
T3
T4
NOP
NOP
1
T5
T6
T7
T8
NOP
NOP
NOP
tCL
tCH
CKE
COMMAND
ACTIVE
NOP
READ
tCMS
NOP
tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
tAH
ENABLE AUTO PRECHARGE
ROW
tAS
BA0, BA1
COLUMN m 2
ROW
tAS
A10
tAH
DISABLE AUTO PRECHARGE
tAH
BANK
BANK
tAC
DQ
tOH
DOUT m
tLZ
tRCD
tAC
tOH
tAC
tHZ
tOH
DOUT m + 2
DOUT m + 3
tLZ
tHZ
CAS Latency
DON’T CARE
UNDEFINED
TIMING PARAMETERS
SYMBOL*
tAC(3)
tAC(2)
tAH
tAS
tCH
tCL
tCK(3)
tCK(2)
tCKH
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
5.5
5.4
5.4
6
ns
–
5.4
6
6
ns
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
2.5
2.5
2.5
3
ns
2.5
2.5
2.5
3
ns
6
7
7.5
8
ns
–
7.5
10
10
ns
1
0.8
0.8
1
ns
SYMBOL*
tCKS
tCMH
tCMS
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1.5
1
1.5
tHZ(3)
5.5
–
tHZ(2)
tLZ
tOH
tRCD
1.5
0.8
1.5
1
2
18
1.5
0.8
1.5
5.4
5.4
1
3
15
2
1
2
5.4
6
1
3
20
6
6
1
3
20
ns
ns
ns
ns
ns
ns
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 4, and the CAS latency = 2.
2. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
47
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
WRITE – WITHOUT AUTO PRECHARGE
T0
tCK
CLK
T1
T2
tCL
T3
T4
T5
NOP
NOP
NOP
1
T6
T7
T8
NOP
ACTIVE
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
WRITE
PRECHARGE
tCMS tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
ROW
tAH
ALL BANKS
ROW
tAS
BA0, BA1
COLUMN m 3
ROW
tAS
A10
tAH
ROW
DISABLE AUTO PRECHARGE
tAH
BANK
SINGLE BANK
BANK
tDS
BANK
tDH
DIN m
DQ
tDS
tDH
DIN m + 1
tDS
tDH
DIN m + 2
tDS
DIN m + 3
t WR 2
tRCD
tRAS
BANK
tDH
tRP
tRC
DON’T CARE
TIMING PARAMETERS
-6
-7E
SYMBOL* MIN MAX MIN MAX
tAH
1
0.8
tAS
1.5
1.5
tCH
2.5
2.5
tCL
2.5
2.5
tCK(3)
6
7
tCK(2)
–
7.5
tCKH
1
0.8
tCKS
1.5
1.5
tCMH
1
0.8
-75
MIN MAX
0.8
1.5
2.5
2.5
7.5
10
0.8
1.5
0.8
-8E
MIN MAX UNITS
1
ns
2
ns
3
ns
3
ns
8
ns
10
ns
1
ns
2
ns
1
ns
-6
-7E
-75
-8E
SYMBOL* MIN MAX MIN MAX MIN MAX MIN MAX UNITS
tCMS
1.5
1.5
1.5
2
ns
tDH
1
0.8
0.8
1
ns
tDS
1.5
1.5
1.5
2
ns
tRAS
42 120,000 37 120,000 44 120,000 50 120,000 ns
tRC
60
60
66
70
ns
tRCD
18
15
20
20
ns
tRP
18
15
20
20
ns
tWR
12
14
15
15
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 4, and the WRITE burst is followed by a “manual” PRECHARGE.
2. 15ns is required between and the PRECHARGE command, regardless of frequency.
3. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
48
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
WRITE – WITH AUTO PRECHARGE
T0
tCK
CLK
tCKS
tCKH
tCMS
tCMH
T1
T2
tCL
1
T3
T4
T5
T6
T7
T8
T9
NOP
NOP
NOP
NOP
NOP
NOP
ACTIVE
tCH
CKE
COMMAND
ACTIVE
NOP
WRITE
tCMS tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
tAS
A10
COLUMN m 2
tAH
ROW
ENABLE AUTO PRECHARGE
ROW
tAS
BA0, BA1
tAH
ROW
ROW
tAH
BANK
BANK
tDS
tDH
DIN m
DQ
BANK
tDS
tDH
DIN m + 1
tDS
tDH
DIN m + 2
tRCD
tRAS
tDS
tDH
DIN m + 3
tWR
tRP
tRC
DON’T CARE
TIMING PARAMETERS
-6
-7E
-75
-8E
SYMBOL* MIN MAX MIN MAX MIN MAX MIN MAX UNITS
tAH
1
0.8
0.8
1
ns
tAS
1.5
1.5
1.5
2
ns
tCH
2.5
2.5
2.5
3
ns
tCL
2.5
2.5
2.5
3
ns
tCK(3)
6
7
7.5
8
ns
tCK(2)
–
7.5
10
10
ns
tCKH
1
0.8
0.8
1
ns
tCKS
1.5
1.5
1.5
2
ns
tCMH
1
0.8
0.8
1
ns
-6
-7E
-75
-8E
SYMBOL* MIN MAX MIN MAX MIN MAX MIN MAX UNITS
tCMS
1.5
1.5
1.5
2
ns
tDH
1
0.8
0.8
1
ns
tDS
1.5
1.5
1.5
2
ns
tRAS
42 120,000 37 120,000 44 120,000 50 120,000 ns
tRC
60
60
66
70
ns
tRCD
18
15
20
20
ns
tRP
18
15
20
20
ns
tWR
1 CLK
1 CLK
1 CLK
1 CLK
–
+ 6ns
+ 7ns
+ 7.5ns
+ 7ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 4.
2. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
49
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
SINGLE WRITE – WITHOUT AUTO PRECHARGE
T0
tCK
CLK
T1
T2
tCL
T3
T4
T5
T6
1
T7
T8
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
NOP4
WRITE
NOP4
PRECHARGE
NOP
ACTIVE
NOP
tCMS tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
tAS
A10
COLUMN m 3
tAH
ALL BANKS
ROW
tAS
BA0, BA1
tAH
ROW
ROW
DISABLE AUTO PRECHARGE
tAH
BANK
SINGLE BANK
BANK
tDS
BANK
BANK
tDH
DIN m
DQ
t WR 2
tRCD
tRAS
tRP
tRC
DON’T CARE
TIMING PARAMETERS
-6
-7E
SYMBOL* MIN MAX MIN MAX
tAH
1
0.8
tAS
1.5
1.5
tCH
2.5
2.5
tCL
2.5
2.5
tCK(3)
6
7
tCK(2)
–
7.5
tCKH
1
0.8
tCKS
1.5
1.5
tCMH
1
0.8
-75
MIN MAX
0.8
1.5
2.5
2.5
7.5
10
0.8
1.5
0.8
-8E
MIN MAX UNITS
1
ns
2
ns
3
ns
3
ns
8
ns
10
ns
1
ns
2
ns
1
ns
-6
-7E
-75
-8E
SYMBOL* MIN MAX MIN MAX MIN MAX MIN MAX UNITS
tCMS
1.5
1.5
1.5
2
ns
tDH
1
0.8
0.8
1
ns
tDS
1.5
1.5
1.5
2
ns
tRAS
42 120,000 37 120,000 44 120,000 50 120,000 ns
tRC
60
60
66
70
ns
tRCD
18
15
20
20
ns
tRP
18
15
20
20
ns
tWR
12
14
15
15
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 1, and the WRITE burst is followed by a “manual” PRECHARGE.
2. 15ns is required between and the PRECHARGE command, regardless of frequency.
3. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
4. PRECHARGE command not allowed else tRAS would be violated.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
50
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
SINGLE WRITE – WITH AUTO PRECHARGE
T0
tCK
CLK
tCKS
tCKH
tCMS
tCMH
T1
tCL
T2
T3
1
T4
T5
T6
T7
WRITE
NOP
NOP
NOP
T8
T9
tCH
CKE
COMMAND
NOP3
ACTIVE
NOP3
NOP3
tCMS
ACTIVE
NOP
tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
tAH
ROW
ENABLE AUTO PRECHARGE
ROW
tAS
BA0, BA1
COLUMN m 2
ROW
tAS
A10
tAH
ROW
tAH
BANK
BANK
tDS
BANK
tDH
DIN m
DQ
tRCD
tRAS
tWR
tRP
tRC
DON’T CARE
TIMING PARAMETERS
-6
-7E
-75
-8E
SYMBOL* MIN MAX MIN MAX MIN MAX MIN MAX UNITS
tAH
1
0.8
0.8
1
ns
tAS
1.5
1.5
1.5
2
ns
tCH
2.5
2.5
2.5
3
ns
tCL
2.5
2.5
2.5
3
ns
tCK(3)
6
7
7.5
8
ns
tCK(2)
–
7.5
10
10
ns
tCKH
1
0.8
0.8
1
ns
tCKS
1.5
1.5
1.5
2
ns
tCMH
1
0.8
0.8
1
ns
-6
-7E
-75
-8E
SYMBOL* MIN MAX MIN MAX MIN MAX MIN MAX UNITS
tCMS
1.5
1.5
1.5
2
ns
tDH
1
0.8
0.8
1
ns
tDS
1.5
1.5
1.5
2
ns
tRAS
42 120,000 37 120,000 44 120,000 50 120,000 ns
tRC
60
60
66
70
ns
tRCD
18
15
20
20
ns
tRP
18
15
20
20
ns
tWR
1 CLK
1 CLK
1 CLK
1 CLK
–
+ 6ns
+ 7ns
+ 7.5ns
+ 7ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 1.
2. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
3. WRITE command not allowed else tRAS would be violated.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
51
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
ALTERNATING BANK WRITE ACCESSES
T0
tCK
CLK
T1
T2
tCL
T3
T4
T5
1
T6
T7
T8
T9
NOP
NOP
ACTIVE
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
WRITE
tCMS
NOP
ACTIVE
NOP
WRITE
tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
tAS
A10
COLUMN m 2
tAH
COLUMN b 2
ROW
ENABLE AUTO PRECHARGE
ROW
ENABLE AUTO PRECHARGE
ROW
tAS
BA0, BA1
tAH
ROW
ROW
ROW
tAH
BANK 0
BANK 0
tDS
tDH
DIN m
DQ
BANK 1
tDS
tDH
DIN m + 1
tDS
BANK 1
tDH
tDS
DIN m + 2
tDH
DIN m + 3
tRCD - BANK 0
tDS
tDH
DIN b
tWR - BANK 0
BANK 0
tDS
tDH
tDS
DIN b + 1
tDH
DIN b + 2
tRP - BANK 0
tDS
tDH
DIN b + 3
tRCD - BANK 0
tRAS - BANK 0
tRC - BANK 0
tWR - BANK 1
tRCD - BANK 1
tRRD
DON’T CARE
TIMING PARAMETERS
-6
-7E
-75
SYMBOL* MIN MAX MIN MAX MIN MAX
tAH
1
0.8
0.8
tAS
1.5
1.5
1.5
tCH
2.5
2.5
2.5
tCL
2.5
2.5
2.5
tCK(3)
6
7
7.5
tCK(2)
–
7.5
10
tCKH
1
0.8
0.8
tCKS
1.5
1.5
1.5
tCMH
1
0.8
0.8
tCMS
1.5
1.5
1.5
-8E
MIN MAX UNITS
1
ns
2
ns
3
ns
3
ns
8
ns
10
ns
1
ns
2
ns
1
ns
2
ns
-6
-7E
SYMBOL* MIN MAX MIN MAX
tDH
tDS
tRAS
tRC
tRCD
tRP
tRRD
tWR
-75
MIN MAX
-8E
MIN MAX UNITS
1
0.8
0.8
1
1.5
1.5
1.5
2
42 120,000 37 120,000 44 120,000 50 120,000
60
60
66
70
18
15
20
20
18
15
20
20
12
14
15
20
1 CLK
1 CLK
1 CLK
1 CLK
+ 6ns
+ 7ns
+ 7.5ns
+ 7ns
ns
ns
ns
ns
ns
ns
ns
–
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 4.
2. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
52
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
WRITE – FULL-PAGE BURST
T0
T1
T2
tCL
CLK
T3
T4
T5
((
))
((
))
tCK
tCH
tCKS
tCKH
tCMS
tCMH
ACTIVE
NOP
WRITE
NOP
NOP
NOP
tCMS tCMH
tAS
A10
((
))
((
))
NOP
BURST TERM
NOP
((
))
((
))
COLUMN m 1
tAH
((
))
((
))
ROW
tAS
BA0, BA1
tAH
ROW
tAS
Tn + 3
((
))
((
))
DQM /
DQML, DQMH
A0-A9, A11
Tn + 2
((
))
((
))
CKE
COMMAND
Tn + 1
tAH
BANK
((
))
((
))
BANK
tDS
tDH
DIN m
DQ
tDS
tDH
tDS
DIN m + 1
tDH
tDS
DIN m + 2
tDH
DIN m + 3
tRCD
((
))
((
))
tDS
tDH
tDS
tDH
DIN m - 1
256 (x16) locations within same row
512 (x8) locations within same row
1,024 (x4) locations within same row
Full-page burst does
not self-terminate. Can
use BURST TERMINATE
command to stop.2, 3
DON’T CARE
Full page completed
TIMING PARAMETERS
SYMBOL*
tAH
tAS
tCH
tCL
tCK(3)
tCK(2)
tCKH
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
2.5
2.5
2.5
3
ns
2.5
2.5
2.5
3
ns
6
7
7.5
8
ns
–
7.5
10
10
ns
1
0.8
0.8
1
ns
SYMBOL*
tCKS
tCMH
tCMS
tDH
tDS
tRCD
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1.5
1
1.5
1
1.5
18
1.5
0.8
1.5
0.8
1.5
15
1.5
0.8
1.5
0.8
1.5
20
2
1
2
1
2
20
ns
ns
ns
ns
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
t
2. WR must be satisfied prior to PRECHARGE command.
3. Page left open; no tRP.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
53
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
WRITE – DQM OPERATION
T0
T1
tCK
CLK
T2
1
T3
T4
T5
NOP
NOP
NOP
T6
T7
NOP
NOP
tCL
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
WRITE
tCMS tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
tAH
ENABLE AUTO PRECHARGE
ROW
tAS
BA0, BA1
COLUMN m 2
ROW
tAS
A10
tAH
tAH
DISABLE AUTO PRECHARGE
BANK
BANK
tDS
tDH
tDS
DIN m
DQ
tDH
DIN m + 2
tDS
tDH
DIN m + 3
tRCD
DON’T CARE
TIMING PARAMETERS
SYMBOL*
tAH
tAS
tCH
tCL
tCK(3)
tCK(2)
tCKH
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
2.5
2.5
2.5
3
ns
2.5
2.5
2.5
3
ns
6
7
7.5
8
ns
–
7.5
10
10
ns
1
0.8
0.8
1
ns
SYMBOL*
tCKS
tCMH
tCMS
tDH
tDS
tRCD
-6
-7E
-75
-8E
MIN MAX MIN MAX MIN MAX MIN MAX UNITS
1.5
1.5
1.5
2
ns
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
1
0.8
0.8
1
ns
1.5
1.5
1.5
2
ns
18
15
20
20
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 4.
2. x16: A8, A9 and A11 = “Don’t Care”
x8: A9 and A11 = “Don’t Care”
x4: A11 = “Don’t Care”
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
54
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.
64Mb: x4, x8, x16
SDRAM
54-PIN PLASTIC TSOP (400 mil)
SEE DETAIL A
22.22 ±.08
.71
.80 TYP
2X 0.10
.375 ±.075 TYP
2.80
11.76 ±0.20
10.16 ±0.08
R 2X 0.75
0.15
PIN #1 ID
+0.03
-0.02
GAGE PLANE
R 2X 1.00
0.25
0.10
0.10
PLATED LEAD FINISH: 90% Sn, 10% Pb OR 100%Sn
+0.10
-0.05
0.50 ±0.10
1.2 MAX
0.80
TYP
PLASTIC PACKAGE MATERIAL: EPOXY NOVOLAC
PACKAGE WIDTH AND LENGTH DO NOT
INCLUDE MOLD PROTRUSION. ALLOWABLE
PROTRUSION IS 0.25 PER SIDE.
DETAIL A
NOTE: 1. All dimensions in millimeters.
2. Package width and length do not include mold protrusion; allowable mold protrusion is 0.25mm per side.
8000 S. Federal Way, P.O. Box 6, Boise, ID 83707-0006, Tel: 208-368-3900
E-mail: prodmktg@micron.com, Internet: http://www.micron.com, Customer Comment Line: 800-932-4992
Micron, the M logo, and the Micron logo are trademarks of Micron Technology, Inc.
All other trademarks are the property of their respective owners.
64Mb: x4, x8, x16 SDRAM
64MSDRAM.pmd – Rev. H; Pub. 12/04
55
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2002 Micron Technology, Inc. All rights reserved.