MICRON MT48LC1M16A1S

16Mb: x16
SDRAM
SYNCHRONOUS
DRAM
MT48LC1M16A1 S - 512K x 16 x 2 banks
For the latest data sheet, please refer to the Micron Web
site: www.micronsemi.com/datasheets/sdramds.html
FEATURES
PIN ASSIGNMENT (Top View)
50-Pin TSOP
• PC100 functionality
• 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
1 Meg x 16 - 512K x 16 x 2 banks architecture with
11 row, 8 column addresses per bank
• Programmable burst lengths: 1, 2, 4, 8 or full page
• Auto Precharge Mode, includes CONCURRENT
AUTO PRECHARGE
• Self Refresh and Adaptable Auto Refresh Modes
- 32ms, 2,048-cycle refresh or
- 64ms, 2,048-cycle refresh or
- 64ms, 4,096-cycle refresh
• LVTTL-compatible inputs and outputs
• Single +3.3V ±0.3V power supply
• Supports CAS latency of 1, 2 and 3
OPTIONS
VDD
DQ0
DQ1
VssQ
DQ2
DQ3
VDDQ
DQ4
DQ5
VssQ
DQ6
DQ7
VDDQ
DQML
WE#
CAS#
RAS#
CS#
BA
A10
A0
A1
A2
A3
VDD
MARKING
• Configuration
1 Meg x 16 (512K x 16 x 2 banks)
1M16A1
• Plastic Package - OCPL*
50-pin TSOP (400 mil)
TG
• Timing (Cycle Time)
6ns (166 MHz)
7ns (143 MHz)
8ns (125 MHz)
-6
-7
-8A
• Refresh
2K or 4K with Self Refresh Mode at 64ms
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
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
Vss
DQ15
DQ14
VssQ
DQ13
DQ12
VDDQ
DQ11
DQ10
VssQ
DQ9
DQ8
VDDQ
NC
DQMH
CLK
CKE
NC
A9
A8
A7
A6
A5
A4
Vss
Note: The # symbol indicates signal is active LOW.
Configuration
Refresh Count
Row Addressing
Bank Addressing
Column Addressing
1 Meg x 16
512K x 16 x 2 banks
2K or 4K
2K (A0-A10)
2 (BA)
256 (A0-A7)
16MB (X16) SDRAM PART NUMBER
S
PART NUMBER
MT48LC1M16A1TG S
Part Number Example:
ARCHITECTURE
1 Meg x 16
MT48LC1M16A1TG-7S
GENERAL DESCRIPTION
KEY TIMING PARAMETERS
SPEED
CLOCK
-6
-7
-8A
166 MHz
143 MHz
125 MHz
ACCESS TIME
CL = 3**
5.5ns
5.5ns
6ns
SETUP
HOLD
2ns
2ns
2ns
1ns
1ns
1ns
The 16Mb SDRAM is a high-speed CMOS, dynamic
random-access memory containing 16,777,216 bits. It
is internally configured as a dual 512K x 16 DRAM with
a synchronous interface (all signals are registered on
the positive edge of the clock signal, CLK). Each of the
512K x 16-bit banks is organized as 2,048 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
*Off-center parting line
**CL = CAS (READ) latency
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
1
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
GENERAL DESCRIPTION (continued)
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 (BA selects the bank, A0-A10 select the row).
The address 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
self-timed row precharge that is initiated at the end of
the burst sequence.
The 1 Meg x 16 SDRAM uses an internal pipelined
architecture to achieve high-speed operation. This architecture is compatible with the 2n rule of prefetch
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
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 the alternate bank will hide the PRECHARGE
cycles and provide seamless, high-speed, random-access operation.
The 1 Meg x 16 SDRAM is designed to operate in
3.3V, low-power memory systems. An auto refresh
mode is provided, along with a power-saving, powerdown 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.
2
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
TABLE OF CONTENTS
Functional Block Diagram - 1 Meg x 16 ................. 3
Pin Descriptions ........................................................ 4
Functional Description ........................................
Initialization ........................................................
Register Definitions .............................................
Mode Register ................................................
Burst Length ..............................................
Burst Type .................................................
CAS Latency ..............................................
Operating Mode .......................................
Write Burst Mode .....................................
Commands ..............................................................
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 ......................................
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
Concurrent Auto Precharge ................................ 22
Truth Table 2 (CKE) ................................................... 24
Truth Table 3 (Current State, Same Bank) ....................... 25
Truth Table 4 (Current State, Different Bank) ................... 27
Absolute Maximum Ratings .................................... 29
DC Electrical Characteristics and Operating Conditions
29
IDD Specifications and Conditions .......................... 29
Capacitance .............................................................. 30
5
5
5
5
5
5
7
7
7
8
8
9
9
9
9
9
9
9
9
9
10
10
11
11
12
18
20
20
21
21
AC Electrical Characteristics (Timing Table) .... 30
Timing Waveforms
Initialize and Load Mode Register ......................
Power-Down Mode ............................................
Clock Suspend Mode ..........................................
Auto Refresh Mode .............................................
Self Refresh Mode ...............................................
Reads
Read - Single Read .........................................
Read - Without Auto Precharge ....................
Read - With Auto Precharge ..........................
Alternating Bank Read Accesses ....................
Read - Full-Page Burst ....................................
Read - DQM Operation .................................
Writes
Write - Single Write .......................................
Write - Without Auto Precharge ...................
Write - With Auto Precharge .........................
Alternating Bank Write Accesses ...................
Write - Full-Page Burst ...................................
Write - DQM Operation ................................
3
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
ROWADDRESS
LATCH
11
11
ROW
DECODER
FUNCTIONAL BLOCK DIAGRAM
1 Meg x 16 SDRAM
2,048
BANK0
MEMORY
ARRAY
(2,048 x 256 x 16)
CKE
CLK
DQML,
DQMH
COMMAND
DECODE
CS#
WE#
CAS#
RAS#
256 (x16)
CONTROL
LOGIC
SENSE AMPLIFIERS
I/O GATING
DQM MASK LOGIC
MODE REGISTER
16
COLUMNADDRESS BUFFER
8
BURST COUNTER
12
COLUMNADDRESS LATCH
256
8
DATA
OUTPUT
REGISTER
16
COLUMN
DECODER
DQ0DQ15
16
DATA
INPUT8
REGISTER
256
A0-A10, BA
12
REFRESH
CONTROLLER
ADDRESS
REGISTER
REFRESH
COUNTER
SENSE AMPLIFIERS
I/O GATING
DQM MASK LOGIC
11
ROWADDRESS
MUX
256 (x16)
11
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
ROWADDRESS
LATCH
11
ROW
DECODER
11
2,048
4
BANK1
MEMORY
ARRAY
(2,048 x 256 x 16)
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
PIN DESCRIPTIONS
PIN NUMBERS
SYMBOL
35
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.
34
CKE
Input Clock Enable: CKE activates (HIGH) and deactivates (LOW) the CLK
signal. Deactivating the clock provides PRECHARGE POWER-DOWN
and SELF REFRESH operations (all banks idle), ACTIVE POWER-DOWN
(row ACTIVE in either 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.
18
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.
15, 16, 17
WE#, CAS#,
RAS#
Input Command Inputs: RAS#, CAS# and WE# (along with CS#) define the
command being entered.
14, 36
DQML,
DQMH
19
BA
21-24, 27-32, 20
A0-A10
2, 3, 5, 6, 8, 9,
11, 12, 39, 40, 42,
43, 45, 46, 48, 49
33, 37
DQ0DQ15
7, 13, 38, 44
VDDQ
4, 10, 41, 47
VSSQ
1, 25
VDD
Supply Power Supply: +3.3V ±0.3V.
26, 50
VSS
Supply Ground.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
NC
TYPE
DESCRIPTION
Input 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. DQML corresponds to DQ0-DQ7; DQMH
corresponds to DQ8-DQ15.
DQML and DQMH are considered same state when referenced as DQM.
Input Bank Address Inputs: BA defines to which bank the ACTIVE, READ,
WRITE or PRECHARGE command is being applied. BA is also used to
program the twelfth bit of the Mode Register.
Input Address Inputs: A0-A10 are sampled during the ACTIVE command
(row-address A0-A10) and READ/WRITE command (column-address A0A7, with A10 defining AUTO PRECHARGE) to select one location out of
the 512K available in the respective bank. A10 is sampled during a
PRECHARGE command to determine if all banks are to be precharged
(A10 HIGH). The address inputs also provide the op-code during a
LOAD MODE REGISTER command.
Input/ Data I/Os: Data bus.
Output
–
No Connect: These pins should be left unconnected.
Supply DQ Power: Provide isolated power to DQs for improved noise immunity.
Supply DQ Ground: Provide isolated ground to DQs for improved noise
immunity.
5
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
FUNCTIONAL DESCRIPTION
REGISTER DEFINITION
In general, the SDRAM is a dual 512K x 16 DRAM
that operates at 3.3V and includes a synchronous
interface (all signals are registered on the positive edge
of the clock signal, CLK). Each of the 512K x 16-bit
banks is organized as 2,048 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 (BA
selects the bank, A0-A10 select the row). The address
bits (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 fullpage 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-A7 when the burst length is set to two,
by A2-A7 when the burst length is set to four and by A3A7 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 applying 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 then 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.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
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.
6
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©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
BA
11
A10
10
A9
9
A8
8
A6
A7
6
7
A5
5
A4
A3
4
Reserved* WB Op Mode CAS Latency
3
2
BT
A1
A2
1
0
Table 1
Burst Definition
Address Bus
A0
Mode Register (Mx)
Burst
Length
Burst Length
*Should program
M11, M10 = 0, 0
to ensure compatibility
with future devices.
Burst Length
2
M2 M1M0
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
4
Burst Type
M3
0
Sequential
1
Interleave
M6 M5M4
CAS Latency
0 0 0
Reserved
0 0 1
1
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
8
Full
Page
(256)
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
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
n = A0-A7
Cn+3, Cn+4...
…Cn-1,
(location 0-255)
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 a burst length of two, A1-A7 select the block
of two burst; A0 selects the starting column
within the block.
2. For a burst length of four, A2-A7 select the block
of four burst; A0-A1 select the starting column
within the block.
3. For a burst length of eight, A3-A7 select the block
of eight burst; A0-A2 select the starting column
within the block.
4. For a full-page burst, the full row is selected and
A0-A7 select the starting column.
5. Whenever a boundary of the block is reached
within a given sequence above, the following
access wraps within the block.
6. For a burst length of one, A0-A7 select the unique
column to be accessed, and Mode Register bit M3
is ignored.
All other states reserved
Figure 1
Mode Register Definition
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
Starting Column
Order of Accesses Within a Burst
Address
Type = Sequential Type = Interleaved
7
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: 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 1, 2 or 3 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 below
indicates the operating frequencies at which each CAS
latency setting can be used.
T0
T1
READ
NOP
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.
T2
CLK
COMMAND
tLZ
tOH
Table 2
CAS Latency
DOUT
DQ
tAC
CAS Latency = 1
T0
T1
T2
ALLOWABLE OPERATING
FREQUENCY (MHz)
T3
CLK
SPEED
COMMAND
READ
NOP
NOP
tLZ
tOH
DOUT
DQ
tAC
CAS
CAS
CAS
LATENCY = 1 LATENCY = 2 LATENCY = 3
-6
≤ 50
≤ 125
≤ 166
-7
≤ 40
≤ 100
≤ 143
-8A
≤ 40
≤ 77
≤ 125
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
Figure 2
CAS Latency
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
8
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: 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
(Notes: 1)
NAME (FUNCTION)
CS# RAS# CAS# WE# DQM ADDR
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
WRITE (Select bank and column and
start WRITE burst)
H
L
X
X
X
X
X
X
Bank/Row
X
3
H
L/H8
Bank/Col
X
4
L
L/H8
Bank/Col Valid
4
L
H
BURST TERMINATE
L
H
H
L
X
X
Active
PRECHARGE (Deactivate row in bank or banks)
L
L
H
L
X
Code
X
5
AUTO REFRESH or
SELF REFRESH (Enter self refresh mode)
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
NOTE: 1.
2.
3.
4.
5.
6.
7.
8.
L
DQs NOTES
CKE is HIGH for all commands shown except SELF REFRESH.
A0-A10 and BA define the op-code written to the Mode Register.
A0-A10 provide row address, and BA determines which bank is made active.
A0-A7 provide column address; A10 HIGH enables the auto precharge feature (nonpersistent), while A10 LOW disables
the auto precharge feature; BA determines which bank is being read from or written to.
For A10 LOW, BA determines which bank is being precharged; for A10 HIGH, all banks are precharged and BA is a
“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).
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
9
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©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
WRITE
The WRITE command is used to initiate a burst
write access to an active row. The value on the BA input
selects the bank, and the address provided on inputs
A0-A7 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 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.
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.
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.
LOAD MODE REGISTER
The Mode Register is loaded via inputs A0-A10 and
BA. See Mode Register heading in 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.
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, input BA selects the
bank. Otherwise BA is 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.
ACTIVE
The ACTIVE command is used to open (or activate)
a row in a particular bank for a subsequent access. The
value on the BA input selects the bank, and the address
provided on inputs A0-A10 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.
READ
The READ command is used to initiate a burst read
access to an active row. The value on the BA input
selects the bank, and the address provided on inputs
A0-A7 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.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
AUTO PRECHARGE
AUTO PRECHARGE is a feature which performs the
same individual-bank PRECHARGE function described
above, but 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.
10
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©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
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.
mands distributed every 15.625µs would allow the 1
Meg x 16 SDRAM to have a 4K refresh if required. Of
the three types of refreshs options, utilizing the 2,048
cycles every 64ms (31.25µs per refresh) provides the
maximum power savings.
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
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 self refresh mode, AUTO REFRESH
commands may be issued every 15.625µs or less as both
SELF REFRESH and AUTO REFRESH utilize the row
refresh counter.
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.
AUTO REFRESH
AUTO REFRESH is used during normal operation
of the SDRAM and is analogous to CAS#-BEFORERAS# (CBR) REFRESH in conventional DRAMs. This
command is nonpersistent, so it must be issued each
time a refresh is required.
The addressing during an AUTO REFRESH command is generated by an internal refresh controller.
This means that the address lines are not used to
generate the refresh address, and are “Don’t Care”.
The 1 Meg x 16 SDRAM requires 2,048 AUTO
REFRESH cycles every 64ms (tREF) to ensure that each
row is refreshed. Distributed refresh would be achieved
by providing an AUTO REFRESH command once every 31.25µs. Burst refresh could be accomplished by
issuing 2,048 AUTO REFRESH commands consecutively at the minimum cycle rate of tRC.
To provide a 4K refresh scheme, the refresh rate
would be doubled. Thus, 2,048 AUTO-REFRESH com-
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
11
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
OPERATION
CLK
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 issued. 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
tRRD.
T0
CKE
HIGH
CS#
RAS#
CAS#
WE#
ROW
ADDRESS
A0-A10
BANK 1
BA
BANK 0
Figure 3
Activating a Specific Row in a
Specific Bank
T1
T2
NOP
NOP
T3
T4
CLK
COMMAND
ACTIVE
READ or
WRITE
tRCD
DON’T CARE
Example: Meeting
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
tRCD
Figure 4
(MIN) When 2 < tRCD (MIN)/tCK ≤ 3
12
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: 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 HighZ. 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 subsequent 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 before the clock edge at which the last desired
CLK
CKE
T0
T1
T2
READ
NOP
CLK
COMMAND
HIGH
tLZ
tOH
DOUT
DQ
CS#
tAC
CAS Latency = 1
RAS#
T0
T1
T2
T3
READ
NOP
NOP
CLK
CAS#
COMMAND
tLZ
WE#
tOH
DOUT
DQ
tAC
A0-A7
COLUMN
ADDRESS
CAS Latency = 2
A8-A9
T0
T1
T2
T3
T4
READ
NOP
NOP
NOP
CLK
ENABLE AUTO PRECHARGE
A10
COMMAND
DISABLE AUTO PRECHARGE
tLZ
DOUT
DQ
BANK 1
tOH
tAC
BA
CAS Latency = 3
BANK 0
DON’T CARE
Figure 5
READ Command
UNDEFINED
Figure 6
CAS Latency
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
13
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16Mb: x16
SDRAM
data element is valid, where x equals the CAS latency
minus one. This is shown in Figure 7 for READ latencies
of one, 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 1 Meg x 16 SDRAM uses a pipelined architec-
T0
T1
T2
ture 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. Full-speed, random read accesses
within a page can be performed as shown in Figure 8.
T3
T4
T5
CLK
COMMAND
READ
NOP
NOP
NOP
NOP
READ
X = 0 cycles
ADDRESS
BANK,
COL n
BANK,
COL b
DOUT
n
DQ
DOUT
n+2
DOUT
n+1
DOUT
n+3
DOUT
b
CAS Latency = 1
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
DQ
DOUT
n+2
DOUT
n+1
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
NOP
READ
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
NOTE: Each READ command may be to either bank. DQM is LOW.
DON’T CARE
Figure 7
Consecutive READ Bursts
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
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16Mb: x16
SDRAM
T0
T1
T2
T3
T4
CLK
COMMAND
READ
READ
READ
READ
ADDRESS
BANK,
COL n
BANK,
COL a
BANK,
COL x
BANK,
COL m
DOUT
n
DQ
NOP
DOUT
x
DOUT
a
DOUT
m
CAS Latency = 1
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
DOUT
n
DQ
NOP
DOUT
a
NOP
DOUT
x
NOP
DOUT
m
CAS Latency = 3
NOTE: Each READ command may be to either bank. DQM is LOW.
DON’T CARE
Figure 8
Random READ Accesses
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
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©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
Data from any READ burst may be truncated with
a subsequent WRITE command, and data from a
fixed-length READ burst may be immediately followed
by data from a subsequent 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 the possibility that
the device driving the input data would 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 (DQM latency is
two clocks for output buffers) prior to the WRITE
T0
T1
T2
T3
command 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 (DQM latency
is zero clocks for input buffers) prior to the WRITE
command 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.
T0
T4
CLK
CLK
DQM
DQM
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
WRITE
BANK,
COL b
COMMAND
READ
ADDRESS
BANK,
COL n
tHZ
DOUT n
DQ
NOP
T3
T4
NOP
NOP
DOUT n
WRITE
DIN b
tDS
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.
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.
DON’T CARE
Figure 10
READ to WRITE with
Extra Clock Cycle
Figure 9
READ to WRITE
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
T5
BANK,
COL b
DIN b
tDS
NOTE:
NOP
T2
tHZ
tCK
DQ
T1
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16Mb: 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
T0
T1
T2
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 fixedlength burst with AUTO PRECHARGE. The disadvanT3
T4
T5
T6
T7
CLK
t RP
COMMAND
READ
NOP
NOP
NOP
PRECHARGE
NOP
NOP
ACTIVE
X = 0 cycles
ADDRESS
BANK
(a or all)
BANK a,
COL n
DOUT
n+2
DOUT
n+1
DOUT
n
DQ
BANK a,
ROW
DOUT
n+3
CAS Latency = 1
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+2
DOUT
n+1
DOUT
n
DQ
BANK a,
ROW
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
BANK a,
ROW
DOUT
n+2
DOUT
n+1
DOUT
n+3
CAS Latency = 3
NOTE: DQM is LOW.
DON’T CARE
Figure 11
READ to PRECHARGE
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
17
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16Mb: x16
SDRAM
tage 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.
Full-page READ bursts can be truncated with the
BURST TERMINATE command, and fixed-length
READ bursts may be truncated with a BURST TERMI-
T0
T1
T2
NATE 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.
T3
T4
T5
T6
CLK
COMMAND
READ
ADDRESS
BANK,
COL n
NOP
NOP
NOP
BURST
TERMINATE
NOP
NOP
X = 0 cycles
DOUT
n+2
DOUT
n+1
DOUT
n
DQ
DOUT
n+3
CAS Latency = 1
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
NOTE: DQM is LOW.
DON’T CARE
Figure 12
Terminating a READ Burst
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
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16Mb: 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 subsequent 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 1 Meg x 16 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,
T0
T1
T2
T3
COMMAND
WRITE
NOP
NOP
NOP
ADDRESS
BANK,
COL n
CLK
NOTE:
Burst length = 2. DQM is LOW.
Figure 14
WRITE Burst
CLK
CKE
DIN
n+1
DIN
n
DQ
HIGH
T0
T1
T2
COMMAND
WRITE
NOP
WRITE
ADDRESS
BANK,
COL n
CS#
CLK
RAS#
CAS#
WE#
A0-A7
BANK,
COL b
COLUMN
ADDRESS
DQ
A8-A9
DIN
n
DIN
n+1
DIN
b
ENABLE AUTO PRECHARGE
A10
NOTE:
DISABLE AUTO PRECHARGE
DQM is LOW. Each WRITE
command may be to any bank.
BANK 1
BA
DON’T CARE
BANK 0
Figure 13
WRITE Command
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
Figure 15
WRITE to WRITE
19
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©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
issued tWR after the clock edge at which the last desired
input data element is registered. 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 fixedlength 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.
random write accesses within a page can be performed
as shown in Figure 16.
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
T0
T1
T2
T3
WRITE
WRITE
WRITE
WRITE
CLK
COMMAND
T0
T1
T2
T3
T4
T5
NOP
ACTIVE
CLK
tWR = 1 CLK (tCK tWR)
BANK,
COL n
ADDRESS
BANK,
COL a
BANK,
COL x
BANK,
COL m
DQM
t RP
DIN
n
DQ
NOTE:
COMMAND
DIN
m
DIN
x
DIN
a
ADDRESS
Each WRITE command may be to any bank.
DQM is LOW.
DQ
T1
T2
T3
T4
NOP
NOP
PRECHARGE
BANK
(a or all)
BANK a,
COL n
BANK a,
ROW
t WR
Figure 16
Random WRITE Cycles
T0
WRITE
DIN
n
DIN
n+1
tWR = 2 CLK (tCK < tWR)
DQM
T5
CLK
t RP
COMMAND
COMMAND
WRITE
NOP
READ
NOP
NOP
ADDRESS
ADDRESS
DQ
NOTE:
BANK,
COL n
DIN
n
NOP
NOP
PRECHARGE
NOP
BANK
(a or all)
BANK a,
COL n
DQ
DOUT
b
DOUT
b+1
NOTE:
DIN
n
BANK a,
ROW
DIN
n+1
DQM could remain LOW in this example if the WRITE burst is a
fixed length of two. Future SDRAMs will require a tWR of at least
two clocks.
The WRITE command may be to any bank, and the READ command may
be to any bank. DQM is LOW. CAS latency = 2 for illustration.
DON’T CARE
Figure 17
WRITE to READ
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
ACTIVE
t WR
BANK,
COL b
DIN
n+1
WRITE
NOP
Figure 18
WRITE to PRECHARGE
20
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©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
PRECHARGE
The PRECHARGE command is used to deactivate
the open row in a particular bank or the open row in
all banks (see Figure 20). 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, input BA selects the bank. When all
banks are to be precharged, input BA is 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.
T0
T1
T2
COMMAND
WRITE
BURST
TERMINATE
Next
Command
ADDRESS
BANK,
COL n
(Address)
DIN
n
(Data)
CLK
DQ
POWER-DOWN
POWER-DOWN occurs if CKE is registered LOW
coincident with a NOP or COMMAND INHIBIT, when
no accesses are in progress (see Figure 21). If POWERDOWN 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 either 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 powerdown 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).
NOTE: DQMs are low
Figure 19
Terminating a WRITE Burst
CLK
CKE
HIGH
CS#
((
))
((
))
CLK
tCKS
RAS#
CKE
((
))
COMMAND
CAS#
< tCKS
((
))
((
))
NOP
NOP
tRCD
tRAS
All banks idle
Input buffers gated off
WE#
Enter POWERDOWN mode
ACTIVE
Exit POWERDOWN mode
A0-A9
tRC
DON’T CARE
Figure 21
POWER-DOWN
BANK 0 and 1
A10
BANK 0 or 1
BANK 1
BA
BANK 0
Figure 20
PRECHARGE Command
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
21
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: 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 are
ignored; any data present on the DQ pins will remain
driven; and burst counters are not incremented as long
as the clock is suspended (see examples in Figures 22
and 23).
T0
T1
T2
T3
T4
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).
T5
T0
CLK
CLK
CKE
CKE
T2
T3
T4
T5
T6
INTERNAL
CLOCK
INTERNAL
CLOCK
COMMAND
T1
NOP
ADDRESS
WRITE
NOP
COMMAND
READ
ADDRESS
BANK,
COL n
DIN
n
DIN
n+1
DIN
n+2
NOP
NOP
NOP
DOUT
n
DOUT
n+1
DOUT
n+2
DOUT
n+3
NOTE: For this example, CAS latency = 2, burst length = 4 or greater, and
DQM is LOW.
NOTE: For this example, burst length = 4 or greater, and DQM
is LOW.
DON’T CARE
Figure 22
Clock Suspend During WRITE Burst
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
NOP
BANK,
COL n
DQ
DQ
NOP
NOP
Figure 23
Clock Suspend During READ Burst
22
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: 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.
PRECHARGE): A READ to bank m will interrupt a
READ 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
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.
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
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
DIN
d
DIN
d+1
DIN
d+2
DIN
d+3
CAS Latency = 3 (BANK n)
NOTE: 1. DQM is HIGH at T2 to prevent DOUT-a+1 from contending with DIN-d at T4.
DON’T CARE
Figure 25
READ with AUTO PRECHARGE Interrupted by a WRITE
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
23
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: 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 dataout 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).
T0
T1
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).
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)
NOTE: 1. DQM is LOW.
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
NOP
NOP
WRITE with Burst of 4
WRITE - AP
BANK m
NOP
Interrupt Burst, Write-Back
tWR - BANK n
BANK m
ADDRESS
DQ
Page Active
NOP
Precharge
tRP - BANK n
t WR - BANK m
Write-Back
WRITE with Burst of 4
BANK n,
COL a
DIN
a
NOP
BANK m,
COL d
DIN
a+1
DIN
a+2
NOTE: 1. DQM is LOW.
DIN
d
DIN
d+1
DIN
d+2
DIN
d+3
DON’T CARE
Figure 27
WRITE with AUTO PRECHARGE Interrupted by a WRITE
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
24
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
TRUTH TABLE 2 – CKE
(Notes: 1-4)
CKEn-1 CKEn
L
L
L
H
H
L
H
H
CURRENT STATE
COMMAND n
ACTION n
Power-Down
X
Maintain Power-Down
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
7
Clock Suspend
X
Exit Clock Suspend
All Banks Idle
COMMAND INHIBIT or NOP
Power-Down Entry
All Banks Idle
AUTO REFRESH
Reading or Writing
VALID
NOTES
Self Refresh Entry
Clock Suspend Entry
See Truth Table 3
NOTE: 1.
2.
3.
4.
5.
CKEn is the logic state of CKE at clock edge n; CKEn-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.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
25
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: 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 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 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 occuring 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
t
RP has been met. Once tRP is met, the bank will be in the idle state.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
26
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: 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.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
27
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: 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#
Any
COMMAND (ACTION)
NOTES
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
Row Activating,
L
L
H
H
ACTIVE (Select and activate row)
Active or
L
H
L
H
READ (Select column and start READ burst)
7
Precharging
L
H
L
L
WRITE (Select column and start WRITE burst)
7
L
L
H
L
PRECHARGE
L
L
H
H
ACTIVE (Select and activate row)
Read
(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
L
L
H
L
PRECHARGE
Write
L
L
H
H
ACTIVE (Select and activate row)
(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
9
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
t
RP has been met. Once tRP is met, the bank will be in the idle state.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
28
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: 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).
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
29
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
ABSOLUTE MAXIMUM RATINGS*
*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.
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 (ambient) .. 0°C to +70°C
Storage Temperature (plastic) ........... -55°C to +150°C
Power Dissipation ................................................... 1W
DC ELECTRICAL CHARACTERISTICS AND OPERATING CONDITIONS
(Notes: 1, 6) (0°C ≤ TA ≤ 70°C; 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
OUTPUT LEAKAGE CURRENT: DQs are disabled; 0V ≤ VOUT ≤ VDDQ
IOZ
-10
10
µA
OUTPUT LEVELS:
Output High Voltage (IOUT = -4mA)
Output Low Voltage (IOUT = 4mA)
VOH
2.4
–
V
VOL
–
0.4
V
INPUT LEAKAGE CURRENT:
Any input 0V ≤ VIN ≤ VDD
(All other pins not under test = 0V)
UNITS NOTES
IDD SPECIFICATIONS AND CONDITIONS
(Notes: 1, 6, 11, 13) (0°C ≤ TA ≤ 70°C; VDD, VDDQ = +3.3V ±0.3V)
PARAMETER/CONDITION
MAX
SYMBOL
-6
-7
-8A
OPERATING CURRENT: Active Mode;
Burst = 2; READ or WRITE; tRC = tRC (MIN);
CAS latency = 3
IDD1
145
140
135
mA
3, 18,
19, 26
STANDBY CURRENT: Power-Down Mode;
CKE = LOW; All banks idle
IDD2
2
2
2
mA
26
STANDBY CURRENT: Active Mode; CS# = HIGH;
CKE = HIGH; All banks active after tRCD met;
No accesses in progress
IDD3
45
40
35
mA
3, 12,
19, 26
OPERATING CURRENT: Burst Mode; Continuous burst;
READ or WRITE; All banks active, CAS latency = 3
IDD4
140
130
100
mA
3, 18,
19, 26
AUTO REFRESH CURRENT: tRC = 15.625µs; CAS latency = 3;
CS# = HIGH; CKE = HIGH
IDD5
45
40
35
mA
3, 12,
18, 19,
26
SELF REFRESH CURRENT: CKE ≤ 0.2V
IDD6
1
1
1
mA
4
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
30
UNITS NOTES
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
CAPACITANCE
PARAMETER
SYMBOL
MIN
MAX
CI1
2.5
4.0
pF
2
Input Capacitance: All other input-only pins
CI2
2.5
5.0
pF
2
Input/Output Capacitance: DQs
CIO
4.0
6.5
pF
2
Input Capacitance: CLK
UNITS NOTES
ELECTRICAL CHARACTERISTICS AND RECOMMENDED AC OPERATING CONDITIONS
(Notes: 5, 6, 8, 9, 11) (0°C ≤ TA ≤ +70°C)
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
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
Data-out low-impedance time
Data-out hold time
ACTIVE to PRECHARGE command
AUTO REFRESH, ACTIVE command period
AUTO REFRESH period
ACTIVE to READ or WRITE delay
Refresh period - 2,048 or 4,096 rows
PRECHARGE command period
ACTIVE bank A to ACTIVE bank B command
Transition time
WRITE recovery time
Exit SELF REFRESH to ACTIVE command
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
CL = 3
CL = 2
CL = 1
CL = 3
CL = 2
CL = 1
CL = 3
CL = 2
CL = 1
-6
-7
-8A
SYMBOL MIN
MAX
MIN
MAX
MIN
MAX UNITS NOTES
tAC
5.5
5.5
6
ns
tAC
8
8.5
9
ns
22
tAC
18
22
22
ns
22
tAH
1
1
1
ns
tAS
2
2
2
ns
tCH
2.5
2.75
3
ns
tCL
2.5
2.75
3
ns
tCK
6
7
8
ns
23
tCK
8
10
13
ns
22, 23
tCK
20
25
25
ns
23
tCKH
1
1
1
ns
tCKS
2
2
2
ns
tCMH
1
1
1
ns
tCMS
2
2
2
ns
tDH
1
1
1
ns
tDS
2
2
2
ns
tHZ
5.5
5.5
6
ns
10
tHZ
8
8.5
9
ns
10
tHZ
18
22
22
ns
10
tLZ
1
1
1
ns
tOH
2
2
2.5
ns
tRAS
42
120,000
42
120,000
48
120,000
ns
tRC
60
70
80
ns
22
tRCAR
66
70
80
ns
tRCD
18
20
24
ns
22
tREF
64
64
64
ms
tRP
18
21
24
ns
22
tRRD
12
14
16
ns
tT
0.3
1.2
0.3
1.2
0.3
10
ns
7
tWR
tCK
1 + 4ns
1 + 3ns
1 + 2ns
24
10
10
10
ns
25
tXSR
80
80
80
ns
20
31
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
AC FUNCTIONAL CHARACTERISTICS
(Notes: 5, 6, 7, 8, 9, 11) (0°C ≤ TA ≤ +70°C)
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
CL = 3
CL = 2
CL = 1
Data-in to PRECHARGE
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
CL = 3
CL = 2
CL = 1
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
32
SYMBOL
tCCD
tCKED
tPED
tDQD
tDQM
tDQZ
tDWD
tDAL
tDAL
tDAL
tDPL
tBDL
tCDL
tRDL
tMRD
tROH
tROH
tROH
-6
1
1
1
0
0
2
0
5
4
3
2
0
1
1
2
3
2
1
-7
1
1
1
0
0
2
0
5
4
3
2
0
1
1
2
3
2
1
-8A
1
1
1
0
0
2
0
5
4
3
2
0
1
1
2
3
2
1
UNITS
tCK
tCK
tCK
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
15, 21
15, 21
16
17
17
16, 21
26
17
17
17
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
NOTES
1.
2.
3.
4.
5.
6.
7.
8.
9.
All voltages referenced to VSS.
This parameter is sampled. VDD, VDDQ = +3.3V; f = 1
MHz, tA = 25°C.
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) is ensured.
An initial pause of 100µs is required after power-up,
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 wakeups 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 1.4V with equivalent load:
12. Other input signals are allowed to transition no more
than once in any two-clock period and are otherwise at
valid VIH or VIL levels.
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 decrease as the CAS latency is
reduced. This is due to the fact that the maximum cycle
rate is slower as the CAS latency is reduced.
19. Address transitions average one transition every twoclock period.
20. CLK must be toggled a minimum of two times during this
period.
21. Based on tCK = 166 MHz for -6, 143 MHz for -7 and 125
MHz for -8A.
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. The pulse width cannot be
greater than one third of the cycle rate.
23. The clock frequency must remain constant 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.
25. Precharge mode only.
26. tCK = 6ns for -6, 7ns for -7, 8ns for -8A.
Q
30pF
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 = 2.8V with
timing referenced to 1.4V crossover point.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
33
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
INITIALIZE AND LOAD MODE REGISTER
T0
CLK
CKE
((
))
tCKS
T1
tCK
tCKH
((
))
((
))
Tn + 1
((
))
NOP
((
))
tCMS
PRECHARGE
((
))
((
))
To + 1
tCL
((
))
((
))
tCH
AUTO
REFRESH
((
))
NOP
NOP
((
))
((
))
NOP
NOP
((
))
AUTO
REFRESH
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
ADDRESS
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
DQ
High-Z
((
))
T=100µs
(MIN)
Tp + 2
Tp + 3
((
))
DQM1
BANK(S)
Tp + 1
((
))
((
))
((
))
((
))
((
))
tCMH
COMMAND
((
))
((
))
LOAD MODE
REGISTER
tAS
ACTIVE
NOP
tAH
BANK,
ROW
CODE
((
))
tRP
Power-up:
VDD and
CLK stable.
tRCAR
Precharge
all banks.
tRC
tMRD
Program Mode Register.2, 3
AUTO REFRESH
AUTO REFRESH
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAH
tAS
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
tCKH
MIN
1
2
2.5
-7
MAX
MIN
1
2
2.75
MAX
MIN
1
2
3
-8A
MAX
-6
UNITS
ns
ns
ns
2.5
6
8
20
2.75
7
10
25
3
8
13
25
ns
ns
ns
ns
1
1
1
ns
SYMBOL*
tCKS
tCMH
tCMS
tMRD
tRC
tRCAR
tRP
MIN
2
1
2
2
60
66
18
-7
MAX
MIN
2
1
2
2
70
70
21
MAX
MIN
2
1
2
2
80
80
24
-8A
MAX
UNITS
ns
ns
ns
tCK
ns
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1. DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
2. The Mode Register may be loaded prior to the AUTO REFRESH cycles if desired.
3. Outputs are guaranteed High-Z after command is issued.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
34
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
POWER-DOWN MODE 1
T0
T1
T2
tCK
CLK
tCH
tCKS
CKE
tCKS
tCKH
tCMS
tCMH
COMMAND
Tn + 1
((
))
((
))
tCL
Tn + 2
tCKS
((
))
PRECHARGE
NOP
((
))
((
))
NOP
NOP
ACTIVE
((
))
((
))
DQM2
tAS
ADDRESS
tAH
((
))
((
))
BANK(S)
High-Z
((
))
DQ
Two clock cycles
Precharge all
active banks.
BANK,
ROW
Input buffers gated off while in
power-down mode.
All banks idle.
All banks idle, enter
power-down mode.
Exit power-down mode.
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAH
MIN
-7
MAX
MIN
MAX
MIN
-8A
MAX
-6
UNITS
SYMBOL*
1
2
2.5
1
2
2.75
1
2
3
ns
ns
ns
tCK (1)
2.75
7
3
8
ns
ns
tCMH
tCK (3)
2.5
6
tCK (2)
8
10
13
ns
tAS
tCH
tCL
tCKH
tCKS
tCMS
MIN
-7
MAX
MIN
MAX
MIN
-8A
MAX
UNITS
20
1
25
1
25
1
ns
ns
2
1
2
2
1
2
2
1
2
ns
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1. Violating refresh requirements during power-down may result in loss of data.
2. DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
35
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
CLOCK SUSPEND MODE 1
T0
T1
T2
tCK
CLK
T3
T4
T5
T6
T7
T8
T9
tCL
tCH
tCKS tCKH
CKE
tCKS
tCKH
tCMS
tCMH
COMMAND
READ
NOP
NOP
NOP
NOP
NOP
WRITE
NOP
tCMS tCMH
DQM3
tAS
A0-A9
tAH
COLUMN m
(A0 - A7)2
tAS
tAH
tAS
tAH
COLUMN e
(A0 - A7)2
A10
BA
BANK
BANK
tAC
tOH
tAC
DOUT m
DQ
tHZ
tDS
DOUT m + 1
tDH
DIN e
DIN e + 1
tLZ
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAC (3)
tAC (2)
tAC (1)
tAH
tAS
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
tCKH
MIN
-7
MAX
5.5
8
18
MIN
MAX
5.5
8.5
22
MIN
-8A
MAX
6
9
22
-6
UNITS
ns
ns
ns
SYMBOL*
tCKS
tCMH
tCMS
1
2
1
2
1
2
ns
ns
tDH
2.5
2.5
6
2.75
2.75
7
3
3
8
ns
ns
ns
tHZ (3)
8
20
10
25
13
25
ns
ns
tLZ
1
1
1
ns
tDS
MIN
2
1
2
1
2
MIN
2
1
2
tHZ (1)
1
2
MAX
1
2
5.5
8
18
tHZ (2)
tOH
-7
MAX
MIN
2
1
2
1
2
5.5
8.5
22
1
2
-8A
MAX
ns
ns
6
9
22
1
2.5
UNITS
ns
ns
ns
ns
ns
ns
ns
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. A8 and A9 = “Don’t Care.”
3. DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
36
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
AUTO REFRESH MODE
T0
CLK
T1
T2
tCK
tCH
tCKS
tCKH
tCMS
tCMH
PRECHARGE
AUTO
REFRESH
NOP
NOP
DQM1
tAS
ADDRESS
DQ
To + 1
((
))
((
))
tCL
((
))
CKE
COMMAND
Tn + 1
((
))
((
))
((
))
((
))
( ( NOP
))
AUTO
REFRESH
NOP
((
))
( ( NOP
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
ACTIVE
tAH
BANK(S)
High-Z
tRP
tRCAR
BANK,
ROW
tRC
Precharge all
active banks.
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAH
tAS
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
MIN
1
2
-7
MAX
MIN
1
2
MAX
MIN
1
2
-8A
MAX
-6
UNITS
ns
ns
SYMBOL*
tCKH
tCKS
2.5
2.5
2.75
2.75
3
3
ns
ns
tCMH
6
8
20
7
10
25
8
13
25
ns
ns
ns
tRC
tCMS
tRCAR
tRP
MIN
1
2
-7
MAX
MIN
1
2
MAX
MIN
1
2
-8A
MAX
UNITS
ns
ns
1
2
1
2
1
2
ns
ns
60
66
18
70
70
21
80
80
24
ns
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1. DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
37
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
SELF REFRESH MODE
T0
T1
CLK
tCK
tCL
tCH
T2
tCKS
> tRAS
CKE
tCKS
Tn + 1
((
))
((
))
((
))
((
))
((
))
tCKH
To + 1
((
))
((
))
To + 2
tCKS
tCMS tCMH
COMMAND
PRECHARGE
((
))
((
))
AUTO
REFRESH
NOP
DQM1
tAS
ADDRESS
AUTO
REFRESH
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
((
))
tAH
BANK(S)
High-Z
DQ
((
))
NOP ( (
((
))
((
))
tRP
tXSR
Precharge all
active banks.
Enter self
refresh mode.
Exit self refresh mode.
(Restart refresh time base.)
CLK stable prior to exiting
self refresh mode.
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAH
tAS
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
MIN
-7
MAX
MIN
MAX
MIN
-8A
MAX
-6
UNITS
SYMBOL*
1
2
1
2
1
2
ns
ns
tCKH
2.5
2.5
6
2.75
2.75
7
3
3
8
ns
ns
ns
tCMH
8
20
10
25
13
25
ns
ns
tRP
tCKS
tCMS
tRAS
tXSR
MIN
-7
MAX
MIN
MAX
MIN
-8A
MAX
UNITS
1
2
1
2
1
2
ns
ns
1
2
42
1
2
42
1
2
48
ns
ns
ns
18
80
120,000
21
80
120,000
24
80
120,000
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1. DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
38
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
SINGLE READ – WITHOUT AUTO PRECHARGE 1
T0
T1
T2
tCK
CLK
T3
T4
T5
NOP
NOP
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
tAH
COLUMN m2
ROW
tAS
ROW
tAH
ALL BANKS
ROW
A10
tAS
BA0, BA1
ROW
tAH
DISABLE AUTO PRECHARGE
SINGLE BANKS
BANK
BANK(S)
BANK
tAC
tOH
tAC
DQ
DOUT m
tLZ
tRCD
BANK
tAC
tAC
tOH
DOUT m+1
tOH
tOH
DOUT m+2
DOUT m+3
tHZ
tRP
CAS Latency
tRAS
tRC
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAC (3)
tAC (2)
tAC (1)
tAH
tAS
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
tCKH
tCKS
MIN
-7
MAX
5.5
8
18
MIN
-8A
MAX
5.5
8.5
22
MIN
MAX
6
9
22
-6
UNITS
ns
ns
ns
SYMBOL*
tCMH
tCMS
tHZ (3)
1
2
1
2
1
2
ns
ns
tHZ (2)
2.5
2.5
6
2.75
2.75
7
3
3
8
ns
ns
ns
tLZ
8
20
10
25
13
25
ns
ns
tRC
1
2
1
2
1
2
ns
ns
MIN
1
2
tHZ (1)
tOH
tRAS
1
2
42
-7
MAX
5.5
5.5
6
8
18
8.5
22
9
22
ns
ns
120,000
ns
ns
ns
1
2
42
MAX
120,000
MIN
1
2
-8A
MAX
UNITS
ns
ns
ns
120,000
MIN
1
2
1
2.5
48
tRCD
60
18
70
20
80
24
ns
ns
tRP
18
21
24
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. A8, A9 = “Don’t Care.”
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
39
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
READ – WITHOUT AUTO PRECHARGE 1
T0
T1
T2
tCK
CLK
T3
T4
T5
NOP
NOP
T6
T7
T8
NOP
ACTIVE
tCL
tCH
tCKS
tCKH
CKE
tCMS tCMH
COMMAND
ACTIVE
NOP
READ
NOP
PRECHARGE
tCMS tCMH
DQM3
tAS
A0-A9
tAH
tAS
ROW
tAH
BANK 0 and 1
ROW
A10
tAS
BA
COLUMN m
(A0 - A7)2
ROW
ROW
tAH
DISABLE AUTO PRECHARGE
BANK 0 or 1
BANK
BANK(S)
BANK
tAC
tOH
tAC
DQ
DOUT m
tLZ
tRCD
BANK
tAC
tAC
tOH
DOUT m+1
tOH
tOH
DOUT m+2
DOUT m+3
tHZ
tRP
CAS Latency
tRAS
tRC
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
MIN
tAC
(3)
tAC (2)
tAC (1)
tAH
-7
MAX
MIN
MIN
SYMBOL*
tCMH
1
1
2
2.5
2
2.75
2
3
ns
ns
tHZ (1)
2.5
6
8
2.75
7
10
3
8
13
ns
ns
ns
tOH
25
1
25
1
ns
ns
tRCD
tCKH
20
1
tCKS
2
2
2
ns
tCL
tCK (3)
tCK (2)
tCK (1)
6
9
22
-6
UNITS
1
tCH
5.5
8.5
22
-8A
MAX
ns
ns
ns
ns
tAS
5.5
8
18
MAX
tCMS
MIN
1
-7
MAX
2
MIN
1
MAX
2
MIN
1
-8A
MAX
2
tHZ (3)
5.5
5.5
6
tHZ (2)
8
18
8.5
22
9
22
tLZ
tRAS
tRC
tRP
1
1
1
2
42
2
42
2.5
48
60
18
18
120,000
70
20
21
120,000
80
24
24
120,000
UNITS
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
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. A8 and A9 = “Don’t Care.”
3. DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
40
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
READ – WITH AUTO PRECHARGE 1
T0
T1
T2
tCK
CLK
tCKS
T3
T4
T5
NOP
NOP
T6
T7
T8
NOP
ACTIVE
tCL
tCH
tCKH
CKE
tCMS tCMH
COMMAND
ACTIVE
NOP
READ
NOP
NOP
tCMS tCMH
DQM3
tAS
A0-A9
tAH
ROW
ENABLE AUTO PRECHARGE
ROW
tAS
BA
COLUMN m
(A0 - A7)2
ROW
tAS
A10
tAH
ROW
tAH
BANK
BANK
BANK
tAC
tOH
tAC
DQ
DOUT m
tLZ
tRCD
tAC
tOH
tAC
tOH
DOUT m + 1
tOH
DOUT m + 2
DOUTm + 3
tHZ
tRP
CAS Latency
tRAS
tRC
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAC (3)
tAC (2)
tAC
MIN
-7
MAX
5.5
8
MIN
MAX
5.5
8.5
MIN
-8A
MAX
6
9
-6
UNITS
ns
ns
SYMBOL*
ns
2
2
ns
ns
ns
tAS
2
2.5
2.5
2
2.75
2.75
2
3
3
ns
ns
ns
tHZ (1)
6
8
7
10
8
13
ns
ns
tRAS
20
1
2
25
1
2
25
1
2
ns
ns
ns
tRCD
tCK (3)
tCK (2)
tCK (1)
tCKH
tCKS
UNITS
2
tHZ (3)
tCL
-8A
MAX
tCMS
ns
ns
tCH
MIN
1
1
22
MAX
1
1
22
MIN
1
1
18
-7
MAX
tCMH
tAH
(1)
MIN
5.5
8
tHZ (2)
tLZ
tOH
tRC
tRP
5.5
8.5
18
1
2
42
60
18
18
22
1
120,000
6
9
2
42
70
20
21
22
1
120,000
2.5
48
80
24
24
120,000
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. A8 and A9 = “Don’t Care.”
3. DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
41
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
ALTERNATING BANK READ ACCESSES 1
T0
T1
T2
tCK
CLK
T3
T4
T5
NOP
ACTIVE
T6
T7
T8
READ
NOP
ACTIVE
tCL
tCH
tCKS
tCKH
CKE
tCMS tCMH
COMMAND
ACTIVE
NOP
READ
NOP
tCMS tCMH
DQM3
tAS
A0-A9
tAH
COLUMN b
(A0 - A7)2
ROW
ENABLE AUTO PRECHARGE
ROW
ENABLE AUTO PRECHARGE
ROW
tAS
BA
COLUMN m
(A0 - A7)2
ROW
tAS
A10
tAH
ROW
ROW
tAH
BANK 0
BANK 0
BANK 1
tAC
tOH
tAC
DQ
DOUT m
tLZ
tRCD - BANK 0
BANK 1
tAC
tOH
BANK 0
tAC
tOH
DOUT m + 1
tAC
tOH
DOUT m + 2
tAC
tOH
DOUT m + 3
DOUT b
tRP - BANK 0
CAS Latency - BANK 0
tRCD - BANK 0
tRAS - BANK 0
tRC - BANK 0
tRCD - BANK 1
tRRD
CAS Latency - BANK 1
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAC (3)
tAC
tAC
MIN
(2)
(1)
tAH
tAS
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
tCKH
-7
MAX
5.5
MIN
8
18
MAX
5.5
MIN
8.5
22
-8A
MAX
6
9
22
-6
UNITS
ns
SYMBOL*
tCKS
ns
ns
tCMH
tCMS
1
2
2.5
1
2
2.75
1
2
3
ns
ns
ns
tLZ
2.5
6
2.75
7
3
8
ns
ns
tRC
8
20
1
10
25
1
13
25
1
ns
ns
ns
tRP
tOH
tRAS
tRCD
tRRD
MIN
2
-7
MAX
MIN
2
MAX
MIN
2
-8A
MAX
UNITS
ns
1
2
1
2
1
2
ns
ns
1
2
42
1
2
42
1
2.5
48
ns
ns
ns
120,000
120,000
120,000
60
18
70
20
80
24
ns
ns
18
12
21
14
24
16
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 4, and the CAS latency = 2.
2. A8 and A9 = “Don’t Care.”
3. DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
42
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
READ – FULL-PAGE BURST 1
T0
T1
T2
tCL
CLK
T3
T4
T5
T6
tCH
tCKS
Tn + 1
((
))
((
))
tCK
Tn + 2
Tn + 3
Tn + 4
tCKH
((
))
((
))
CKE
tCMS
COMMAND
tCMH
ACTIVE
NOP
READ
tCMS
NOP
NOP
NOP
NOP
tCMH
A0-A9
tAH
tAS
tAH
tAS
BA
NOP
NOP
((
))
((
))
ROW
A10
BURST TERM
((
))
((
))
COLUMN m
(A0 - A7)2
ROW
NOP
((
))
((
))
DQM3
tAS
((
))
((
))
tAH
BANK
((
))
((
))
BANK
tAC
tAC
tOH
DOUT m
DQ
tAC
tOH
DOUT m+1
tLZ
tAC ( (
tOH ) )
tAC
tAC
tOH
((
))
DOUT m+2
((
))
tOH
DOUT m-1
tOH
DOUT m
DOUT m+1
tHZ
256 locations within same row.
Full page completed.
tRCD
Full-page burst does not self-terminate.
Can use BURST TERMINATE command. 4
CAS Latency
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
MIN
tAC
(3)
tAC (2)
tAC (1)
tAH
tAS
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
-7
MAX
MIN
5.5
8
18
MAX
MIN
5.5
8.5
22
-8A
MAX
6
9
22
-6
SYMBOL*
tCKH
tCKS
UNITS
ns
ns
ns
tCMH
1
2
1
2
1
2
ns
ns
tCMS
2.5
2.5
6
2.75
2.75
7
3
3
8
ns
ns
ns
tHZ (2)
8
20
10
25
13
25
ns
ns
tOH
MIN
1
2
1
2
tHZ (3)
tRCD
MIN
1
2
-8A
MAX
1
2
5.5
8
18
tHZ (1)
tLZ
-7
MAX
MIN
1
2
MAX
1
2
5.5
8.5
22
UNITS
ns
ns
ns
ns
6
9
22
ns
ns
ns
1
2
1
2
1
2.5
ns
ns
18
20
24
ns
*CAS latency indicated in parentheses.
NOTE: 1.
2.
3.
4.
For this example, the CAS latency = 2.
A8 and A9 = “Don’t Care.”
DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
Page left open; no tRP.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
43
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
READ – DQM OPERATION 1
T0
T1
T2
tCK
CLK
tCKS
tCKH
tCMS
tCMH
T3
T4
T5
NOP
NOP
T6
T7
T8
NOP
NOP
NOP
tCL
tCH
CKE
COMMAND
ACTIVE
NOP
READ
tCMS
NOP
tCMH
DQM3
tAS
A0-A9
tAH
tAS
A10
tAH
ENABLE AUTO PRECHARGE
ROW
tAS
BA
COLUMN m
(A0 - A7)3
ROW
DISABLE AUTO PRECHARGE
tAH
BANK
BANK
tAC
tOH
DQ
tAC
tOH
tAC
DOUT m
tLZ
tRCD
tHZ
tOH
DOUT m + 2
DOUT m + 3
tLZ
tHZ
CAS Latency
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAC (3)
MIN
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
MAX
5.5
MIN
-8A
MAX
6
-6
SYMBOL*
UNITS
ns
tCKH
MIN
tCMH
1
2
2.5
1
2
2.75
1
2
3
ns
ns
ns
tCMS
2
2.5
6
2.75
7
3
8
ns
ns
tHZ (1)
8
20
10
25
13
25
ns
ns
tOH
(2)
tAC (1)
tAS
MIN
1
2
1
tAC
tAH
-7
MAX
5.5
8
18
8.5
22
9
22
ns
ns
tCKS
-7
MAX
MIN
MAX
1
2
1
MIN
-8A
MAX
1
2
1
2
ns
ns
ns
2
tHZ (3)
5.5
5.5
6
tHZ (2)
8
18
8.5
22
9
22
tLZ
tRCD
UNITS
ns
ns
1
1
1
ns
ns
ns
2
18
2
20
2.5
24
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 4, and the CAS latency = 2.
2. A8 and A9 = “Don’t Care.”
3. DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
44
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
SINGLE WRITE – WITHOUT AUTO PRECHARGE 1
T0
tCK
CLK
T1
T2
tCL
T3
T4
T5
T6
tCH
tCKS
tCKH
tCMS
tCMH
CKE
COMMAND
ACTIVE
NOP
WRITE
NOP
PRECHARGE
NOP
ACTIVE
tCMS tCMH
DQM /
DQML, DQMH
tAS
A0-A9, A11
tAH
COLUMN m 3
ROW
tAS
ROW
tAH
ALL BANKS
ROW
A10
tAS
BA0, BA1
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
SYMBOL*
tAH
tAS
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
tCKH
tCKS
MIN
1
2
-7
MAX
MIN
1
2
MAX
MIN
1
2
-8A
MAX
-6
UNITS
ns
ns
SYMBOL*
tCMH
tCMS
2.5
2.5
2.75
2.75
3
3
ns
ns
tDH
6
8
20
7
10
25
8
13
25
ns
ns
ns
tRAS
1
2
1
2
1
2
ns
ns
tRP
tDS
tRC
tRCD
tWR
MIN
1
2
-7
MAX
1
2
42
60
18
18
10
MIN
1
2
MAX
1
2
120,000
42
70
20
21
10
MIN
1
2
-8A
MAX
1
2
120,000
48
80
24
24
10
UNITS
ns
ns
ns
ns
120,000
ns
ns
ns
ns
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. 10ns is required between <DIN m> and the PRECHARGE command, regardless of frequency, to meet tWR.
3. A8, A9 = “Don’t Care.”
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
45
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
WRITE – WITHOUT AUTO PRECHARGE 1
T0
tCK
CLK
tCKS
T1
T2
tCL
T3
T4
T5
T6
NOP
NOP
NOP
T7
T8
NOP
ACTIVE
tCH
tCKH
CKE
tCMS tCMH
COMMAND
ACTIVE
NOP
WRITE
PRECHARGE
tCMS tCMH
DQM3
tAS
A0-A9
ROW
tAH
BANK 0 and 1
ROW
tAS
BA
COLUMN m
(A0 - A7)2
ROW
tAS
A10
tAH
ROW
tAH
DISABLE AUTO PRECHARGE
BANK 0 or 1
BANK
BANK(S)
BANK
tDS
tDS
tDH
DIN m
DQ
tDH
DIN m + 1
tDS
tDH
DIN m + 2
tDS
BANK
tDH
DIN m + 3
tRCD
tRAS
tRP
t WR4
tRC
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAH
tAS
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
tCKH
tCKS
MIN
1
-7
MAX
MIN
1
-8A
MAX
MIN
1
MAX
-6
UNITS
ns
SYMBOL*
tCMH
2
2.5
2.5
2
2.75
2.75
2
3
3
ns
ns
ns
tCMS
6
8
7
10
8
13
ns
ns
tRAS
20
1
2
25
1
2
25
1
2
ns
ns
ns
tRCD
tDH
tDS
tRC
tRP
tWR
MIN
1
-7
MAX
2
1
2
42
60
18
18
10
MIN
1
-8A
MAX
2
1
2
120,000
42
70
20
21
10
MIN
1
MAX
2
1
2
120,000
48
80
24
24
10
UNITS
ns
ns
ns
ns
120,000
ns
ns
ns
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1.
2.
3.
4.
For this example, the burst length = 4, and the WRITE burst is followed by “manual” PRECHARGE.
A8 and A9 = “Don’t Care.”
DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
Faster frequencies will require two clocks (when tWR > tCK).
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
46
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
WRITE – WITH AUTO PRECHARGE 1
T0
tCK
CLK
tCKS
T1
T2
tCL
T3
T4
T5
T6
T7
T8
NOP
NOP
NOP
NOP
NOP
ACTIVE
tCH
tCKH
CKE
tCMS tCMH
COMMAND
ACTIVE
NOP
WRITE
tCMS tCMH
DQM3
tAS
A0-A9
tAH
ROW
ENABLE AUTO PRECHARGE
ROW
tAS
BA
COLUMN m
(A0 - A7)2
ROW
tAS
A10
tAH
ROW
tAH
BANK
BANK
tDS
tDH
DIN m
DQ
BANK
tDS
tDH
DIN m + 1
tDS
tDH
DIN m + 2
tDS
tDH
DIN m + 3
tRCD
tRAS
tRP
tWR4
tRC
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAH
tAS
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
tCKH
tCKS
MIN
1
2
-7
MAX
MIN
1
2
MAX
MIN
1
2
-8A
MAX
-6
UNITS
ns
ns
SYMBOL*
tCMH
tCMS
2.5
2.5
2.75
2.75
3
3
ns
ns
tDH
6
8
20
7
10
25
8
13
25
ns
ns
ns
tRAS
1
2
1
2
1
2
ns
ns
tRP
tDS
tRC
tRCD
tWR
MIN
1
-7
MAX
2
1
2
42
60
18
18
1 + 4ns
MIN
1
MAX
2
1
2
120,000
42
70
20
21
1 + 3ns
MIN
1
-8A
MAX
2
1
2
120,000
48
80
24
24
1 + 2ns
UNITS
ns
ns
ns
ns
120,000
ns
ns
ns
ns
tCK
*CAS latency indicated in parentheses.
NOTE: 1.
2.
3.
4.
For this example, the burst length = 4.
A8 and A9 = “Don’t Care.”
DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
Faster frequencies will require two clocks (when tWR > tCK).
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
47
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
ALTERNATING BANK WRITE ACCESSES 1
T0
tCK
CLK
T1
T2
tCL
T3
T4
T5
T6
T7
T8
NOP
ACTIVE
tCH
tCKS
tCKH
CKE
tCMS tCMH
COMMAND
ACTIVE
NOP
WRITE
NOP
ACTIVE
NOP
WRITE
tCMS tCMH
DQM3
tAS
A0-A9
tAH
COLUMN b
(A0 - A7)2
ROW
ENABLE AUTO PRECHARGE
ROW
ENABLE AUTO PRECHARGE
ROW
tAS
BA
COLUMN m
(A0 - A7)2
ROW
tAS
A10
tAH
ROW
ROW
tAH
BANK 0
BANK 0
tDS
DIN m
DQ
BANK 1
tDH
tDS
tDH
DIN m + 1
tDS
BANK 1
tDH
tDS
DIN m + 2
tDH
tDS
DIN m + 3
BANK 0
tDH
tDS
DIN b
tDS
DIN b + 1
tWR - BANK 04
tRCD - BANK 0
tDH
tDH
DIN b + 2
tRCD - BANK 0
tRP - BANK 0
tRAS - BANK 0
tRC - BANK 0
tRCD - BANK 1
tRRD
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAH
tAS
tCH
MIN
1
2
-7
MAX
MIN
1
2
MAX
MIN
1
2
-8A
MAX
-6
UNITS
ns
ns
SYMBOL*
tCMS
tDH
2.5
2.5
2.75
2.75
3
3
ns
ns
tDS
6
8
20
7
10
25
8
13
25
ns
ns
ns
tRC
1
2
1
2
ns
ns
tRRD
tCKS
1
2
tCMH
1
1
1
ns
tCL
tCK (3)
tCK (2)
tCK (1)
tCKH
tRAS
tRCD
tRP
tWR
MIN
-7
MAX
2
1
2
42
MIN
MAX
2
1
120,000
2
42
MIN
-8A
MAX
2
1
120,000
2
48
UNITS
ns
ns
120,000
ns
ns
60
18
18
70
20
21
80
24
24
ns
ns
ns
12
1 + 4ns
14
1 + 3ns
16
1 + 2ns
tCK
ns
*CAS latency indicated in parentheses.
NOTE: 1.
2.
3.
4.
For this example, the burst length = 4.
A8 and A9 = “Don’t Care.”
DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
Faster frequencies will require two clocks (when tWR > tCK).
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
48
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: 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
DQM
A0-A9
tAH
tAH
tAS
BA
BURST TERM
NOP
((
))
((
))
ROW
A10
NOP
((
))
((
))
COLUMN m
(A0 - A7)1
ROW
tAS
Tn + 3
((
))
((
))
2
tAS
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
tRCD
tDH
DIN m + 3
((
))
((
))
tDS
tDH
tDS
tDH
DIN m - 1
256 locations within
same row.
Full page completed.
Full-page burst does not
self-terminate. Can use
3
BURST TERMINATE command.
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAH
tAS
tCH
tCL
tCK (3)
tCK (2)
tCK (1)
MIN
-7
MAX
MIN
MAX
MIN
-8A
MAX
-6
UNITS
SYMBOL*
1
2
2.5
1
2
2.75
1
2
3
ns
ns
ns
tCKH
2.5
6
2.75
7
3
8
ns
ns
tCMS
8
20
10
25
13
25
ns
ns
tDS
tCKS
tCMH
tDH
tRCD
MIN
-7
MAX
MIN
MAX
MIN
-8A
MAX
UNITS
1
2
1
1
2
1
1
2
1
ns
ns
ns
2
1
2
1
2
1
ns
ns
2
18
2
20
2
24
ns
ns
*CAS latency indicated in parentheses.
NOTE: 1. A8 and A9 = “Don’t Care.”
2. DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
3. Page left open; no tRP.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
49
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
WRITE – DQM OPERATION 1
T0
T1
T2
tCK
CLK
T3
T4
T5
NOP
NOP
NOP
T6
T7
NOP
NOP
tCL
tCH
tCKS
tCKH
CKE
tCMS tCMH
COMMAND
ACTIVE
NOP
WRITE
tCMS tCMH
3
DQM
tAS
A0-A9
tAH
COLUMN m
(A0 - A7)2
ROW
tAS
tAH
ENABLE AUTO PRECHARGE
ROW
A10
tAS
BA
tAH
DISABLE AUTO PRECHARGE
BANK
BANK
tDS
tDH
tDS
DIN m
DQ
tDH
tDS
DIN m + 2
tDH
DIN m + 3
tRCD
DON’T CARE
UNDEFINED
TIMING PARAMETERS
-6
SYMBOL*
tAH
tAS
MIN
1
-7
MAX
MIN
1
-8A
MAX
MIN
1
MAX
-6
UNITS
ns
SYMBOL*
tCKH
2
2.5
2.5
2
2.75
2.75
2
3
3
ns
ns
ns
tCKS
6
8
7
10
8
13
ns
ns
tDH
tCK (2)
tCK (1)
20
25
25
ns
tRCD
tCH
tCL
tCK (3)
tCMH
tCMS
tDS
MIN
1
-7
MAX
MIN
1
-8A
MAX
MIN
1
MAX
UNITS
ns
2
1
2
2
1
2
2
1
2
ns
ns
ns
1
2
1
2
1
2
ns
ns
18
20
24
ns
*CAS latency indicated in parentheses.
NOTE: 1. For this example, the burst length = 4.
2. A8 and A9 = “Don’t Care.”
3. DQM represents DQML and DQMH. DQML controls the lower byte, and DQMH controls the upper byte.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
50
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.
16Mb: x16
SDRAM
50-PIN PLASTIC TSOP (400 mil)
C-4
21.04
20.88
0.88
0.10 (2X)
50
2.80
11.86
11.66
10.21
10.11
1
SEE DETAIL A
25
PIN #1 ID
0.80
TYP
0.18
0.13
0.45
0.30
R 0.75 (2X)
0.25
R 1.00 (2X)
0.25
0.05
GAGE PLANE
0.10
1.2
MAX
0.60
0.40
DETAIL A
0.80
TYP
NOTE: 1. All dimensions in millimeters MAX or typical where noted.
MIN
2. Package width and length do not include mold protrusion; allowable mold protrusion is 0.01" per side.
8000 S. Federal Way, P.O. Box 6, Boise, ID 83707-0006, Tel: 208-368-3900
E-mail: [email protected], Internet: http://www.micronsemi.com, Customer Comment Line: 800-932-4992
Micron is a registered trademark of Micron Technology, Inc.
16Mb: x16 SDRAM
16MSDRAMx16.p65 – Rev. 8/99
51
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©1999, Micron Technology, Inc.