WINBOND W948D2FB

W948D6FB / W948D2FB
256Mb Mobile LPDDR
TABLE OF CONTENTS
1. GENERAL DESCRIPTION .................................................................................................. 4
2. FEATURES.......................................................................................................................... 4
3. PIN CONFIGURATION ........................................................................................................ 5
3.1 Ball Assignment: LPDDR x16 ...................................................................................................5
3.2 Ball Assignment: LPDDR x32 ...................................................................................................5
4. PIN DESCRIPTION ............................................................................................................. 6
4.1 Signal Descriptions ...................................................................................................................6
4.2 Addressing Table ......................................................................................................................7
5. BLOCK DIAGRAM .............................................................................................................. 8
5.1 Block Diagram ..........................................................................................................................8
5.2 Simplified State Diagram ..........................................................................................................9
6. FUNCTION DESCRIPTION ............................................................................................... 10
6.1 Initialization .............................................................................................................................10
6.1.1 Initialization Flow Diagram ............................................................................................................. 11
6.1.2 Initialization Waveform Sequence ................................................................................................. 12
6.2 Register Definition ..................................................................................................................12
6.2.1 Mode Register Set Operation ........................................................................................................ 12
6.2.2 Mode Register Definition ............................................................................................................... 13
6.2.3. Burst Length ................................................................................................................................. 13
6.3 Burst Definition .......................................................................................................................14
6.4 Burst Type ..............................................................................................................................15
6.5 Read Latency .........................................................................................................................15
6.6 Extended Mode Register Description ......................................................................................15
6.6.1 Extended Mode Register Definition ............................................................................................... 16
6.7 Status Register Read ..............................................................................................................16
6.7.1 SRR Register (A[n:0] = 0) .............................................................................................................. 17
6.7.2 Status Register Read Timing Diagram .......................................................................................... 18
6.8 Partial Array Self Refresh .......................................................................................................19
6.9 Automatic Temperature Compensated Self Refresh ...............................................................19
6.10 Output Drive Strength ...........................................................................................................19
6.11 Commands ...........................................................................................................................19
6.11.1 Basic Timing Parameters for Commands .................................................................................... 19
6.11.2 Truth Table - Commands ............................................................................................................. 20
6.11.3 Truth Table - DM Operations ....................................................................................................... 21
6.11.4 Truth Table - CKE ........................................................................................................................ 21
6.11.5 Truth Table - Current State BANKn - Command to BANKn ........................................................ 22
6.11.6 Truth Table - Current State BANKn, Command to BANKn ......................................................... 23
7. OPERATION...................................................................................................................... 24
7.1. Deselect.................................................................................................................................24
7.2. No Operation .........................................................................................................................24
7.2.1 NOP Command ............................................................................................................................. 25
7.3 Mode Register Set ..................................................................................................................25
-1-
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
7.3.1 Mode Register Set Command ....................................................................................................... 25
7.3.2 Mode Register Set Command Timing ........................................................................................... 26
7.4. Active .....................................................................................................................................26
7.4.1 Active Command ........................................................................................................................... 26
7.4.2 Bank Activation Command Cycle .................................................................................................. 27
7.5. Read ......................................................................................................................................27
7.5.1 Read Command ............................................................................................................................. 28
7.5.2 Basic Read Timing Parameters ..................................................................................................... 28
7.5.3 Read Burst Showing CAS Latency ................................................................................................ 29
7.5.4 Read to Read ................................................................................................................................. 29
7.5.5 Consecutive Read Bursts .............................................................................................................. 30
7.5.6 Non-Consecutive Read Bursts ...................................................................................................... 30
7.5.7 Random Read Bursts .................................................................................................................... 31
7.5.8 Read Burst Terminate.................................................................................................................... 31
7.5.9 Read to Write ................................................................................................................................. 32
7.5.10 Read to Pre-charge ..................................................................................................................... 32
7.6 Write .......................................................................................................................................33
7.6.1 Write Command ............................................................................................................................. 34
7.6.2 Basic Write Timing Parameters ..................................................................................................... 34
7.6.3 Write Burst (min. and max. tDQSS) ............................................................................................... 35
7.6.4 Write to Write ................................................................................................................................. 35
7.6.5 Concatenated Write Bursts ............................................................................................................ 36
7.6.6 Non-Consecutive Write Bursts ...................................................................................................... 36
7.6.7 Random Write Cycles .................................................................................................................... 37
7.6.8 Write to Read ................................................................................................................................. 37
7.6.9 Non-Interrupting Write to Read ...................................................................................................... 37
7.6.10 Interrupting Write to Read ........................................................................................................... 38
7.6.11 Write to Precharge ....................................................................................................................... 38
7.6.12 Non-Interrupting Write to Precharge ............................................................................................ 38
7.6.13 Interrupting Write to Precharge ................................................................................................... 39
7.7 Precharge ...............................................................................................................................39
7.7.1 Precharge Command..................................................................................................................... 40
7.8 Auto Precharge .......................................................................................................................40
7.9 Refresh Requirements ............................................................................................................40
7.10 Auto Refresh .........................................................................................................................40
7.10.1 Auto Refresh Command .............................................................................................................. 41
7.11 Self Referesh ........................................................................................................................41
7.11.1 Self Refresh Command ............................................................................................................... 42
7.11.2 Auto Refresh Cycles Back-to-Back ............................................................................................. 42
7.11.3 Self Refresh Entry and Exit ......................................................................................................... 43
7.12 Power Down .........................................................................................................................43
7.13 Deep Power Down ................................................................................................................44
7.13.1 Deep Power-Down Entry and Exit ............................................................................................... 44
7.14 Clock Stop ............................................................................................................................45
7.14.1 Clock Stop Mode Entry and Exit .................................................................................................. 45
-2-
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
8. ELECTRICAL CHARACTERISTIC ................................................................................... 46
8.1 Absolute Maximum Ratings ....................................................................................................46
8.2 Input/Output Capacitance .......................................................................................................46
8.3 Electrical Characteristics and AC/DC Operating Conditions ....................................................47
8.3.1 Electrical Characteristics and AC/DC Operating Conditions ......................................................... 47
8.4 IDD Specification Parameters and Test Conditions .................................................................48
8.4.1 IDD Specification Parameters and Test Conditions ...................................................................... 48
8.5 AC Timings .............................................................................................................................51
8.5.1 CAS Latency Definition (With CL=3) ............................................................................................. 54
8.5.2 Output Slew Rate Characteristics .................................................................................................. 55
8.5.3 AC Overshoot/Undershoot Specification ....................................................................................... 55
8.5.4 AC Overshoot and Undershoot Definition ..................................................................................... 55
9. PACKAGE DIMENSIONS ................................................................................................. 56
9.1: LPDDR X 16 ..........................................................................................................................56
9.2: LPDDR X 32 ..........................................................................................................................57
10. ORDERING INFORMATION ........................................................................................... 58
11. REVISION HISTORY ....................................................................................................... 59
-3-
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
1. GENERAL DESCRIPTION
W948D6FB / W948D2FB is a high-speed mobile double data rate synchronous dynamic random access memory
(LPDDR SDRAM), Using pipelined architecture , An access to the LPDDR SDRAM is burst oriented. Consecutive
memory location in one page can be accessed at a burst length of 2, 4, 8 and 16 when a bank and row is selected by
an ACTIVE command. Column addresses are automatically generated by the LPDDR SDRAM internal counter in
burst operation. Random column read is also possible by providing its address at each clock cycle. The multiple
bank nature enables interleaving among internal banks to hide the pre-charging time. By setting programmable
Mode Registers, the system can change burst length, latency cycle, interleave or sequential burst to maximize its
performance. The device supports special power saving functions such as Partial Array Self Refresh (PASR) and
Automatic Temperature Compensated Self Refresh (ATCSR).
2. FEATURES
VDD = 1.7~1.95V
VDDQ = 1.7~1.95V
Data width: x16 / x32
Clock rate: 200MHz(-5),166MHz (-6), 133MHz (-75)
Partial Array Self-Refresh(PASR)
Auto Temperature Compensated Self-Refresh(ATCSR)
Power Down Mode
Deep Power Down Mode (DPD Mode)
Programmable output buffer driver strength
Four internal banks for concurrent operation
Data mask (DM) for write data
Clock Stop capability during idle periods
Auto Pre-charge option for each burst access
Double data rate for data output
CAS Latency: 2 and 3
Burst Length: 2, 4, 8 and 16
Burst Type: Sequential or Interleave
64 ms Refresh period
Interface: LVCMOS
Support package:
60 balls VFBGA (x16)
90 balls VFBGA (x32)
Operating Temperature Range
Extended (-25℃ to + 85 ℃)
Industrial (-40℃ to + 85 ℃)
Differential clock inputs (CK and CK )
Bidirectional, data strobe (DQS)
-4-
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
3. PIN CONFIGURATION
3.1 Ball Assignment: LPDDR x16
60 BALL VFBGA
1
2
3
A
VSS
DQ15
B
VDDQ
C
4
5
6
7
8
9
VSSQ
VDDQ
DQ0
VDD
DQ13
DQ14
DQ1
DQ2
VSSQ
VSSQ
DQ11
DQ12
DQ3
DQ4
VDDQ
D
VDDQ
DQ9
DQ10
DQ5
DQ6
VSSQ
E
VSSQ
UDQS
DQ8
DQ7
LDQS
VDDQ
F
VSS
UDM
NC
NC
LDM
VDD
G
CKE
CK
CK
WE
CAS
RAS
H
A9
A11
A12
CS
BA0
BA1
J
A6
A7
A8
A10/AP
A0
A1
K
VSS
A4
A5
A2
A3
VDD
7
8
9
(Top View) Pin Configuration
3.2 Ball Assignment: LPDDR x32
90 BALL VFBGA
1
2
3
4
5
6
A
VSS
DQ31
VSSQ
VDDQ
DQ16
VDD
B
VDDQ
DQ29
DQ30
DQ17
DQ18
VSSQ
C
VSSQ
DQ27
DQ28
DQ19
DQ20
VDDQ
D
VDDQ
DQ25
DQ26
DQ21
DQ22
VSSQ
E
VSSQ
DQS3
DQ24
DQ23
DQS2
VDDQ
F
VDD
DM3
NC
NC
DM2
VSS
G
CKE
CK
CK
WE
CAS
RAS
H
A9
A11
NC
CS
BA0
BA1
J
A6
A7
A8
A10/AP
A0
A1
K
A4
DM1
A5
A2
DM0
A3
L
VSSQ
DQS1
DQ8
DQ7
DQS0
VDDQ
M
VDDQ
DQ9
DQ10
DQ5
DQ6
VSSQ
N
VSSQ
DQ11
DQ12
DQ3
DQ4
VDDQ
P
VDDQ
DQ13
DQ14
DQ1
DQ2
VSSQ
R
VSS
DQ15
VSSQ
VDDQ
DQ0
VDD
(Top View) Pin Configuration
-5-
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
4. PIN DESCRIPTION
4.1 Signal Descriptions
SIGNAL NAME
TYPE
FUNCTION
DESCRIPTION
Provide the row address for ACTIVE commands, and the column
address and AUTO PRECHARGE bit for READ/WRITE
commands, to select one location out of the memory array in the
respective bank. The address inputs also provide the opcode
during a MODE REGISTER SET command.
A10 is used for Auto Pre-charge Select.
A[n:0]
Input
Address
BA0, BA1
Input
Bank Select
Define to which bank an ACTIVE, READ, WRITE or
PRECHARGE command is being applied.
DQ0~DQ15 (×16)
DQ0~DQ31 (×32)
I/O
Data Input/
Output
Data bus: Input / Output.
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
CS
Input
command code.
RAS
Input
CAS
Input
WE
Input
UDM / LDM(x16);
Input
DM0 to DM3 (x32)
Row Address
Strobe
RAS , CAS and WE (along with CS ) define the command
being entered.
Column Address Referred to RAS
Strobe
Write Enable
Input Mask
Referred to RAS
Input Data Mask: DM is an input mask signal for write data. Input
data is masked when DM is sampled HIGH along with that input
data during a WRITE access. DM is sampled on both edges of
DQS. Although DM pins are input-only, the DM loading matches
the DQ and DQS loading.
x16: LDM: DQ0 - DQ7, UDM: DQ8 – DQ15
x32: DM0: DQ0 - DQ7, DM1: DQ8 – DQ15,
DM2: DQ16 – DQ23, DM3: DQ24 – DQ31
CK and CK are differential clock inputs. All address and control
input signals are sampled on the crossing of the positive edge of
CK / CK
Input
Clock Inputs
CK and negative edge of CK .Input and output data is
referenced to the crossing of CK and CK (both directions of
crossing). Internal clock signals are derived from CK/ CK .
-6-
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
SIGNAL NAME
TYPE
CKE
Input
FUNCTION
Clock Enable
DESCRIPTION
CKE HIGH activates, and CKE LOW deactivates internal clock
signals, and device input buffers and output drivers. Taking CKE
LOW provides PRECHARGE, POWER DOWN and SELF
REFRESH operation (all banks idle), or ACTIVE POWER DOWN
(row ACTIVE in any bank). CKE is synchronous for all functions
except for SELF REFRESH EXIT, which is achieved
LDQS, UDQS
(x16);
DQS0~DQS3
(x32)
I/O
Data Strobe
VDD
Supply
Power
asynchronously. Input buffers, excluding CK, CK and CKE, are
disabled during power down and self refresh mode which are
contrived for low standby power consumption.
Output with read data, input with write data. Edge-aligned with
read data, centered with write data. Used to capture write data.
x16: LDQS: DQ0~DQ7; UDQS: DQ8~DQ15.
x32: DQS0: DQ0~DQ7; DQS1: DQ8~DQ15;
DQS2: DQ16~DQ23; DQS3: DQ24~DQ31.
Power supply for input buffers and internal circuit.
VSS
Supply
Ground
Ground for input buffers and internal circuit.
VDDQ
Supply
Power for I/O
Buffer
Power supply separated from VDD, used for output drivers to
improve noise.
VSSQ
Supply
Ground for I/O
Buffer
Ground for output drivers.
NC
-
No Connect
No internal electrical connection is present.
4.2 Addressing Table
ITEM
256 Mb
Number of banks
4
Bank address pins
BA0,BA1
Auto precharge pin
A10/AP
X16
Row addresses
A0-A12
Column addresses
A0-A8
tREFI(µs)
x32
7.8
Row addresses
A0-A11
Column addresses
A0-A8
tREFI(µs)
15.6
-7-
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
5. BLOCK DIAGRAM
5.1 Block Diagram
CK
CK
CLOCK
BUFFER
CKE
CS
RAS
CAS
CONTROL
SIGNAL
GENERATOR
COMMAND
DECODER
COLUMN DECODER
WE
COLUMN DECODER
R
O
W
A10
MODE
REGISTER
A0
D
E
C
O
R
D
E
R
R
O
W
D
E
C
O
R
D
E
R
CELL ARRAY
BANK #0
CELL ARRAY
BANK #1
SENSE AMPLIFIER
SENSE AMPLIFIER
ADDRESS
An
BA0
BA1
BUFFER
DMn
DQ
BUFFER
DATA CONTROL
CIRCUIT
REFRESH
COUNTER
COLUMN
COUNTER
COLUMN DECODER
COLUMN DECODER
R
O
W
D
E
C
O
R
D
E
R
DQ0 – DQ15 (x16)
DQ0 – DQ31 (x32)
UDM / LDM (x16)
DMn (x32)
UDQS / LDQS (x16)
DQSn (x32)
R
O
W
CELL ARRAY
D
E
C
O
R
D
E
R
BANK #2
SENSE AMPLIFIER
CELL ARRAY
BANK #3
SENSE AMPLIFIER
-8-
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
5.2 Simplified State Diagram
Power
applied
Power
On
DPDSX
Self
Refresh
Deep
Power
Down
SRR
REFS
Read
Precharge
All Bank
Read
REFSX
SRR
DPDS
Idle
All banks
precharged
MRS
MRS
EMRS
Auto
Refresh
REFA
CKEL
CKEH
Precharge
Power
Down
ACT
Active
Power
Down
CKEH
CKEL
Row
Active
Burst
Stop
WRITE
READ
WRITE
WRITE
BST
READ
READA
WRITE
READ
READ
WRITEA
READA
WRITE A
PRE
PRE
PRE PRE
READA
READ A
Precharge
PREALL
Automatic Sequence
Command Sequence
ACT = Active
MRS = Ext . Mode Reg . Set
REFSX = Exit Self Refresh
BST = Burst Terminate
MRS = Mode Register Set
READ = Read w/o Auto Precharge
CKEL= Enter Power - Down
PRE = Precharge
READA = Read with Auto Precharge
CKEH=Exit Power - Down
PREALL = Precharge All Bank WRITE = Write w/o Auto Precharge
DPDS = Enter Deep Power
- Down
REFA = Auto Refresh
WRITEA = Write with Auto Precharge
DPDSX = Exit Deep Power
- Down
REFS = Enter Self Refresh
SRR = Status Register Read
Note: Use caution with this diagram . It is indented to provide a floorplan of the possible state transitions and commands to control them , not
all details .In particular situations involving more than one bank are not captured in full detall .
-9-
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6. FUNCTION DESCRIPTION
6.1 Initialization
LPDDR SDRAM must be powered up and initialized in a predefined manner. Operations procedures other than
those specified may result in undefined operation. If there is any interruption to the device power, the initialization
routine should be followed. The steps to be followed for device initialization are listed below.
The Mode Register and Extended Mode Register do not have default values. If they are not programmed during the
initialization sequence, it may lead to unspecified operation. The clock stop feature is not available until the device
has been properly initialized from Step 1 through 11.

Step 1: Provide power, the device core power (VDD) and the device I/O power (VDDQ) must be brought up
simultaneously to prevent device latch-up. Although not required, it is recommended that VDD and VDDQ
are from the same power source. Also Assert and hold Clock Enable (CKE) to a LVCMOS logic high level

Step 2: Once the system has established consistent device power and CKE is driven high, it is safe to apply
stable clock.

Step 3: There must be at least 200μs of valid clocks before any command may be given to the DRAM. During this
time NOP or DESELECT commands must be issued on the command bus.

Step 4: Issue a PRECHARGE ALL command.

Step 5: Provide NOPs or DESELECT commands for at least tRP time.

Step 6: Issue an AUTO REFRESH command followed by NOPs or DESELECT command for at least tRFC time.
Issue the second AUTO REFRESH command followed by NOPs or DESELECT command for at least
tRFC time. Note as part of the initialization sequence there must be two Auto Refresh commands issued.
The typical flow is to issue them at Step 6, but they may also be issued between steps 10 and 11.

Step 7: Using the MRS command, program the base mode register. Set the desired operation modes.

Step 8: Provide NOPs or DESELECT commands for at least tMRD time.

Step 9: Using the MRS command, program the extended mode register for the desired operating modes. Note the
order of the base and extended mode register programmed is not important.

Step 10: Provide NOP or DESELECT commands for at least tMRD time.

Step 11: The DRAM has been properly initialized and is ready for any valid command.
- 10 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6.1.1 Initialization Flow Diagram
1
VDD and VDDQ Ramp: CKE must be held high
2
Apply stable clocks
3
Wait at least 200us with NOP or DESELECT on command bus
4
PRECHARGE ALL
5
Assert NOP or DESELCT for
6
Issue two AUTO REFRESH commands each followed by
NOP or DESELECT commands for tRFC time
7
Configure Mode Register
8
Assert NOP or DESELECT for
9
Configure Extended Mode Register
tRP time
tMRD time
tMRD time
10
Assert NOP or DESELECT for
11
LPDDR SDRAM is ready for any valid command
- 11 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6.1.2 Initialization Waveform Sequence
VDD
VDDQ
200us
tCK
tRP
tRFC
tRFC
tMRD
tMRD
CK
CK
CKE
Command
NOP
PRE
ARF
Address
All
Banks
A10
ARF
MRS
MRS
ACT
CODE
CODE
RA
CODE
CODE
RA
BA0=L
BA1=L
BA0=L
BA1=H
Load
Mode Reg.
Load
Ext.Mode Reg..
BA0,BA1
BA
DM
DQ,DQS
(High-Z)
VDD/VDDQ powered up
Clock stable
= Don't Care
6.2 Register Definition
6.2.1 Mode Register Set Operation
The Mode Register is used to define the specific mode of operation of the LPDDR SDRAM. This definition includes
the definition of a burst length, a burst type, a CAS latency as shown in the following figure.
The Mode Register is programmed via the MODE REGISTER SET command (with BA0=0 and BA1=0) and will
retain the stored information until it is reprogrammed, the device goes into Deep Power Down mode, or the device
loses power.
Mode Register bits A0-A2 specify the burst length, A3 the type of burst (sequential or interleave), A4-A6 the CAS
latency. A logic 0 should be programmed to all the undefined addresses bits to ensure future compatibility.
The Mode Register must be loaded when all banks are idle and no bursts are in progress, and the controller must
wait the specified time tMRD before initiating any subsequent operation. Violating either of these requirements will
result in unspecified operation.
Reserved states should not be used, as unknown operation or incompatibility with future versions may result.
- 12 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6.2.2 Mode Register Definition
BA1
BA0
An..A7 (see Note 1)
0
0
0 (see Note 2)
A6
0
0
0
0
1
1
1
1
A5
0
0
1
1
0
0
1
1
A4
0
1
0
1
0
1
0
1
CAS Latency
Reserved
Reserved
2
3
Reserved
Reserved
Reserved
Reserved
A6
A5
A4
CAS Latency
A3
0
1
Burst Type
Sequential
Interleave
A3
A2
BT
A1
A0
Burst Length
A2
0
0
0
0
1
1
1
1
A1
0
0
1
1
0
0
1
1
A0
0
1
0
1
0
1
0
1
Address Bus
Mode Register
Burst Length
Reserved
2
4
8
16
Reserved
Reserved
Reserved
NOTE:
1.MSB depends on LPDDR SDRAM density.
2.Alogic 0 should be programmed to all unused / undefined address bits to future compatibility.
6.2.3. Burst Length
Read and write accesses to the LPDDR SDRAM are burst oriented, with the burst length and burst type being
programmable.
The burst length determines the maximum number of column locations that can be accessed for a given READ or
WRITE command. Burst lengths of 2, 4, or 8 locations are available for both the sequential and the interleaved burst
types.
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 the block, meaning that the burst will wrap within the block if a boundary is
reached.
The block is uniquely selected by A1−An when the burst length is set to two, by A2−An when the burst length is set
to 4, by A3−An when the burst length is set to 8 (where An is the most significant column address bit for a given
configuration). The remaining (least significant) address bit(s) is (are) used to select the starting location within the
block. The programmed burst length applies to both read and write bursts.
- 13 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6.3 Burst Definition
BURST
LENGTH
STARTING COLUMN
ADDRESS
A3
A2
A1
A0
SEQUENTIAL
INTERLEAVED
0
0–1
0–1
1
1–0
1–0
0
0
0–1–2–3
0–1–2–3
0
1
1–2–3–0
1–0–3–2
1
0
2–3–0–1
2–3–0–1
1
1
3–0–1–2
3–2–1–0
0
0
0
0–1–2–3–4–5–6–7
0–1–2–3–4–5–6–7
0
0
1
1–2–3–4–5–6–7–0
1–0–3–2–5–4–7–6
0
1
0
2–3–4–5–6–7–0–1
2–3–0–1–6–7–4–5
0
1
1
3–4–5–6–7–0–1–2
3–2–1–0–7–6–5–4
1
0
0
4–5–6–7–0–1–2–3
4–5–6–7–0–1–2–3
1
0
1
5–6–7–0–1–2–3–4
5–4–7–6–1–0–3–2
1
1
0
6–7–0–1–2–3–4–5
6–7–4–5–2–3–0–1
1
1
1
7–0–1–2–3–4–5–6
7–6–5–4–3–2–1–0
0
0
0
0
0-1-2-3-4-5-6-7-8-9-A-B-C-D-E-F 0-1-2-3-4-5-6-7-8-9-A-B-C-D-E-F
0
0
0
1
1-2-3-4-5-6-7-8-9-A-B-C-D-E-F-0 1-0-3-2-5-4-7-6-9-8-B-A-D-C-F-E
0
0
1
0
2-3-4-5-6-7-8-9-A-B-C-D-E-F-0-1 2-3-0-1-6-7-4-5-A-B-8-9-E-F-C-D
0
0
1
1
3-4-5-6-7-8-9-A-B-C-D-E-F-0-1-2 3-2-1-0-7-6-5-4-B-A-9-8-F-E-D-C
0
1
0
0
4-5-6-7-8-9-A-B-C-D-E-F-0-1-2-3 4-5-6-7-0-1-2-3-C-D-E-F-8-9-A-B
0
1
0
1
5-6-7-8-9-A-B-C-D-E-F-0-1-2-3-4 5-4-7-6-1-0-3-2-D-C-F-E-9-8-B-A
0
1
1
0
6-7-8-9-A-B-C-D-E-F-0-1-2-3-4-5 6-7-4-5-2-3-0-1-E-F-C-D-A-B-8-9
0
1
1
1
7-8-9-A-B-C-D-E-F-0-1-2-3-4-5-6 7-6-5-4-3-2-1-0-F-E-D-C-B-A-9-8
1
0
0
0
8-9-A-B-C-D-E-F-0-1-2-3-4-5-6-7 8-9-A-B-C-D-E-F-0-1-2-3-4-5-6-7
1
0
0
1
9-A-B-C-D-E-F-0-1-2-3-4-5-6-7-8 9-8-B-A-D-C-F-E-1-0-3-2-5-4-7-6
1
0
1
0
A-B-C-D-E-F-0-1-2-3-4-5-6-7-8-9 A-B-8-9-E-F-C-D-2-3-0-1-6-7-4-5
1
0
1
1
B-C-D-E-F-0-1-2-3-4-5-6-7-8-9-A B-A-9-8-F-E-D-C-3-2-1-0-7-6-5-4
1
1
0
0
C-D-E-F-0-1-2-3-4-5-6-7-8-9-A-B C-D-E-F-8-9-A-B-4-5-6-7-0-1-2-3
1
1
0
1
D-E-F-0-1-2-3-4-5-6-7-8-9-A-B-C D-C-F-E-9-8-B-A-5-4-7-6-1-0-3-2
1
1
1
0
E-F-0-1-2-3-4-5-6-7-8-9-A-B-C-D E-F-C-D-A-B-8-9-6-7-4-5-2-3-0-1
1
1
1
1
F-0-1-2-3-4-5-6-7-8-9-A-B-C-D-E F-E-D-C-B-A-9-8-7-6-5-4-3-2-1-0
2
4
8
16
ORDER OF ACCESSES WITHIN A BURST
(HEXADECIMAL NOTATION)
- 14 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
Notes:
1. For a burst length of two, A1-An selects the two data element block; A0 selects the first access within the block.
2. For a burst length of four, A2-An selects the four data element block; A0-A1 selects the first access within the block.
3. For a burst length of eight, A3-An selects the eight data element block; A0-A2 selects the first access within the block.
4. For the optional burst length of sixteen, A4-An selects the sixteen data element block; A0-A3 selects the first access within the
block.
5. Whenever a boundary of the block is reached within a given sequence, the following access wraps within the block.
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 the block, meaning that the burst will wrap within the block if a boundary is reached.
The block is uniquely selected by A1-An when the burst length is set to two, by A2-An when the burst length is set to 4, by A3An when the burst length is set to 8 and A4-An when the burst length is set to 16(where An is the most
significant column
address bit for a given configuration). The remaining (least significant) address bit(s) is (are) used to select the starting location
within the block. The programmed burst length applies to both read and write bursts.
6.4 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 A3. The ordering of accesses within a burst is determined by the burst length, the
burst type and the starting column address, as shown in the previous table.
6.5 Read Latency
The READ latency is the delay between the registration of a READ command and the availability of the first piece of
output data. The latency should be set to 2 or 3 clocks.
If a READ command is registered at a clock edge n and the latency is 3 clocks, the first data element will be valid at
n + 2 tCK + tAC. If a READ command is registered at a clock edge n and the latency is 2 clocks, the first data
element will be valid at n + tCK + tAC.
6.6 Extended Mode Register Description
The Extended Mode Register controls functions beyond those controlled by the Mode Register; these additional
functions include output drive strength selection and Partial Array Self Refresh (PASR). PASR is effective in Self
Refresh mode only.
The Extended Mode Register is programmed via the MODE REGISTER SET command (with BA1=1 and BA0=0)
and will retain the stored information until it is reprogrammed, the device is put in Deep Power Down mode, or the
device loses power.
The Extended Mode Register must be loaded when all banks are idle and no bursts are in progress, and the
controller must wait the specified time tMRD before initiating any subsequent operation. Violating either of these
requirements will result in unspecified operation.
Address bits A0-A2 specify PASR, A5-A7 the Driver Strength. A logic 0 should be programmed to all the undefined
addresses bits to ensure future compatibility.
Reserved states should not be used, as unknown operation or incompatibility with future versions may result.
- 15 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6.6.1 Extended Mode Register Definition
BA1
BA0
1
0
An....A8 (1)
A7 ~ A5
0 ( 2)
A6
A5
0
0
0
0
0
1
1
0
1
0
A3
A2
Reserved
DS
A7
A4
Drive Strength
A1
A0
Address Bus
PASR
Extended Mode Reg.
PASR
A2
A1
A0
0
0
0
All banks
Quarter Strength Driver
0
0
1
1/2 array (BA1=0)
Octant Strength Driver
0
1
0
1/4 array (BA1=BA0=0)
Three-Quarters Strength Driver
0
1
1
Reserved
1
0
0
Reserved
1
0
1
Reserved
1
1
0
Reserved
1
1
NOTES:
1.MSB depends on mobile DDR SDRAM density.
2.A logic 0 should be programmed to all unused / undefined bits to ensure future compatibility.
1
Reserved
0
1
0
1
0
Full Strength Driver
Half Strength Drive
6.7 Status Register Read
Status Register Read (SRR) is an optional feature in JEDEC, and it is implemented in this device. With SRR, a
method is defined to read registers from the device. The encoding for an SRR command is the same as a MRS with
BA[1:0]=”01”. The address pins (A[n:0]) encode which register is to be read. Currently only one register is defined at
A[n:0]=0. The sequence to perform an SRR command is as follows:







All reads/writes must be completed
All banks must be closed
MRS with BA=01 is issued (SRR)
Wait tSRR
Read issued to any bank/page
CAS latency cycles later the device returns the registers data as it would a normal read
The next command to the device can be issued tSRC after the Read command was issued.
The burst length for the SRR read is always fixed to length 2.
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Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6.7.1 SRR Register (A[n:0] = 0)
X
16 15
Reserved(0)
DQ15 DQ14 DQ13
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
13 12 11 10
Density DT DW
Density
8
Refresh
Rate
7
4
3
0
Rising Edge of DQ Bus
Revision Manufacturer
Identification Identification
SRR Register 0
DQ3
DQ2
DQ1
DQ0
Manufacturer
1
0
0
0
Winbond
128
256
512
1024
2048
Reserved
Reserved
64
DQ12 Device Type
0
1
LPDDR
Reserved
DQ10
DQ11
0
1
Device
Width
16 bits
32 bits
1
1
1
1
0
0
0
DQ9
DQ8
1
1
0
0
1
1
0
1
0
1
0
1
0
x
Refresh Rate
Reserved
0.25
Reserved
1
Reserved
Reserved
Reserved
DQ7:4 Revision ID
(See Note 1)
Note 1 : The manufacture’s revision number
starts at ‘0000’ and increments by ‘0001’ each
time a change in the manufacturer’s
specification(AC timings, or feature set), IBIS
(pull up or pull down characteristics), or
process occurs.
Note 2 : The refresh rate mulitiplier is based on the menory’s temperature sensor.
Note 3 : Required average periodic refresh interval = tREFI * multiplier
- 17 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6.7.2 Status Register Read Timing Diagram
CK
CK
Command
tSRR
tRP
CMD
NOP
MRS
BA1,BA0
01
An – A0
0
NOP
tSRC
READ
NOP
NOP
NOP
CMD
CL=3
DQS
DQ
DQ:Reg out
=Don’t Care
PCHA, or PCH
Notes :
1.SRR can only be issued after power-up sequence is complete.
2.SRR can only be issued with all banks precharged.
3.SRR CL is unchanged from value in the mode register.
4.SRR BL is fixed at 2.
5.tSRR = 2 (min).
6.tSRC = CL + 1; (min time between read to next valid command)
7.No commands other than NOP and DES are allowed between the SRR and the READ.
- 18 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6.8 Partial Array Self Refresh
With partial array self refresh (PASR), the self refresh may be restricted to a variable portion of the total array. The
whole array (default), 1/2 array, or 1/4 array could be selected. Data outside the defined area will be lost. Address
bits A0 to A2 are used to set PASR.
6.9 Automatic Temperature Compensated Self Refresh
The device has an Automatic Temperature Compensated Self Refresh feature. It automatically adjusts the refresh
rate based on the device temperature without any register update needed. To maintain backward compatibility, this
device which have Automatic TCSR, ignore (don‟t care) the inputs to address bits A3 and A4 during EMRS
programming.
6.10 Output Drive Strength
The drive strength could be set to full, half or three-quarter strength via address bits A5 and A6. The half drive
strength option is intended for lighter loads or point-to-point environments.
6.11 Commands
All commands (address and control signals) are registered on the positive edge of clock (crossing of CK going high
and CK going low).
6.11.1 Basic Timing Parameters for Commands
tCK
CK
CK
Input
tCH
tIS
Valid
tCL
tIH
Valid
Valid
NOTE: Input=A0 – An, BA0, BA1, CKE, CS, RAS, CAS, WE;
- 19 -
: Don't Care
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6.11.2 Truth Table - Commands
NAME (FUNCTION)
CS
RAS CAS
BA
A10/AP ADDR NOTES
X
X
X
2
2
DESELECT (NOP)
H
X
X
WE
X
NO OPERATION (NOP)
L
H
H
H
X
X
X
ACTIVE (Select Bank and activate row)
L
L
H
H
Valid
Row
Row
READ (Select bank and column and start read burst)
L
H
L
H
Valid
L
Col
READ with AP (Read Burst with Auto Precharge)
L
H
L
H
Valid
H
Col
WRITE (Select bank and column and start write burst)
L
H
L
L
Valid
L
Col
WRITE with AP (Write Burst with Auto Precharge)
L
H
L
L
Valid
H
Col
3
BURST TERMINATE or enter DEEP POWER DOWN
L
H
H
L
X
X
X
4, 5
PRECHARGE (Deactivate Row in selected bank)
L
L
H
L
Valid
L
X
6
PRECHARGE ALL (Deactivate rows in all banks)
L
L
H
L
X
H
X
6
AUTO REFRESH or enter SELF REFRESH
L
L
L
H
X
X
X
7, 8, 9
MODE REGISTER SET
L
L
L
L
Valid
Op-code
3
10
Notes:
1.
All states and sequences not shown are illegal or reserved.
2.
DESELECT and NOP are functionally interchangeable.
3.
Auto precharge is non-persistent. A10 High enables Auto precharge, while A10 Low disables Auto precharge.
4.
Burst Terminate applies to only Read bursts with Autoprecharge disabled. This command is undefined and should not be
used for Read with Auto precharge enabled, and for Write bursts.
5.
This command is BURST TERMINATE if CKE is High and DEEP POWER DOWN entry if CKE is Low.
6.
If A10 is low, bank address determines which bank is to be precharged. If A10 is high, all banks are precharged and
BA0~BA1 are don‟t care.
7.
This command is AUTO REFRESH if CKE is High and SELF REFRESH if CKE is low.
8.
All address inputs and I/O are „don‟t care‟ except for CKE. Internal refresh counters control bank and row addressing.
9.
All banks must be precharged before issuing an AUTO-REFRESH or SELF REFRESH command.
10. BA0 and BA1 value select between MRS and EMRS.
11. CKE is HIGH for all commands shown except SELF REFRESH and DEEP POWER-DOWN.
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Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6.11.3 Truth Table - DM Operations
FUNCTION
DM
DQ
NOTES
Write Enable
L
Valid
1
Write Inhibit
H
X
1
Notes:
1.
Used to mask write data, provided coincident with the corresponding data.
6.11.4 Truth Table - CKE
CKEn-1
CKEn
CURRENT STATE
COMMANDn
ACTIONn
NOTES
L
L
Power Down
X
Maintain Power Down
L
L
Self Refresh
X
Maintain Self Refresh
L
L
Deep Power Down
X
Maintain Deep Power Down
L
H
Power Down
NOP or DESELECT
Exit Power Down
5, 6, 9
L
H
Self Refresh
NOP or DESELECT
Exit Self Refresh
5, 7, 10
L
H
Deep Power Down
NOP or DESELECT
Exit Deep Power Down
5, 8
H
L
All Banks Idle
NOP or DESELECT
Precharge Power Down Entry
5
H
L
Bank(s) Active
NOP or DESELECT
Active Power Down Entry
5
H
L
All Banks Idle
AUTO REFRESH
Self Refresh Entry
H
L
All Banks Idle
BURST TERMINATE
Enter Deep Power Down
H
H
See the other Truth Tables
Notes:
1.
CKEn is the logic state of CKE at clock edge n; CKEn-1 was the state of CKE at the previous clock edge.
2.
Current state is the state of LPDDR SDRAM immediately prior to clock edge n.
3.
COMMANDn is the command registered at clock edge n, and ACTIONn is the result of COMMANDn.
4.
All states and sequences not shown are illegal or reserved.
5.
DESELECT and NOP are functionally interchangeable.
6.
Power Down exit time (tXP) should elapse before a command other than NOP or DESELECT is issued.
7.
SELF REFRESH exit time (tXSR) should elapse before a command other than NOP or DESELECT is issued.
8.
The Deep Power-Down exit procedure must be followed as discussed in the Deep Power-Down section of the Functional
Description.
9.
The clock must toggle at least once during the tXP period.
10. The clock must toggle at least once during the tXSR time.
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Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
6.11.5 Truth Table - Current State BANKn - Command to BANKn
CURRENT STATE
Any
Idle
Row Active
Read (Auto precharge
Disabled)
Write (Auto precharge
Disabled)
CS
RAS CAS WE
COMMAND
ACTION
NOTES
H
X
X
X
DESELECT
NOP or Continue previous operation
L
H
H
H
No Operation
NOP or Continue previous operation
L
L
H
H
ACTIVE
Select and activate row
L
L
L
H
AUTO REFRESH
Auto refresh
10
L
L
L
L
MRS
Mode register set
10
L
H
L
H
READ
Select column & start read burst
L
H
L
L
WRITE
Select column & start write burst
L
L
H
L
PRECHARGE
Deactivate row in bank (or banks)
4
L
H
L
H
READ
Select column & start new read burst
5, 6
L
H
L
L
WRITE
Select column & start write burst
5, 6, 13
L
L
H
L
PRECHARGE
Truncate read burst, start precharge
L
H
H
L
BURST
TERMINATE
Burst terminate
11
L
H
L
H
READ
Select column & start read burst
5, 6, 12
L
H
L
L
WRITE
Select column & start new write burst
5, 6
L
L
H
L
PRECHARGE
Truncate write burst & start precharge
12
Notes:
1.
The table applies when both CKEn-1 and CKEn are HIGH, and after tXSR or tXP has been met if the previous state was
Self Refresh or Power Down.
2.
DESELECT and NOP are functionally interchangeable.
3.
All states and sequences not shown are illegal or reserved.
4.
This command may or may not be bank specific. If all banks are being precharged, they must be in a valid state for
precharging.
5.
A command other than NOP should not be issued to the same bank while a READ or WRITE burst with Auto Precharge is
enabled.
6.
The new Read or Write command could be Auto Prechrge enabled or Auto Precharge disabled.
7.
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.
8.
The following states must not be interrupted by a command issued to the same bank. DESEDECT or NOP commands or
allowable commands to the other bank should be issued on any clock edge occurring during these states. Allowable
commands to the other bank are determined by its current state and this table, and according to next table.
Precharging: Starts with the 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 with AP Enabled: Starts with the registration of the READ command with Auto Precharge enabled and ends when tRP
has been met. Once tRP has been met, the bank will be in the idle state.
Write with AP Enabled: Starts with registration of a WRITE command with Auto Precharge enabled and ends when tRP has
been met. Once tRP is met, the bank will be in the idle state.
9.
The following states must not be interrupted by any executable command; DESEDECT or NOP commands must be applied
to each positive clock edge during these states.
Refreshing: Starts with registration of an AUTO REFRESH command and ends when tRFC is met. Once tRFC is met, the
LPDDR SDRAM will be in an „all banks idle‟ state.
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Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
10.
11.
12.
13.
Accessing Mode Register: Starts with registration of a MODE REGISTER SET command and ends when tMRD has been
met. Once tMRD is met, the LPDDR SDRAM will be in an „all banks idle‟ state.
Precharging All: Starts with the registration of a PRECHARGE ALL command and ends when tRP is met. Once tRP is met,
the bank will be in the idle state.
Not bank-specific; requires that all banks are idle and no bursts are in progress.
Not bank-specific. BURST TERMINATE affects the most recent READ burst, regardless of bank.
Requires appropriate DM masking.
A WRITE command may be applied after the completion of the READ burst; otherwise, a BURST TERMINATE must be
used to end the READ prior to asserting a WRITE command.
6.11.6 Truth Table - Current State BANKn, Command to BANKn
CURRENT
STATE
Any
Idle
Row Activating,
Active, or
Precharging
Read with Auto
Precharge
disabled
Write with Auto
Precharge
disabled
Read with Auto
Precharge
Write with Auto
Precharge
COMMAND
ACTION
X
DESELECT
NOP or Continue previous Operation
H
H
NOP
NOP or Continue previous Operation
X
X
X
ANY
Any command allowed to bank m
L
L
H
H
ACTIVE
L
H
L
H
READ
Select column & start read burst
8
L
H
L
L
WRITE
Select column & start write burst
8
L
L
H
L
PRECHARGE
L
L
H
H
ACTIVE
L
H
L
H
READ
Select column & start new read burst
L
H
L
L
WRITE
Select column & start write burst
L
L
H
L
PRECHARGE
L
L
H
H
ACTIVE
L
H
L
H
READ
Select column & start read burst
L
H
L
L
WRITE
Select column & start new write burst
L
L
H
L
PRECHARGE
L
L
H
H
ACTIVE
L
H
L
H
READ
Select column & start new read burst
L
H
L
L
WRITE
Select column & start write burst
L
L
H
L
PRECHARGE
L
L
H
H
ACTIVE
L
H
L
H
READ
Select column & start read burst
5, 8
L
H
L
L
WRITE
Select column & start new write burst
5, 8
L
L
H
L
PRECHARGE
CS
RAS
CAS WE
H
X
X
L
H
X
- 23 -
NOTES
Select and activate row
Precharge
Select and activate row
8
8,10
Precharge
Select and activate row
8, 9
8
Precharge
Select and activate row
5, 8
5, 8, 10
Precharge
Select and activate row
Precharge
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
Notes:
1.
The table applies when both CKEn-1 and CKEn are HIGH, and after tXSR or tXP has been met if the previous state was
Self Refresh or Power Down.
2.
DESELECT and NOP are functionally interchangeable.
3.
All states and sequences not shown are illegal or reserved.
4.
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.
5.
Read with AP enabled and Write with AP enabled: The read with Auto Precharge enabled or Write with Auto Precharge
enabled states can be broken into two parts: the access period and the precharge period. For Read with AP, the precharge
period is defined as if the same burst was executed with Auto Precharge disabled and then followed with the earliest
possible PRECHARGE command that still accesses all the data in the burst. For Write with Auto precharge, the precharge
period begins when tWR ends, with tWR measured as if Auto Precharge was disabled. The access period starts with
registration of the command and ends where the precharge period (or tRP) begins. During the precharge period, of the
Read with Auto Precharge enabled or Write with Auto Precharge enabled states, ACTIVE, PRECHARGE, READ, and
WRITE commands to the other bank may be applied; during the access period, only ACTIVE and PRECHARGE commands
to the other banks may be applied. In either case, all other related limitations apply (e.g. contention between READ data
and WRITE data must be avoided).
6.
AUTO REFRESH, SELF REFRESH, and MODE REGISTER SET commands may only be issued when all bank are idle.
7.
A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state
only.
8.
READs or WRITEs listed in the Command column include READs and WRITEs with Auto Precharge enabled and READs
and WRITEs with Auto Precharge disabled.
9.
Requires appropriate DM masking.
10. A WRITE command may be applied after the completion of data output, otherwise a BURST TERMINATE command must
be issued to end the READ prior to asserting a WRITE command.
7. OPERATION
7.1. Deselect
The DESELECT function ( CS = high) prevents new commands from being executed by the LPDDR SDRAM. The
LPDDR SDRAM is effectively deselected. Operations already in progress are not affected.
7.2. No Operation
The NO OPERATION (NOP) command is used to perform a NOP to a LPDDR SDRAM that is selected ( CS =Low).
This prevents unwanted commands from being registered during idle or wait states. Operations already in progress
are not affected.
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7.2.1 NOP Command
CK
CK
CKE
(High)
CS
RAS
CAS
WE
A0-An
BA0,BA1
= Don't Care
7.3 Mode Register Set
The Mode Register and the Extended Mode Register are loaded via the address inputs. The MODE REGISTER SET
command can only be issued when all banks are idle and no bursts are in progress, and a subsequent executable
command cannot be issued until tMRD is met.
7.3.1 Mode Register Set Command
CK
CK
CKE
(High)
CS
RAS
CAS
WE
A0-An
Code
BA0,BA1
Code
= Don't Care
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7.3.2 Mode Register Set Command Timing
CK
CK
Command
MRS
NOP
Valid
tMRD
Address
Code
Valid
: Don't Care
NOTE:Code=Mode Register / Extended Mode Register selection
(BA0,BA1)and op-code (A0-An)
7.4. Active
Before any READ or WRITE commands can be issued to a bank in the LPDDR SDRAM, a row in that bank must be
opened. This is accomplished by the ACTIVE command: BA0 and BA1 select the bank, and the address inputs
select the row to be activated. More than one bank can be active at any time.
Once a row is open, a READ or WRITE command could be issued to that row, subject to the tRCD specification.
A subsequent ACTIVE command to another row in the same bank can only be issued after the previous row has
been closed. The minimum time interval between two successive ACTIVE commands on the same bank is defined
by tRC.
7.4.1 Active Command
CK
CK
CKE
(High)
CS
RAS
CAS
WE
A0-An
RA
BA0,BA1
BA
= Don't Care
BA=BANK Address, RA=Row
Address
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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 two successive ACTIVE commands
on different banks is defined by tRRD.
The row remains active until a PRECHARGE command (or READ or WRITE command with Auto Precharge) is
issued to the bank.
A PRECHARGE (or READ with Auto Precharge or Write with Auto Precharge) command must be issued before
opening a different row in the same bank.
7.4.2 Bank Activation Command Cycle
CK
CK
Command
ACT
NOP
A0-An
Row
Row
Col
BA0,BA1
BA x
BA y
BA y
tRRD
ACT
NOP
NOP
RD/WR
NOP
tRCD
= Don't Care
7.5. Read
The READ command is used to initiate a burst read access to an active row, with a burst length as set in the Mode
Register. BA0 and BA1 select the bank, and the address inputs select the starting column location. The value of A10
determines whether or not Auto Pre-charge is used. If Auto Pre-charge is selected, the row being accessed will be
pre-charged at the end of the read burst; if Auto Pre-charge is not selected, the row will remain open for subsequent
accesses.
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7.5.1 Read Command
CK
CK
CKE
(High)
CS
RAS
CAS
WE
A0-An
CA
Enable AP
A10
AP
Disable AP
BA0,BA1
BA
= Don't Care
BA=BANK Address CA=Coulmn Address AP=Auto
Precharge
The basic Read timing parameters for DQs are shown in following figure; they apply to all Read operations.
7.5.2 Basic Read Timing Parameters
tCK
tCK
tCH
tCL
CK
CK
tDQSCK
DQS
tACmax
tDQSCK
tRPST
tRPRE
tDQSQmax
tAC
DQ
tHZ
DO n
tLZ
DO n+1
DO n+2
DO n+3
tQH
DQS
tACmin
tDQSCK
tRPRE
tQH
tDQSCK
tDQSQmax
tHZ
tAC
DO n
DQ
tLZ
DO n+1
tQH
1)DO n=Data Out from column n
2)All DQ are vaild tAC after the CK edge.
All DQ are valid tDQSQ after the DQS edge, regardless of tAC
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tRPST
DO n+2
DO n+3
tQH
= Don,t Care
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During Read bursts, DQS is driven by the LPDDR SDRAM along with the output data. The initial Low state of the
DQS is known as the read preamble; the Low state coincident with last data-out element is known as the read postamble. The first data-out element is edge aligned with the first rising edge of DQS and the successive data-out
elements are edge aligned to successive edges of DQS. This is shown in following figure with a CAS latency of 2
and 3.
Upon completion of a read burst, assuming no other READ command has been initiated, the DQs will go to High-Z.
7.5.3 Read Burst Showing CAS Latency
CK
CK
Command
Address
READ
NOP
NOP
NOP
NOP
NOP
BA Col n
CL=2
DQS
DQ
DO n
CL=3
DQS
DQ
DO n
= Don't Care
1)DO n=Data Out from column n
2)BA,Col n =Bank A,Column n
3)Burst Length=4;3 subsequent elements of Data Out appear inthe programmed order following DO n
4)Shown with nominal tAC, tDQSCK and tDQSQ
7.5.4 Read to Read
Data from a read burst may be concatenated or truncated by a subsequent READ command. The first data from the
new burst follows either the last element of a completed burst or the last desired element of a longer burst that is
being truncated. The new READ command should be issued X cycles after the first READ command, where X
equals the number of desired data-out element pairs (pairs are required by the 2n-prefetch architecture). This is
shown in following figure.
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7.5.5 Consecutive Read Bursts
CK
CK
Command
Address
READ
NOP
BA,Coln
READ
NOP
NOP
NOP
BA,Colb
CL=2
DQS
DQ
DO n
DO b
CL=3
DQS
DQ
DO n
DO b
= Don't Care
1) DO n (or b)=Data Out from column n (or column b)
2) Burst Length=4,8 or 16 (if 4, the bursts are concatenated; if 8 or 16, the second burst interrupts the first)
3) Read bursts are to an active row in the bank
4) Shown with nominal tAC, tDQSCK and tDQSQ
7.5.6 Non-Consecutive Read Bursts
A READ command can be initiated on any clock cycle following a previous READ command. Non-consecutive
Reads are shown in following figure.
CK
CK
Command
Address
READ
NOP
NOP
BA,Col n
READ
NOP
NOP
BA,Col b
CL=2
DQS
DQ
DO n
DO b
CL=3
DQS
DQ
DO n
= Don't Care
1) DO n (or b) =Data Out from column n (or column b)
2) BA,Col n (or b) =Bank A,Column n (or column b)
3) Burst Length=4; 3 subsequent elements of Data Out appear in the programmed order following DO n (or b)
4) Shown with nominal tAC, tDQSCK and tDQSQ
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7.5.7 Random Read Bursts
Full-speed random read accesses within a page or pages can be performed as shown in following figure.
CK
CK
Command
Address
READ
READ
READ
READ
NOP
BA,Col n
BA,Col x
BA,Col b
BA,Col g
NOP
CL=2
DQS
DQ
DO n
DO n'
DO x
DO x'
DO b
DO b'
DO g
DO g'
DO n
DO n'
DO x
DO x'
DO b
DO b'
CL=3
DQS
DQ
1) DO n ,etc. = Data Out from column n, etc.
n', x', etc. = Data Out elements, according to the programmed burst order
2) BA, Col n = Bank A, Column n
3) Burst Length=2,4,8 or 16 in cases shown (if burst of 4,8 or 16, the burst is interrupted)
4) Reads are to active rows in any banks
= Don't Care
7.5.8 Read Burst Terminate
Data from any READ burst may be truncated with a BURST TERMINATE command, as shown in figure. The BURST
TERMINATE latency is equal to the read (CAS) latency, i.e., the BURST TERMINATE command should be issued X
cycles after the READ command where X equals the desired data-out element pairs.
CK
CK
Command
Address
READ
BST
NOP
NOP
NOP
NOP
BA,Col n
CL=2
DQS
DQ
CL=3
DQS
DQ
1) DO n = Data Out from column n
2) BA,Col n = Bank A, Column n
3) Cases shown are bursts of 4,8 or 16 terminated after 2 data elements.
4) Shown with nominal tAC, tDQSCK and tDQSQ
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256Mb Mobile LPDDR
7.5.9 Read to Write
Data from READ burst must be completed or truncated before a subsequent WRITE command can be issued. If
truncation is necessary, the BURST TERMINATE command must be used, as shown in following figure for the case
of nominal tDQSS
CK
CK
Command
Address
READ
BST
NOP
WRITE
BA,Col n
NOP
NOP
WRITE
NOP
BA,Col b
tDQSS
CL=2
DQS
DQ
DO n
DM
Command
Address
READ
BST
NOP
NOP
BA,Col n
BA,Col b
CL=3
DQS
DQ
DO n
DM
= Don't Care
1) DO n = Data Out from column n; DI b= Data In to column b
2) Burst length = 4, 8 or 16 in the cases shown; If the burst length is 2, the BST command can be omitted
3) Shown with nominal tAC, tDQSCK and tDQSQ
7.5.10 Read to Pre-charge
A Read burst may be followed by or truncated with a PRECHARGE command to the same bank (provided Auto Precharge was not activated). The PRECHARGE command should be issued X cycles after the READ command, where
X equal the number of desired data-out element pairs. This is shown in following figure. Following the PRECHARGE
command, a subsequent command to the same bank cannot be issued until t RP is met. Note that part of the row precharge time is hidden during the access of the last data-out elements.
In the case of a Read being executed to completion, a PRECHARGE command issued at the optimum time (as
described above) provides the same operation that would result from Read burst with Auto Pre-charge enabled. 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 bursts.
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CK
CK
Command
Address
READ
NOP
PRE
NOP
NOP
Bank
(a or all)
BA,Col n
NOP
BA,Row
tRP
CL=2
DQS
DQ
DO n
CL=3
DQS
DQ
DO n
= Don't Care
1) DO n=Data Out from column n
2) Cases shown are either uninterrupted of 4, or interrupted bursts of 8 or 16
3) Shown with nominal tAC,tDQSCK and tDQSQ
4) Precharge may be applied at (BL/2) tCK after the READ command.
5) Note that Precharge may not be issued before tRAS ns after the ACTIVE command for applicable banks.
6) The ACTIVE command may be applied if tRC has been met.
7.5.11 Burst Terminate of Read
The BURST TERMINATE command is used to truncate read bursts (with Auto Pre-charge disabled). The most
recently registered READ command prior to the BURST TERMINATE command will be truncated. Note that the
BURST TERMINATE command is not bank specific.
This command should not be used to terminate write bursts.
CK
CK
CKE
(High)
CS
RAS
CAS
WE
A0-An
BA0,BA1
= Don't Care
7.6 Write
The WRITE command is used to initiate a burst write access to an active row, with a burst length as set in the Mode
Register. BA0 and BA1 select the bank, and the address inputs select the starting column location. The value of A10
determines whether or not Auto Pre-charge is used. If Auto Pre-charge is selected, the row being accessed will be
pre-charged at the end of the write burst; if Auto Pre-charge is not selected, the row will remain open for subsequent
accesses.
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7.6.1 Write Command
CK
CK
CKE
(High)
CS
RAS
CAS
WE
A0-An
CA
Enable AP
A10
AP
Disable AP
BA0,BA1
BA
= Don't Care
BA=BANK Address
CA=Coulmn Address
AP=Auto Precharge
7.6.2 Basic Write Timing Parameters
Basic Write timing parameters for DQs are shown in figure below; they apply to all Write operations.
Input data appearing on the data bus, is written to the memory array subject to the DM input logic level appearing
coincident with the data. If a given DM signal is registered Low, the corresponding data will be written to the memory;
if the DM signal is registered High, the corresponding data inputs will be ignored, and a write will not be executed to
that byte / column location.
tCK
tCH
CK
CK
Case 1:
tDQSS =
min
tDQSS
tDSH
tDQSH
tDSH
tWPST
DQS
tWPRES
tWPRE
tDS
tDH
tDQSL
DI
n
DQ, DM
Case 2:
tDQSS =
max
tCL
tDQSS
tDQSH
DQS
tWPRES
DQ, DM
tDS
tWPRE
tDH
tDSS
tDSS
tWPST
tDQSL
DI
n
= Don't Care
1) DI n=Data In for column n
2) 3 subsequent elements of Data In are applied in the programmed order following DI n.
3) tDQSS: each rising edge of DQS must fall within the +/-25% window of the corresponding positive
clock edge.
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7.6.3 Write Burst (min. and max. tDQSS)
During Write bursts, the first valid data-in element will be registered on the first rising edge of DQS following the
WRITE command, and the subsequent data elements will be registered on successive edges of DQS. The Low state
of DQS between the WRITE command and the first rising edge is called the write preamble, and the Low state on
DQS following the last data-in element is called the write post-amble.
The time between the WRITE command and the first corresponding rising edge of DQS (t DQSS) is specified with a
relatively wide range - from 75% to 125% of a clock cycle. Following figure shows the two extremes of tDQSS for a
burst of 4, upon completion of a burst, assuming no other commands have been initiated, the DQs will remain high-Z
and any additional input data will be ignored.
CK
CK
Command
Address
WRITE
NOP
NOP
NOP
NOP
NOP
BA,Col b
tDQSSmin
DQS
DQ
DM
tDQSSmax
DQS
DQ
DM
1) DI b = Data In to column b.
2) 3 subsequent elements of Data In are applied i nthe programmed order following DI b.
3) A non-interrupted burst of 4 is shown.
4) A10 is LOW with the WRITE command (Auto Precharge is disabled)
= Don't Care
7.6.4 Write to Write
Data for any WRITE burst may be concatenated with or truncated with a subsequent WRITE command. In either
case, a continuous flow of input data, can be maintained. The new WRITE command can be issued on any positive
edge of the clock following the previous WRITE command.
The first data-in element from the new burst is applied after either the last element of a completed burst or the last
desired data element of a longer burst which is being truncated. The new WRITE command should be issued X
cycles after the first WRITE command, where X equals the number of desired data-in element pairs.
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7.6.5 Concatenated Write Bursts
An example of concatenated write bursts is shown in figure below.
CK
CK
Command
Address
WRITE
NOP
WRITE
BA,Col b
NOP
NOP
NOP
BA,Col n
tDQSSmin
DQS
DQ
DI b
DI n
DM
tDQSSmax
DQS
DQ
DI b
DI n
DM
1) DI b (n)= Data in to column b (column n)
2)3 subsequent elements of Data In are applied in the programmed order following DI b.
3 subsequent elements of Data In are applied in the programmed order following DI n.
3) Non-interrupted bursts of 4 are shown.
4) Each WRITE command may be to any active bank
= Don't Care
7.6.6 Non-Consecutive Write Bursts
An example of non-consecutive write bursts is shown in figure below.
CK
CK
Command
Address
WRITE
NOP
BA,Col b
NOP
WRITE
BA,Col n
BA,Col n
NOP
NOP
tDQSSmax
DQS
DQ
DM
= Don't Care
1) Dl b (n)= Data in to column b (or column n)
2) 3 subsequent elements of Data In are applied in the programmed order following DI b.
3 subsequent elements of Data In are applied in the programmed order following DI n.
3) Non-interrupted bursts of 4 are shown.
4) Each WRITE command may be to any active bank and may be to the same or different devices.
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7.6.7 Random Write Cycles
Full-speed random write accesses within a page or pages can be performed as shown in figure below.
CK
CK
Command
Address
WRITE
WRITE
WRITE
WRITE
WRITE
BA,Col b
BA,Col x
BA,Col n
BA,Col a
BA,Col g
NOP
tDQSSmax
DQS
DQ
Di b
Di b’
Di x
Di x’
Di n
Di n’
Di a
Di a’
DM
= Don't Care
1) Dl b etc.= Data in to column b, etc.;
b’, etc.= the next Data In following Dl b, etc. according to the programmed burst order
2) Programmed burst length = 2, 4, 8 or 16 in cases shown. If burst of 4,8 or 16, burst would be truncated
3) Each WRITE command may be to any active bank and may be to the same or different devices.
7.6.8 Write to Read
Data for any Write burst may be followed by a subsequent READ command.
7.6.9 Non-Interrupting Write to Read
To follow a Write without truncating the write burst, tWTR should be met as shown in the figure below.
CK
CK
Command
WRITE
Address
BA,Col b
NOP
NOP
NOP
READ
NOP
NOP
BA,Col n
tWTR
tDQSSmax
CL=3
DQS
DQ
DI b
DM
1) Dl b = Data in to column b
= Don't Care
3 subsequent elements of Data In are applied in the programmed order following DI b.
2) A non-interrupted burst of 4 is shown.
3) tWTR is referenced from the positive clock edge after the last Data In pair.
4) A10 is LOW with the WRITE command (Auto Precharge is disabled)
5) The READ and WRITE commands are to the same device but not necessarily to the same bank.
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7.6.10 Interrupting Write to Read
Data for any Write burst may be truncated by a subsequent READ command as shown in the figure below. Note that
the only data-in pairs that are registered prior to the tWTR period are written to the internal array, and any subsequent
data-in must be masked with DM.
CK
CK
Command
Address
WRITE
NOP
BA,Col b
tDQSSmax
NOP
READ
BA,Col n
BA,Col n
NOP
tWTR
NOP
NOP
CL=3
DQS
DQ
DI b
DO n
DM
1) Dl b = Data in to column b. DO n=Data out from column n.
2) An interrupted burst of 4 is shown, 2 data elements are written.
3 subsequent elements of Data In are applied in the programmed order following DI b.
3) tWTR is referenced from the positive clock edge after the last Data In pair.
4)A10 is LOW with the WRITE command (Auto Precharge is disabled)
5) The READ and WRITE commands are to the same device but not necessarily to the same bank.
= Don't Care
7.6.11 Write to Precharge
Data for any WRITE burst may be followed by a subsequent PRECHARGE command to the same bank (provided
Auto Precharge was not activated). To follow a WRITE without truncating the WRITE burst, t WR should be met as
shown in the figure below.
7.6.12 Non-Interrupting Write to Precharge
CK
CK
Command
Address
WRITE
NOP
NOP
BA,Col b
NOP
NOP
BA,Col n
PRE
BA a (or all)
tDQSSmax
tWR
DQS
DQ
DI b
DM
1) Dl b = Data in to column b
3 subsequent elements of Data In are applied in the programmed order following DI b.
2) A non-interrupted burst of 4 is shown.
3) tWR is referenced from the positive clock edge after the last Data In pair.
4) A10 is LOW with the WRITE command (Auto Precharge is disabled)
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Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
7.6.13 Interrupting Write to Precharge
Data for any WRITE burst may be truncated by a subsequent PRECHARGE command as shown in figure below.
Note that only data-in pairs that are registered prior to the tWR period are written to the internal array, and any
subsequent data-in should be masked with DM, as shown in figure. Following the PRECHARGE command, a
subsequent command to the same bank cannot be issued until t RP is met.
CK
CK
Command
Address
WRITE
NOP
NOP
BA,Col b
NOP
NOP
BA a(or
BA,Col n
all)
tWR
tDQSSmax
*2
DQS
DQ
PRE
DI b
DM
*1
*1
1) Dl b = Data in to column b.
2) An interrupted burst of 4, 8 or 16 is shown, 2 data elements are written.
3) tWR is referenced from the positive clock edge after the last desired Data In pair.
4) A10 is LOW with the WRITE command (Auto Precharge is disabled)
5) *1=can be Don't Care for programmed burst length of 4
6) *2=for programmed burst length of 4, DQS becomes Don't Care at this point
*1
*1
= Don't Care
7.7 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 (t RP) after the PRECHARGE command is
issued.
Input A10 determines whether one or all banks are to be precharged. In case where only one bank is to be
precharged, inputs BA0, BA1 select the bank. Otherwise BA0, BA1 are treated as “Don‟t Care”.
Once a bank has been precharged, it is in the idle state and must be activated prior to any READ or WRITE
command being issued. A PRECHARGE command will be treated as a NOP if there is no open row in that bank, or if
the previously open row is already in the process of precharging.
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256Mb Mobile LPDDR
7.7.1 Precharge Command
CK
CK
CKE
(High)
CS
RAS
CAS
WE
Address
All Banks
A10
One Bank
BA0,BA1
BA
= Don't Care
BA=BANK Address
(if A10 = L,otherwise Don't Care)
7.8 Auto Precharge
Auto Precharge is a feature which performs the same individual bank precharge function as described above, but
without requiring an explicit command. This is accomplished by using A10 (A10 = High), 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. Auto Precharge is
non persistent in that it is either enabled or disabled for each individual READ or WRITE command.
Auto Precharge ensures that a precharge is initiated at the earliest valid stage within a burst. The user must not
issue another command to the same bank until the precharing time (t RP) 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 specification.
7.9 Refresh Requirements
LPDDR SDRAM devices require a refresh of all rows in any rolling 64ms interval. Each refresh is generated in one of
two ways: by an explicit AUTO REFRESH command, or by an internally timed event in SELF REFRESH mode.
Dividing the number of device rows into the rolling 64ms interval defines the average refresh interval (t REFI), which is
a guideline to controllers for distributed refresh timing.
7.10 Auto Refresh
AUTO REFRESH command is used during normal operation of the LPDDR SDRAM. This command is non
persistent, so it must be issued each time a refresh is required.
The refresh addressing is generated by the internal refresh controller. The LPDDR SDRAM requires AUTO
REFRESH commands at an average periodic interval of tREFI.
- 40 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
7.10.1 Auto Refresh Command
CK
CK
CKE
(High)
CS
RAS
CAS
WE
A0-An
BA0,BA1
= Don't Care
7.11 Self Referesh
The SELF REFRESH command can be used to retain data in the LPDDR SDRAM, even if the rest of the system is
powered down. When in the Self Refresh mode, the LPDDR SDRAM retains data without external clocking. The
LPDDR SDRAM device has a built-in timer to accommodate Self Refresh operation. The SELF REFRESH command
is initiated like an AUTO REFRESH command except CKE is LOW. Input signals except CKE are “Don‟t Care”
during Self Refresh. The user may halt the external clock one clock after the SELF REFRESH command is
registered.
Once the command is registered, CKE must be held low to keep the device in Self Refresh mode. The clock is
internally disabled during Self Refresh operation to save power. The minimum time that the device must remain in
Self Refresh mode is tRFC.
The procedure for exiting Self Refresh requires a sequence of commands. First, the clock must be stable prior to
CKE going back High. Once Self Refresh Exit is registered, a delay of at least t XS must be satisfied before a valid
command can be issued to the device to allow for completion of any internal refresh in progress.
The use of Self Refresh mode introduces the possibility that an internally timed refresh event can be missed when
CKE is raised for exit from Self Refresh mode. Upon exit from Self Refresh an extra AUTO REFRESH command is
recommended.
In the Self Refresh mode, one additional power-saving option exist: Partial Array Self Refresh (PASR); It is described
in the Extended Mode Register section.
- 41 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
7.11.1 Self Refresh Command
CK
CK
CKE
CS
RAS
CAS
WE
A0-An
BA0,BA1
= Don't Care
7.11.2 Auto Refresh Cycles Back-to-Back
CK
CK
Command
tRP
PRE
NOP
tRFC
ARF
NOP
tRFC
NOP
DQ
NOP
NOP
ACT
Ba,A
Row n
Address
A10 (AP)
ARF
Pre All
Row n
High-z
= Don't Care
Ba A, Row n = Bank A, Row n
- 42 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
7.11.3 Self Refresh Entry and Exit
CK
CK
tRP
> t RFC
tXSR
t RFC
CKE
Command
PRE
NOP
ARF
NOP
NOP
NOP
ARF
NOP
ACT
Ba, A
Row n
Address
Row n
Pre All
A10(AP)
High-z
DQ
Enter
Self Refresh
Mode
Exit from
Self Refresh
Mode
=Don't Care
Any Command
(Auto Refresh
Recommene
)
d
7.12 Power Down
Power-down is entered when CKE is registered Low (no accesses can be in progress). If power-down occurs when
all banks are idle, this mode is referred to as precharge power-down; if power-down occurs when there is a row
active in any bank, this mode is referred to as active power-down.
Entering power-down deactivates the input and output buffers, excluding CK, CK and CKE. In power-down mode,
CKE Low must be maintained, and all other input signals are “Don‟t Care”. The minimum power-down duration is
specified by tCKE. However, power-down duration is limited by the refresh requirements of the device.
The power-down state is synchronously exited when CKE is registered High (along with a NOP or DESELECT
command). A valid command may be applied t XP after exit from power-down.
For Clock Stop during Power-Down mode, please refer to the Clock Stop subsection in this specification.
7.12.1 Power-Down Entry and Exit
CK
CK
tRP
tCKE
tXP
CKE
Command
PRE
NOP
NOP
NOP
NOP
Address
A10 (AP)
DQ
NOP
Valid
Valid
Pre All
Valid
High-z
Power Down
Entry
Exit from
Power Down
Precharge Power-Down mode shown; all banks are idle and tRP
is met when Power-down Entry command is issued
- 43 -
Any Command
= Don't Care
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
7.13 Deep Power Down
The Deep Power-Down (DPD) mode enables very low standby currents. All internal voltage generators inside the
LPDDR SDRAM are stopped and all memory data is lost in this mode. All the information in the Mode Register and
the Extended Mode Register is lost.
Deep Power-Down is entered using the BURST TERMINATE command except that CKE is registered Low. All
banks must be in idle state with no activity on the data bus prior to entering the DPD mode. While in this state, CKE
must be held in a constant Low state.
To exit the DPD mode, CKE is taken high after the clock is stable and NOP commands must be maintained for at
least 200μs. After 200μs a complete re-initialization is required following steps 4 through 11 as defined for the
initialization sequence.
7.13.1 Deep Power-Down Entry and Exit
T0
T1
NOP
DPD
Ta0
Ta1
Ta2
NOP
Valid
CK
CK
CKE
Command
Address
Valid
DQS
DQ
DM
tRP
T=200us
Enter DPD
Mode
Exit DPD
Mode
1) Clock must be stable before exiting Deep Power-Down mode. That is, the clock must be cycling
within specifications by Ta0
2) Device must be in the all banks idle state prior to entering Deep Power-Down mode
3) 200us is required before any command can be applied upon exiting Deep-Down mode
4) Upon exiting Deep Power-Down mode a PRECHARGE ALL command must be issued, followed
by two REFRESH commands and a load mode register sequence
- 44 -
= Don't Care
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
7.14 Clock Stop
Stopping a clock during idle periods is an effective method of reducing power consumption.
The LPDDR SDRAM supports clock stop under the following conditions:
 the last command (ACTIVE, READ, WRITE, PRECHARGE, AUTO REFRESH or MODE REGISTER SET) has
executed to completion, including any data-out during read bursts; the number of clock pulses per access
command depends on the device‟s AC timing parameters and the clock frequency;
 the related timing conditions (tRCD, tWR, tRP, tRFC, tMRD) has been met;
 CKE is held High
When all conditions have been met, the device is either in “idle state” or “row active state” and clock stop mode
may be entered with CK held Low and CK held High.
Clock stop mode is exited by restarting the clock. At least one NOP command has to be issued before the next
access command may be applied. Additional clock pulses might be required depending on the system
characteristics.
The following Figure shows clock stop mode entry and exit.
 Initially the device is in clock stop mode
 The clock is restarted with the rising edge of T0 and a NOP on the command inputs
 With T1 a valid access command is latched; this command is followed by NOP commands in order to allow for
clock stop as soon as this access command is completed
 Tn is the last clock pulse required by the access command latched with T1
 The clock can be stopped after Tn
7.14.1 Clock Stop Mode Entry and Exit
T0
T1
T2
Tn
CK
CK
CKE
Timing
Condition
Command
NOP
Address
CMD
NOP
NOP
NOP
Valid
(High-Z)
DQ,DQS
= Don't Care
Clock
Stopped
Exit Clock
Valid
Stop
Command
Mode
Enter Clock
Stop Mode
- 45 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
8. ELECTRICAL CHARACTERISTIC
8.1 Absolute Maximum Ratings
PARAMETER
SYMBOL
VALUES
UNITS
MIN
MAX
VDD
−0.3
2.7
V
Voltage on VDDQ relative to VSS
VDDQ
−0.3
2.7
V
Voltage on any pin relative to VSS
VIN, VOUT
−0.3
2.7
V
-25
-40
−55
85
85
150
Voltage on VDD relative to VSS
Operating Case temperature :
Tc
°C
Storage Temperature
TSTG
Short Circuit Output Current
IOUT
±50
mA
PD
1.0
W
Power Dissipation
°C
8.2 Input/Output Capacitance
[Notes 1-3]
PARAMETER
Input capacitance, CK, CK
Input capacitance delta, CK, CK
Input capacitance, all other input-only pins
SYMBOL MIN
CCK
CDCK
CI
Input capacitance delta, all other input-only pins
CDI
Input/ output capacitance, DQ,DM,DQS
CIO
Input/output capacitance delta, DQ, DM, DQS
1.5
CDIO
1.5
3.0
MAX
UNITS
NOTES
3.0
pF
0.25
pF
3.0
pF
0.5
pF
5.0
pF
4
0.50
pF
4
Notes:
1.
2.
3.
These values are guaranteed by design and are tested on a sample base only.
These capacitance values are for single monolithic devices only. Multiple die packages will have parallel capacitive loads.
Although DM is an input-only pin, the input capacitance of this pin must model the input capacitance of the DQ and DQS pins. This is
required to match signal propagation times of DQ, DQS and DM in the system.
- 46 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
8.3 Electrical Characteristics and AC/DC Operating Conditions
All values are recommended operating conditions unless otherwise noted.
8.3.1 Electrical Characteristics and AC/DC Operating Conditions
PARAMETER/CONDITION
Supply Voltage
I/O Supply Voltage
SYMBOL
MIN
MAX
UNITS
VDD
1.70
1.95
V
VDDQ
1.70
1.95
V
NOTES
ADDRESS AND COMMAND INPUTS (A0~An, BA0,BA1,CKE, CS , RAS , CAS , WE )
Input High Voltage
VIH
0.8*VDDQ
VDDQ + 0.3
V
Input Low Voltage
VIL
−0.3
0.2*VDDQ
V
CLOCK INPUTS (CK, CK )
VIN
−0.3
VDDQ + 0.3
V
DC Input Differential Voltage
VID (DC)
0.4*VDDQ
VDDQ + 0.6
V
2
AC Input Differential Voltage
VID (AC)
0.6*VDDQ
VDDQ + 0.6
V
2
VIX
0.4*VDDQ
0.6*VDDQ
V
3
DC Input Voltage
AC Differential Crossing Voltage
DATA INPUTS (DQ, DM, DQS)
DC Input High Voltage
VIHD (DC)
0.7*VDDQ
VDDQ + 0.3
V
DC Input Low Voltage
VILD (DC)
−0.3
0.3*VDDQ
V
AC Input High Voltage
VIHD (AC)
0.8*VDDQ
VDDQ + 0.3
V
AC Input Low Voltage
VILD (AC)
−0.3
0.2*VDDQ
V
DATA OUTPUTS (DQ, DQS)
DC Output High Voltage (IOH=−0.1mA)
VOH
0.9*VDDQ
-
V
DC Output Low Voltage (IOL=0.1mA)
VOL
-
0.1*VDDQ
V
Leakage Current
Input Leakage Current
IiL
-1
1
uA
Output Leakage Current
IoL
-5
5
uA
Notes:
1. All voltages referenced to VSS and VSSQ must be same potential.
2. VID (DC) and VID (AC) are the magnitude of the difference between the input level on CK and CK .
3. The value of VIX is expected to be 0.5*VDDQ and must track variations in the DC level of the same.
- 47 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
8.4 IDD Specification Parameters and Test Conditions
8.4.1 IDD Specification Parameters and Test Conditions
[Recommended Operating Conditions; Notes 1-3]
(256Mb, X16)
PARAMETER
SYMBOL
Operating one
bank activeprecharge
current
TEST CONDITION
-5
-6
- 75
UNIT
IDD0
tRC = tRCmin ; tCK = tCKmin ; CKE is HIGH; CS is HIGH
between valid commands; address inputs are
SWITCHING; data bus inputs are STABLE
40
38
35
mA
Precharge
power-down
standby current
0.3
0.3
0.3
IDD2P
all banks idle, CKE is LOW; CS is HIGH, tCK
= tCKmin ; address and control inputs are
SWITCHING; data bus inputs are STABLE
0.4
0.4
0.4
Precharge
power-down
standby current
with clock stop
0.3
0.3
0.3
IDD2PS
0.4
0.4
0.4
Precharge non
power-down
standby current
IDD2N
10
10
10
mA
Precharge non
power-down
standby current
with clock stop
IDD2NS
3
3
3
mA
Active powerdown standby
current
IDD3P
3
3
3
mA
Active powerdown standby
current with
clock stop
IDD3PS
3
3
3
mA
Active non
power-down
standby current
IDD3N
25
20
20
mA
Active non
power-down
standby current
with clock stop
IDD3NS
15
12
12
mA
Operating burst
read current
IDD4R
75
70
70
mA
Operating burst
write current
IDD4W
55
50
50
mA
Auto-Refresh
Current
IDD5
50
50
50
mA
Deep PowerDown current
IDD8(4)
10
10
10
uA
all banks idle, CKE is LOW; CS is HIGH, CK =
LOW, CK = HIGH; address and control inputs
are SWITCHING; data bus inputs are STABLE
Low
power
Normal
power
Low
power
Normal
power
all banks idle, CKE is HIGH; CS is HIGH, tCK = tCKmin;
address and control inputs are SWITCHING; data bus
inputs are STABLE
mA
mA
all banks idle, CKE is HIGH; CS is HIGH, CK = LOW,
CK
= HIGH; address and control
SWITCHING; data bus inputs are STABLE
inputs
are
one bank active, CKE is LOW; CS is HIGH, tCK =
tCKmin;address and control inputs are SWITCHING; data
bus inputs are STABLE
one bank active, CKE is LOW; CS is HIGH, CK = LOW,
CK
= HIGH; address and control
SWITCHING; data bus inputs are STABLE
inputs
are
one bank active, CKE is HIGH; CS is HIGH, tCK =
tCKmin; address and control inputs are SWITCHING; data
bus inputs are STABLE
one bank active, CKE is HIGH; CS is HIGH, CK = LOW,
CK
= HIGH; address and control inputs are
SWITCHING; data bus inputs are STABLE
one bank active; BL = 4; CL = 3; tCK = tCKmin ;
continuous read bursts; IOUT = 0 mA; address inputs are
SWITCHING; 50% data change each burst transfer
one bank active; BL = 4; tCK = tCKmin ; continuous write
bursts; address inputs are SWITCHING; 50% data change
each burst transfer
tRC = tRFCmin ; tCK = tCKmin ; burst refresh; CKE is
HIGH; address and control inputs are SWITCHING; data
bus inputs are STABLE
Address and control inputs are STABLE; data bus inputs
are STABLE
- 48 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
(256Mb, X32)
PARAMETER
Operating one
bank activeprecharge
current
Precharge
power-down
standby current
SYMBOL
TEST CONDITION
-5
-6
- 75
UNIT
IDD0
tRC = tRCmin ; tCK = tCKmin ; CKE is HIGH; CS is
HIGH between valid commands; address inputs are
SWITCHING; data bus inputs are STABLE
40
38
35
mA
0.3
0.3
0.3
IDD2P
all banks idle, CKE is LOW; CS is HIGH, tCK
= tCKmin ; address and control inputs are
SWITCHING; data bus inputs are STABLE
0.4
0.4
0.4
0.3
0.3
0.3
Normal
power
0.4
0.4
0.4
all banks idle, CKE is HIGH; CS is HIGH, tCK = tCKmin;
address and control inputs are SWITCHING; data bus
inputs are STABLE
10
10
10
mA
3
3
3
mA
3
3
3
mA
3
3
3
mA
25
20
20
mA
15
12
12
mA
75
70
70
mA
55
50
50
mA
50
50
50
mA
10
10
10
uA
all banks idle, CKE is LOW; CS is HIGH, CK
Precharge
power-down
standby current
with clock stop
IDD2PS
Precharge non
power-down
standby current
IDD2N
Precharge non
power-down
standby current
with clock stop
IDD2NS
Active powerdown standby
current
IDD3P
Active powerdown standby
current with clock
stop
IDD3PS
Active non
power-down
standby current
IDD3N
Active non
power-down
standby current
with clock stop
IDD3NS
Operating burst
read current
IDD4R
Operating burst
write current
IDD4W
Auto-Refresh
Current
IDD5
Deep PowerDown current
IDD8(4)
= LOW, CK = HIGH; address and control
inputs are SWITCHING; data bus inputs are
STABLE
Low
power
Normal
power
Low
power
mA
mA
all banks idle, CKE is HIGH; CS is HIGH, CK = LOW,
CK
= HIGH; address and control
SWITCHING; data bus inputs are STABLE
inputs
are
one bank active, CKE is LOW; CS is HIGH, tCK =
tCKmin; address and control inputs are SWITCHING; data
bus inputs are STABLE
one bank active, CKE is LOW; CS is HIGH, CK = LOW,
CK
= HIGH; address and control
SWITCHING; data bus inputs are STABLE
inputs
are
one bank active, CKE is HIGH; CS is HIGH, tCK =
tCKmin; address and control inputs are SWITCHING; data
bus inputs are STABLE
one bank active, CKE is HIGH; CS is HIGH, CK = LOW,
CK
= HIGH; address and control inputs are
SWITCHING; data bus inputs are STABLE
one bank active; BL = 4; CL = 3; tCK = tCKmin ;
continuous read bursts; IOUT = 0 mA; address inputs are
SWITCHING; 50% data change each burst transfer
one bank active; BL = 4; t CK = tCKmin ; continuous write
bursts; address inputs are SWITCHING; 50% data change
each burst transfer
tRC = tRFCmin ; tCK = tCKmin ; burst refresh; CKE is
HIGH; address and control inputs are SWITCHING; data
bus inputs are STABLE
Address and control inputs are STABLE; data bus inputs
are STABLE
Notes:
1. IDD specifications are tested after the device is properly initialized.
2. Input slew rate is 1V/ns.
3. Definitions for IDD:
LOW is defined as VIN ≤ 0.1 * VDDQ;HIGH is defined as VIN ≥ 0.9 * VDDQ;STABLE is defined as inputs stable at a HIGH or LOW level;
SWITCHING is defined as:
- Address and command: inputs changing between HIGH and LOW once per two clock cycles;
- Data bus inputs: DQ changing between HIGH and LOW once per clock cycle; DM and DQS are STABLE.
4. IDD8 is a typical value at 25℃.
- 49 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
IDD6 Conditions :
IDD6
Low Power
Normal Power
TCSR Range
45℃
85℃
45℃
85℃
Full Array
200
300
250
400
1/2 Array
170
250
200
300
1/4 Array
150
220
180
250
Units
uA
Notes:
1. Measured with outputs open.
2. Internal TCSR can be supported.
- 50 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
8.5 AC Timings
[Recommended Operating Conditions: Notes 1-9]
-5
PARAMETER
DQ output access time
CL=3
from CK/ CK
CL=2
- 75
UNIT
MIN
MAX
MIN
MAX
MIN
MAX
2.0
5.0
2.0
5.0
2.0
6.0
2.0
6.5
2.0
6.5
2.0
6.5
2.0
5.0
2.0
5.0
2.0
6.0
2.0
6.5
2.0
6.5
2.0
6.5
tAC
CL=3
DQS output access time from CK/
CK
-6
SYMBOL
ns
ns
tDQSCK
CL=2
Clock high-level width
tCH
0.45
0.55
0.45
0.55
0.45
0.55
tCK
Clock low-level width
tCL
0.45
0.55
0.45
0.55
0.45
0.55
tCK
Clock half period
tHP
CL=3
Min
Min
(tCL, tCH)
Min
(tCL, tCH)
(tCL, tCH)
ns
10,11
5
6
7.5
ns
12
12
12
12
ns
12
0.48
0.6
0.8
ns
13,14,15
0.58
0.7
0.9
ns
13,14,16
0.48
0.6
0.8
ns
13,14,15
0.58
0.7
0.9
ns
13,14,16
1.6
1.6
1.8
ns
17
0.9
1.1
1.3
ns
15,18
1.1
1.3
1.5
ns
16,18
0.9
1.1
1.3
ns
15,18
1.1
1.3
1.5
ns
16,18
tCK
Clock cycle time
CL=2
DQ and DM input setup
time
NOTES
fast
tDS
slow
fast
tDH
DQ and DM input hold time
slow
tDIPW
DQ and DM input pulse width
Address and control input
setup time
fast
Address and control input
hold time
fast
tIS
slow
tIH
slow
Address and control input pulse width
tIPW
2.3
2.6
2.6
ns
17
DQ & DQS low-impedance time from
CK/ CK
tLZ
1.0
1.0
1.0
ns
19
ns
19
ns
20
ns
11
0.75
ns
11
DQ & DQS high-impedance
time from CK/ CK
CL=3
5.0
5.0
6.0
6.5
6.5
6.5
0.4
0.5
0.6
tHZ
CL=2
DQS-DQ skew
tDQSQ
DQ/DQS output hold time from DQS
tQH
Data hold skew factor
tQHS
Write command to 1st DQS latching
transition
tDQSS
0.75
1.25
0.75
1.25
0.75
1.25
tCK
DQS input high-level width
tDQSH
0.4
0.6
0.4
0.6
0.4
0.6
tCK
DQS input low-level width
tDQSL
0.4
0.6
0.4
0.6
0.4
0.6
tCK
DQS falling edge to CK setup time
tDSS
0.2
0.2
0.2
tCK
DQS falling edge hold time from CK
tDSH
0.2
0.2
0.2
tCK
MODE REGISTER SET command
period
tMRD
2
2
2
tCK
tHP-tQHS
tHP-tQHS
0.5
tHP-tQHS
0.65
- 51 -
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
-5
PARAMETER
-6
- 75
SYMBOL
MIN
Write preamble setup time
tWPRES
Write postamble
tWPST
0.4
Write preamble
tWPRE
0.25
CL = 3
MAX
MIN
0
MAX
MIN
0
0.6
0.4
0
0.6
0.4
0.25
UNIT
NOTES
ns
21
tCK
22
MAX
0.6
0.25
tCK
0.9
1.1
0.9
1.1
0.9
1.1
tCK
23
0.5
1.1
0.5
1.1
0.5
1.1
tCK
23
tRPRE
Read preamble
CL = 2
Read postamble
tRPST
0.4
0.6
0.4
0.6
0.4
0.6
tCK
ACTIVE to PRECHARGE command
period
tRAS
40
70,000
42
70,000
45
70,000
ns
ACTIVE to ACTIVE command period
tRC
AUTO REFRESH to ACTIVE/AUTO
REFRESH command period
tRAS+
tRAS+
tRAS+
tRP
tRP
tRP
tRFC
72
72
72
ns
ACTIVE to READ or WRITE delay
tRCD
15
18
22.5
ns
PRECHARGE command period
tRP
3
3
3
tCK
ACTIVE bank A to ACTIVE bank B
delay
tRRD
10
12
15
ns
WRITE recovery time
tWR
15
15
15
ns
24
Auto precharge write recovery +
precharge time
tDAL
-
-
-
tCK
25
Internal write to Read command delay
tWTR
2
2
1
tCK
Self Refresh exit to next valid command
delay
tXSR
120
120
120
ns
26
Exit power down to next valid command
delay
tXP
2
1
1
tCK
27
CKE min. pulse width (high and low
pulse width)
tCKE
1
1
1
tCK
Refresh Period
tREF
64
64
64
ms
Average periodic refresh interval (x16)
tREFI
7.8
7.8
7.8
μs
28,29
Average periodic refresh interval (x32)
tREFI
15.6
15.6
15.6
μs
28,29
MRS for SRR to READ
tSRR
2
2
2
tCK
READ of SRR to next valid command
tSRC
CL+1
CL+1
CL+1
tCK
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ns
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
Notes:
1. All voltages referenced to VSS.
2. All parameters assume proper device initialization.
3. Tests for AC timing may be conducted at nominal supply voltage levels, but the related specifications and
device operation are guaranteed for the full voltage and temperature range specified.
4. The circuit shown below represents the timing reference load used in defining the relevant timing parameters
of the part. It is not intended to be either a precise representation of the typical system environment nor a
depiction of the actual load presented by a production tester. System designers will use IBIS or other
simulation tools to correlate the timing reference load to system environment. Manufacturers will correlate to
their production test conditions (generally a coaxial transmission line terminated at the tester electronics). For
the half strength driver with a nominal 10pF load parameters tAC and tQH are expected to be in the same
range. However, these parameters are not subject to production test but are estimated by design /
characterization. Use of IBIS or other simulation tools for system design validation is suggested.
I/O
Time Reference Load
Z0 = 50 Ohms
20pF
5.
The CK/ CK input reference voltage level (for timing referenced to CK/ CK ) is the point at which CK and CK
6.
7.
cross; the input reference voltage level for signals other than CK/ CK is VDDQ/2.
The timing reference voltage level is VDDQ/2.
AC and DC input and output voltage levels are defined in the section for Electrical Characteristics and AC/DC
operating conditions.
8.
A CK/ CK differential slew rate of 2.0 V/ns is assumed for all parameters.
9.
CAS latency definition: with CL = 3 the first data element is valid at (2 * tCK + tAC) after the clock at which
the READ command was registered; with CL = 2 the first data element is valid at (tCK + tAC) after the clock at
which the READ command was registered
Min (tCL, tCH) refers to the smaller of the actual clock low time and the actual clock high time as provided to
the device (i.e. this value can be greater than the minimum specification limits of tCL and tCH)
tQH = tHP - tQHS, where tHP = minimum half clock period for any given cycle and is defined by clock high or
clock low (tCL, tCH). tQHS accounts for 1) the pulse duration distortion of on-chip clock circuits; and 2) the
worst case push-out of DQS on one transition followed by the worst case pull-in of DQ on the next transition,
both of which are, separately, due to data pin skew and output pattern effects, and p-channel to n-channel
variation of the output drivers.
The only time that the clock frequency is allowed to change is during clock stop, power-down or self-refresh
modes.
The transition time for DQ, DM and DQS inputs is measured between VIL(DC) to VIH(AC) for rising input
signals, and VIH(DC) to VIL(AC) for falling input signals.
DQS, DM and DQ input slew rate is specified to prevent double clocking of data and preserve setup and hold
times. Signal transitions through the DC region must be monotonic.
Input slew rate ≥ 1.0 V/ns.
Input slew rate ≥ 0.5 V/ns and < 1.0 V/ns.
These parameters guarantee device timing but they are not necessarily tested on each device.
The transition time for address and command inputs is measured between VIH and VIL.
10.
11.
12.
13.
14.
15.
16.
17.
18.
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Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
19. tHZ and tLZ transitions occur in the same access time windows as valid data transitions. These parameters
are not referred to a specific voltage level, but specify when the device is no longer driving (HZ), or begins
driving (LZ).
20. tDQSQ consists of data pin skew and output pattern effects, and p-channel to n-channel variation of the output
drivers for any given cycle.
21. The specific requirement is that DQS be valid (HIGH, LOW, or some point on a valid transition) on or before
the corresponding CK edge. A valid transition is defined as monotonic and meeting the input slew rate
specifications of the device. When no writes were previously in progress on the bus, DQS will be transitioning
from Hi-Z to logic LOW. If a previous write was in progress, DQS could be HIGH, LOW, or transitioning from
HIGH to LOW at this time, depending on tDQSS.
22. The maximum limit for this parameter is not a device limit. The device operates with a greater value for this
parameter, but system performance (bus turnaround) will degrade accordingly.
23. A low level on DQS may be maintained during High-Z states (DQS drivers disabled) by adding a weak pulldown element in the system. It is recommended to turn off the weak pull-down element during read and write
bursts (DQS drivers enabled).
24. At least one clock cycle is required during tWR time when in auto precharge mode.
25. Minimum 3 clocks of tDAL (=tWR + tRP) is required because it need minimum 2 clocks for tWR and minimum
1 clock for tRP.
tDAL = (tWR/tCK) + (tRP/tCK): for each of the terms above, if not already an integer, round to the next higher
integer.
26. There must be at least two clock pulses during the tXSR period.
27. There must be at least one clock pulse during the tXP period.
28. tREFI values are dependence on density and bus width.
29. A maximum of 8 Refresh commands can be posted to any given M, meaning that the maximum absolute
interval between any Refresh command and the next Refresh command is 8*tREFI.
8.5.1 CAS Latency Definition (With CL=3)
T0
T1
T2
READ
NOP
NOP
T2n
T3
T3n
T4
T4n
T5
T5n
T6
CK
CK
Command
NOP
CL=3
tDQSCKmin
tRPRE
NOP
NOP
NOP
tRPST
tDQSCKmin
DQS
All DQ,
collectively
tLZmin
T2
T2n
T3
T3n
T4
T4n
T5
T5n
tLZmin
1)DQ transitioning after DQS transition define tDQSQ window.
2)ALL DQ must transition by tDQSQ after DQS transitions, regardless of tAC
3)tAC is the DQ output window relative to CK,and is the long term component of DQ skew.
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Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
8.5.2 Output Slew Rate Characteristics
PARAMETER
MIN
MAX
UNIT
NOTES
Pull-up and Pull-Down Slew Rate for Full Strength Driver
0.7
2.5
V/ns
1,2
Pull-up and Pull-Down Slew Rate for Three-Quarter Strength Driver
0.5
1.75
V/ns
1,2
Pull-up and Pull-Down Slew Rate for Half Strength Driver
0.3
1.0
V/ns
1,2
Output Slew rate Matching ratio (Pull-up to Pull-down)
0.7
1.4
-
3
Notes:
1. Measured with a test load of 20 pF connected to VSSQ.
2. Output slew rate for rising edge is measured between VILD(DC) to VIHD(AC) and for falling edge between VIHD(DC) to VILD(AC).
3. The ratio of pull-up slew rate to pull-down slew rate is specified for the same temperature and voltage, over the entire temperature and
voltage range. For a given output, it represents the maximum difference between pull-up and pull-down drivers due to process variation.
8.5.3 AC Overshoot/Undershoot Specification
PARAMETER
Maximum peak amplitude allowed for overshoot
Maximum peak amplitude allowed for undershoot
The area between overshoot signal and VDD must be less than or equal to
The area between undershoot signal and GND must be less than or equal to
SPECIFICATION
0.5 V
0.5 V
3 V-ns
3 V-ns
8.5.4 AC Overshoot and Undershoot Definition
Overshoot Area
2.5
2.0
VDD
Voltage (V)
1.5
1.0
Max Amplitude = 0.5V
Max Area = 3V-ns
0.5
0
VSS
-0.5
Time
(ns)
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Undershoot Area
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
9. PACKAGE DIMENSIONS
9.1: LPDDR X 16
VFBGA60Ball (8X9 MM^2, Ball pitch:0.8mm)
Note:
1. Ball land:0.5mm. Ball opening:0.4mm. PCB Ball land suggested ≦0.4mm
2. Dimensions apply to Solder Balls Post-Reflow. The Pre-Reflow diameter is 0.42 on a 0.4 SMD Ball Pad.
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Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
9.2: LPDDR X 32
VFBGA90Ball (8X13 MM^2, Ball pitch:0.8mm)
Note:
1. Ball land:0.5mm. Ball opening:0.4mm. PCB Ball land suggested ≦0.4mm
2. Dimensions apply to Solder Balls Post-Reflow. The Pre-Reflow diameter is 0.42 on a 0.4 SMD Ball Pad.
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Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
10. ORDERING INFORMATION
Mobile LPDDR/LPSDR SDRAM Package Part Numbering
W 94
8
D
6
F
B
H
X
Product Line
98:mobile LPSDR SDRAM
94:mobile LPDDR SDRAM
6
E
Temperature
with standard Idd6
G:-25C~85C
Density
7:27=128M 8:28=256M
9:29=512M
with low power Idd6
E:-25C~85C
I:-40C~85C
Power Supply
D:1.8/1.8 VDD / VDDQ
Clock rate
5:5ns200MHz
6:6ns166MHz
7:7.5ns133MHz
I/O Ports width
6:16bit
2:32bit
Package Material
X: Lead-free + Halogen-free
Generation
Design revision.
Package configuration code
G: 54VFBGA, 8mmx9mm
H: 60VFBGA, 8mmx9mm
J: 90VFBGA, 8mmx13mm
Package or KGD
K: KGD
B: BGA
part number
VDD/VDDQ
I/O width Package
W948D6FBHX5I
1.8V/1.8V
16
60VFBGA 200MHz, -40C~85C, Low power
W948D6FBHX5E
1.8V/1.8V
16
60VFBGA 200MHz, -25C~85C, Low power
W948D6FBHX6E
1.8V/1.8V
16
60VFBGA 166MHz, -25C~85C, Low power
W948D6FBHX6G
1.8V/1.8V
16
60VFBGA 166MHz, -25C~85C
W948D2FBJX5I
1.8V/1.8V
32
90VFBGA 200MHz, -40C~85C, Low power
W948D2FBJX5E
1.8V/1.8V
32
90VFBGA 200MHz, -25C~85C, Low power
W948D2FBJX6E
1.8V/1.8V
32
90VFBGA 166MHz, -25C~85C, Low power
W948D2FBJX6G
1.8V/1.8V
32
90VFBGA 166MHz, -25C~85C
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Others
Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
11. REVISION HISTORY
VERSION
DATE
PAGE
A01-001
04/08/2011
All
Product datasheet for customer.
A01-002
04/18/2011
17
Update description of Status Register bit 8~10.
05/24/2011
47
48,49
51,52
55
Add IiL,IoL.
Update IDD4R & IDD4W value.
Update tHP,tDIPW,tRC,tRP,tXSR & tXP value.
8.5.2 add “Three-Quarter” parameter.
A01-003
DESCRIPTION
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Publication Release Date : May, 24, 2011
Revision A01-003
W948D6FB / W948D2FB
256Mb Mobile LPDDR
Important Notice
Winbond products are not designed, intended, authorized or warranted for use as components in systems or
equipment intended for surgical implantation, atomic energy control instruments, airplane or spaceship
instruments, transportation instruments, traffic signal instruments, combustion control instruments, or for
other applications intended to support or sustain life. Furthermore, Winbond products are not intended for
applications wherein failure of Winbond products could result or lead to a situation where in personal injury,
death or severe property or environmental damage could occur.
Winbond customers using or selling these products for use in such applications do so at their own risk and
agree to fully indemnify Winbond for any damages resulting from such improper use or sales.
----------------------------------------------------------------------------------------------------------------------------- -------------------Please note that all data and specifications are subject to change without notice.
All the trademarks of products and companies mentioned in the datasheet belong to their respective owners.
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Publication Release Date : May, 24, 2011
Revision A01-003