ALSC AS4C128M32MD2-18BCN Operating case temperature range Datasheet

AS4C128M32MD2-18BCN
AS4C128M32MD2-18BIN
Revision History
AS4C128M32MD2 - 134 ball FBGA PACKAGE
Revision
Rev 1.0
Details
Preliminary datasheet
Date
Jun 2016
Alliance Memory Inc. 511 Taylor Way, San Carlos, CA 94070 TEL: (650) 610-6800 FAX: (650) 620-9211
Alliance Memory Inc. reserves the right to change products or specification without notice
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Specifications
- Density : 4G bits
- Organization :
- 16M words x 32 bits x 8 banks
- Package :
- 134-ball FBGA
-
-
Features
- JEDEC LPDDR2-S4B compliance
- Low power consumption
- Four-bit prefetch DDR architecture
- Eight internal banks for concurrent operation
- Double data rate architecture for command, address
and data Bus
- Bidirectional and differential data strobe per byte of
data (DQS and DQS)
- DQS is edge-aligned with data for READs, centeraligned with data for WRITEs
- Differential clock inputs (CK and CK)
- Data mask (DM) for write data
- Programmable READ and WRITE latencies (RL/WL)
- Auto Refresh and Self Refresh
- Per-bank refresh for concurrent operation
- Partial-array self refresh (PASR)
- On-chip temperature sensor to control self refresh rate
for temperature compensated self refresh (TCSR)
- Deep power-down mode (DPD)
- Selectable output drive strength (DS)
- Clock stop capability
- DQ calibration offering specific DQ output patterns
- ZQ calibration
- Lead-free (RoHS compliant) and Halogen-free
Power supply :
- VDD1 = 1.8V (1.7V~1.95V)
- VDD2/VDDQ/VDDCA = 1.2V (1.14V~1.3V)
HSUL_12 interface (High Speed Unterminated Logic
1.2V)
Data rate :
- 1066Mbps RL=8
Burst lengths (BL) : 4, 8 and 16
Burst type (BT) : Sequential and interleave
Read Latency (RL) : 3, 4, 5, 6, 7, 8
Write Latency (WL) : 1, 2, 3, 4
Output driver impedance: 34.3/40/48/60/80/120 Ω
Operating case temperature range
- Commercial Tc = -25°C to +85°C
- Industrial Tc = -40°C to +85°C
Table 1. Ordering Information
Part Number
Org
Temperature
MaxClock (MHz)
Package
AS4C128M32MD2-18BCN 128Mx32
Commercial -25°C to +85°C
533
134-ball FBGA
AS4C128M32MD2-18BIN 128Mx32
Industrial
533
134-ball FBGA
Table 2. Speed Grade Information
Speed Grade
Clock Frequency
DDR2L-1066
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533MHz
-40°C to +85°C
RL
8
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tRCD (ns)
18
tRP (ns)
18
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Pin Configurations - 11.5mmX11.5mm 134B FBGA
<Top View>
A1
1
2
3
4
5
6
7
8
9
10
A
DNU
DNU
NB
NB
NB
NB
NB
NB
DNU
DNU
A
B
DNU
NC
NC
NB
VDD2
VDD1
DQ31
DQ29
DQ26
DNU
B
C
VDD1
VSS
NC
NB
VSS
VSS
VDDQ
DQ25
VSS
VDDQ
C
D
VSS
VDD2
ZQ
NB
VDDQ
DQ30
DQ27
DQS3
'46
VSS
D
E
VSS
CA9
CA8
NB
DQ28
DQ24
DM3
DQ15
VDDQ
VSS
E
F
VDDCA
CA6
CA7
NB
VSS
DQ11
DQ13
DQ14
DQ12
VDDQ
F
G
VDD2
CA5
VREFCA
NB
'46
DQS1
DQ10
DQ9
DQ8
VSS
G
H
VDDCA
VSS
&.
NB
DM1
VDDQ
NB
NB
NB
NB
H
J
VSS
NC
CK
NB
VSS
VDDQ
VDD2
VSS
VREFDQ
NB
J
K
CKE
NC
NC
NB
DM0
VDDQ
NB
NB
NB
NB
K
L
&6
NC
NC
NB
'46
DQS0
DQ5
DQ6
DQ7
VSS
L
M
CA4
CA3
CA2
NB
VSS
DQ4
DQ2
DQ1
DQ3
VDDQ
M
N
VSS
VDDCA
CA1
NB
DQ19
DQ23
DM2
DQ0
VDDQ
VSS
N
P
VSS
VDD2
CA0
NB
VDDQ
DQ17
DQ20
DQS2
'46
VSS
P
R
VDD1
VSS
NC
NB
VSS
VSS
VDDQ
DQ22
VSS
VDDQ
R
T
DNU
NC
NC
NB
VDD2
VDD1
DQ16
DQ18
DQ21
DNU
T
U
DNU
DNU
NB
NB
NB
NB
NB
NB
DNU
DNU
U
1
2
3
4
5
6
7
8
9
10
NB (No Ball)
DNU (Do Not Use)
NC
(No Connect)
4Gb LPDDR2 SDRAM Signals and Addressing
Configuration
128Mb x 32
DQ
[31:0]
DQS / DM
[3:0] / [3:0]
CA
[9:0]
Bank Address
BA0 ~ BA2
Row Address
R0 ~ R13
Column Address
C0 ~ C9
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Signal Pin Description
Pin
Type
Function
CK, CK
(CK, CK#)
(CK_t, CK_c)
Input
Clock : CK and CK are differential clock inputs. All CA inputs are sampled onboth rising and falling
edges of CK. CS and CKE inputs are sampled at the risingedge of CK. AC timings are referenced to
clock.
CKE
Input
Clock Enable : CKE HIGH activates and CKE LOW deactivates the internal clocksignals, input buffers,
and output drivers. Power-saving modes are entered andexited via CKE transitions. CKE is considered
part of the command code. CKE issampled at the rising edge of CK.
CS
(CS#)
(CS_n)
Input
Chip Select : CS is considered part of the command code and is sampled at therising edge of CK.
CA0~CA9
Input
Command/address inputs: Provide the command and address inputs accordingto the command truth
table.
DM0~DM3
Input
Input Data Mask : DM is an input mask signal for write data. Although DM ballsare input-only, the DM
loading is designed to match that of DQ and DQS balls.DM[3:0] is DM for each of the four data bytes,
respectively.
DQ0~DQ31
DQS[3:0]
(DQS_t[3:0]),
DQS[3:0]
DQS#[3:0]
(DQS_c[3:0])
Input/output Data input/output: Bidirectional data bus.
Input/output Data strobe: The data strobe is bidirectional (used for read and write data) andcomplementary (DQS
and DQS). It is edge-aligned output with read data and centered input with write data. DQS[3:0]/
DQS[3:0] is DQS for each of the four data bytes, respectively.
NC
No Connect: No internal electrical connection is present.
ZQ
Input
VDD1
Supply
Core power: Supply 1.
VDD2
Supply
Core power: Supply 2.
VDDQ
Supply
DQ power supply: Isolated on the die for improved noise immunity.
VDDCA
Supply
Command/address power supply: Command/address power supply.
VREFDQ,
VREFCA
Supply
Reference voltage: VREFCA is reference for command/address input buffers,VREFDQ is reference
for DQ input buffers.
VSS
Supply
Common ground
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External impedance (240 ohm): This signal is used to calibrate the device out-put impedance.
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Functional Block Diagram
128Mb X 32 LPDDR2
Vss
VDD1 VDD2 VDDQ VDDCA
VREFCA
VREFDQ
&6
CKE
CK
LPDDR2
&.
Die 0
ZQ
RZQ
DM[3:0]
CA[9:0]
DQ[31:0]
DQS[3:0]
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Simplified State Diagram
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Basic Functionality
LPDDR2-S4 uses the double data rate architecture on the Command/Address (CA) bus to reduce the number of input
pins in the system. The 10-bit CA bus contains command, address, and Bank/Row Buffer information. Each command
uses one clock cycle, during which command information is transferred on both the positive and negative edge of the
clock. Prior to normal operation, the DDR3 SDRAM must be powered up and initialized in a predefined manner. The following sections provide detailed information covering device reset and initialization, register definition, command
descriptions and device operation.
To achieve high-speed operation, our LPDDR2-S4 SDRAM uses the double data rate architecture and adopt 4nprefetch interface designed to transfer two data per clock cycle at the I/O pins. A single read or write access for the
LPDDR2-S4 effectively consists of a single 4n-bit wide, one clock cycle data transfer at the internal SDRAM core and
four corresponding n-bit wide, one-half-clock-cycle data transfer at the I/O pins. Read and write accesses to the
LPDDR2-S4 are burst oriented; accesses start at a selected location and continue for a programmed number of locations in a programmed sequence.
For LPDDR2-S4 devices, accesses begin with the registration of an Active command, which is then followed by a Read
or Write command. The address and BA bits registered coincident with the Active command are used to select the row
and the Bank to be accessed. The address bits registered coincident with the Read or Write command are used to
select the Bank and the starting column location for the burst access.
An auto precharge function may be enabled to provide a self-timed row precharge that is initiated at the end of the burst
access. As with standard DDR SDRAMs, the pipelined, multibank architecture of the LPDDR2-S4 SDRAMs supports
concurrent operation, thereby providing high effective bandwidth by hiding row precharge and activation time.
An auto refresh mode is provided, along with a power saving power-down mode. Deep power-down mode is offered to
achieve maximum power reduction by eliminating the power of the memory array. Data will not be retained after device
enters deep power-down mode. Two self refresh features, temperature-compensated self refresh (TCSR) and partial
array self refresh (PASR), offer additional power saving. TCSR is controlled by the automatic on-chip temperature sensor. The PASR can be customized using the extended mode register settings. The two features may be combined to
achieve even greater power saving. The DLL that is typically used on standard DDR devices is not necessary on the
LPDDR2-S4 SDRAM. It has been omitted to save power.
Prior to normal operation, the LPDDR2-S4 SDRAM must be initialized. The following sections provide detailed information covering device initialization, register definition, command descriptions and device operation.
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Power-Up, Initialization, and Power-Off
LPDDR2 devices must be powered up and initialized in a predefined manner. Power-up and initialization by means other
than those specified will result in undefined operation.
Power Ramp and Device Initialization
The following sequence must be used to power up the device. Unless specified otherwise, this procedure is mandatory
and applies to devices.
Voltage Ramp:
While applying power (after Ta), CKE must be held LOW (=<0.2 x VDDCA), and all other inputs must be between VILmin
and VIHmax. The device outputs remain at High-Z while CKE is held LOW. Following the completion of the voltage ramp
(Tb), CKE must be maintained LOW. DQ, DM, DQS and DQS voltage levels must be between VSSQ and VDDQ during
voltage ramp to avoid latch up. CK, CK, CS, and CA input levels must be between VSSCA and VDDCA during voltage
ramp to avoid latch-up.
The following conditions apply:
Ta is the point where any power supply first reaches 300 mV.
After Ta is reached, VDD1 must be greater than VDD2 - 200 mV.
After Ta is reached, VDD1 and VDD2 must be greater than VDDCA - 200 mV.
After Ta is reached, VDD1 and VDD2 must be greater than VDDQ - 200 mV.
After Ta is reached, VREF must always be less than all other supply voltages.
The voltage difference between any of VSS, VSSQ, and VSSCA pins may not exceed 100 mV.
Tb is the point when all supply voltages are within their respective min/max operating conditions. Reference voltages
shall be within their respective min/max operating conditions a minimum of 5 clocks before CKE goes high.
Power ramp duration tINIT0 (Tb - Ta) must be no greater than 20 ms.
For supply and reference voltage operating conditions, see DC power table.
Beginning at Tb, CKE must remain LOW for at least Tinit1 = 100 ns, after which CKE can be asserted HIGH. The clock
must be stable at least Tinit2 = 5 x Tck prior to the first CKE LOW-to-HIGH transition (Tc). CKE, CS, and CA inputs must
observe setup and hold requirements (Tis, Tih) with respect to the first rising clock edge (as well as to subsequent falling
and rising edges).
If any MRRs are issued, the clock period must be within the range defined for tCKb (18ns to 100ns). MRWs can be
issued at normal clock frequencies as long as all AC timings are met. Some AC parameters (for example, Tdqsck) could
have relaxed timings (such as tDQSCKb) before the system is appropriately configured. While keeping CKE HIGH, NOP
commands must be issued for at least Tinit3 = 200us (Td).
RESET Command:
After Tinit3 is satisfied, the MRW RESET command must be issued (Td). An optional PRECHARGE ALL command can
be issued prior to the MRW RESET command. Wait at least Tinit4=1us while keeping CKE asserted and issuing NOP
commands.
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MRRs and Device Auto Initialization (DAI) Polling:
After Tinit4 is satisfied (Te), only MRR commands and power-down entry/exit commands are supported. After Te, CKE
can go LOW in alignment with power-down entry and exit specifications. Use the MRR command to poll the DAI bit and
report when device auto initialization is complete; otherwise, the controller must wait a minimum of Tinit5, or until the DAI
bit is set before proceeding. As the memory output buffers are not properly configured by Te, some AC parameters must
have relaxed timings before the system is appropriately configured. After the DAI bit (MR0, DAI) is set to zero by the
memory device (DAI complete), the device is in the idle state (Tf ). DAI status can be determined by issuing the MRR
command to MR0. The device sets the DAI bit no later than Tinit5 after the RESET command. The controller must wait
at least Tinit5 or until the DAI bit is set before proceeding.
ZQ Calibration:
After Tinit5 (Tf ), the MRW initialization calibration (ZQ_CAL) command can be issued to the memory (MR10). For
LPDDR2 devices that do not support ZQ calibration, this command will be ignored. This command is used to calibrate
output impedance over process, voltage, and temperature. In systems where more than one LPDDR2 device exists on
the same bus, the controller must not overlap MRW ZQ_CAL commands. The device is ready for normal operation after
Tzqinit.
Normal Operation:
After Tzqinit (Tg), MRW commands must be used to properly configure the memory (for example the output buffer drive
strength, latencies, etc.). Specifically, MR1, MR2, and MR3 must be set to configure the memory for the target frequency
and memory configuration.After the initialization sequence is complete, the device is ready for any valid command. After
Tg, the clock frequency can be changed using the procedure described in “Input Clock Frequency Changes and Clock
Stop Events”.
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Power Ramp and Initialization Sequence
Symbol
Value
min
tINIT0
max
20
Unit
Comment
ms
Maximum Power Ramp Time
tINIT1
100
ns
Minimum CKE low time after completion of power ramp
tINIT2
5
tCK
Minimum stable clock before first CKE high
tINIT3
200
Ps
Minimum Idle time after first CKE assertion
tINIT4
1
Ps
Minimum Idle time after Reset command
S: 10
Ps
N: vendor
Ps
Maximum duration of
Device Auto-Initialization
tINIT5
tZQINIT
1
tCKE
18
100
Ta
Tb
Ps
ZQ Initial Calibration for LPDDR2-S4 and LPDDR2-N
devices
ns
Clock cycle time during boot
Tc
Td
Te
Tg
Tf
tINIT2 = 5 tCK (min)
CK_t / CK_c
tINIT0 = 20 ms (max)
Supplies
tINIT3 = 200 us (min)
tINIT1 = 100 ns (min)
CKE
PD
tISCKE
tINIT5
tZQINIT
tINIT4 = 1 us (min)
CA*
RESET
MRR
ZQC
Valid
DQ
* Midlevel on CA bus means: valid NOP
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Initialization after RESET (without voltage ramp)
If the RESET command is issued before or after the power-up initialization sequence, the re-initialization procedure
must begin at Td.
Power-Off Sequence
Use the following sequence to power off the device. Unless specified otherwise, this procedure is mandatory and
applies to devices. While powering off, CKE must be held LOW (=< 0.2 x VDDCA); all other inputs must be between
VILmin and VIHmax. The device outputs remain at High-Z while CKE is held LOW.
DQ, DM, DQS, and DQS voltage levels must be between VSSQ and VDDQ during the power-off sequence to avoid
latch-up. CK, CK, CS, and CA input levels must be between VSSCA and VDDCA during the power-off sequence to
avoid latch-up.
Tx is the point where any power supply decreases under its minimum value specified in the DC operating condition
table.
Tz is the point where all power supplies are below 300 mV. After Tz, the device is powered off.
The time between Tx and Tz (tPOFF) shall be less than 2s.
The following conditions apply:
Between Tx and Tz, VDD1 must be greater than VDD2 - 200 mV.
Between Tx and Tz, VDD1 and VDD2 must be greater than VDDCA - 200 mV.
Between Tx and Tz, VDD1 and VDD2 must be greater than VDDQ - 200 mV.
Between Tx and Tz, VREF must always be less than all other supply voltages.
The voltage difference between any of VSS, VSSQ, and VSSCA pins may not exceed 100 mV.
Symbol
tPOFF
Value
min
max
-
2
Unit
Comment
S
Maximum Power-off ramp time
Uncontrolled Power-Off Sequence
When an uncontrolled power-off occurs, the following conditions must be met:
At Tx, when the power supply drops below the minimum values specified, all power supplies must be turned off and all
power-supply current capacity must be at zero, except for any static charge remaining in the system. After Tz (the point
at which all power supplies first reach 300Mv), the device must power off. The time between Tx and Tz must not exceed
2s. During this period, the relative voltage between power supplies is uncontrolled. VDD1 and VDD2 must decrease with
a slope lower than 0.5 V/us between Tx and Tz. An uncontrolled power-off sequence can occur a maximum of 400 times
over the life of the device.
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Mode Register Definition
LPDDR2 devices contain a set of mode registers used for programming device operating parameters, reading device
information and status, and for initiating special operations such as DQ calibration, ZQ calibration, and device reset.
Mode Register Assignment and Definition
Table below shows the mode registers for LPDDR2 SDRAM. Each register is denoted as “R”, if it can be read but not
written, “W” if it can be written but not read, and “R/W” if it can be read and written. Mode Register Read Command shall
be used to read a register. Mode Register Write Command shall be used to write a register.
Mode Register Assignment
MR#
MA<0:7>
Function
Access OP7
OP6
OP5
OP4
OP3
OP2
OP1
OP0
DA
DAI
00
00H
Device Info.
R
01
01H
Device Feature1
W
02
02H
Device Feature2
W
(RFU)
RL & WL
03
03H
I/O Config-1
W
(RFU)
DS
04
04H
Refresh Rate
R
05
05H
Basic Config-1
R
LPDDR2 Manufacturer ID
06
06H
Basic Config-2
R
Revision ID1
07
07H
Basic Config-3
R
Revision ID2
08
08H
Basic Config-4
R
09
09H
Test Mode
W
Vendor-Specific Test Mode
10
0AH
IO Calibration
W
Calibration Code
11~15
0BH~0FH
(reserved)
16
10H
PASR_BANK
W
Bank Mask
17
11H
PASR_Seg
W
Segment Mask
18~19
12H~13H
(Reserved)
20~31
18H~1FH
Reserved for NVM
32
20H
DQ calibration pattern A
33~39
21H~27H
(Do Not Use)
40
28H
DQ calibration pattern B
41~47
29H~2FH
(Do Not Use)
48~62
30H~3EH
(Reserved)
63
3FH
Reset
64~126
40H~7EH
(Reserved)
127
7FH
(Do Not Use)
128~190
80H~BEH
(Reserved)
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(RFU)
nWR (for AP)
TUF
I/O width
WC
BT
BL
(RFU)
Refresh Rate
Density
Type
(RFU)
(RFU)
R
See “Data Calibration Pattern Description”
R
See “Data Calibration Pattern Description”
(RFU)
W
X
(RFU)
(RFU)
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MR#
MA<0:7>
Function
191
BFH
(Do Not Use)
192~254
C0H~FEH
(Reserved)
255
FFH
(Do Not Use)
Access OP7
OP6
OP5
OP4
OP3
OP2
OP1
OP0
(RFU)
Notes:
1. RFU bits shall be set to “0” during Mode Register writes.
2. RFU bits shall be read as “0” during Mode Register reads.
3. All Mode Registers from that are specified as RFU or write-only shall return undefined data when read and DQS shall
be toggled.
4. All Mode Registers that are specified as RFU shall not be written.
5. Writes to read-only registers shall have no impact on the functionality of the device.
MR0_Device Information (MA<7:0> = 00H)
MR#
MA<0:7>
Function
Access OP7
Device Info.
OP6
R
OP5
OP4
00
00H
OP0
DI (Device Information)
Read-only
0B: DAI complete
1B: DAI still in progress
OP1
DAI (Device Auto-Initialization Status)
Read-only
0B: S2 or S4 SDRAM
1B: Do Not Use
OP3
OP2
OP1
OP0
DA
DAI
OP1
OP0
(RFU)
MR1_Device Feature 1 (MA<7:0> = 01H)
MR#
MA<0:7>
01
01H
Function
Device Feature1
Access OP7
W
OP6
nWR (for AP)
OP5
OP4
OP3
WC
BT
OP2
BL
OP<2:0>
BL (Burst Length)
Write-only
010B: BL4 (default)
011B: BL8
100B: BL16
All others: reserved
OP3
BT*1 (Burst Type)
Write-only
0B: Sequential (default)
1B: Interleaved (allowed for SDRAM only)
OP4
WC (Wrap)
Write-only
0B: Wrap (default)
1B: No wrap (allowed for SDRAM BL4 only)
nWR*2
Write-only
001B: nWR=3 (default)
010B: nWR=4
011B: nWR=5
100B: nWR=6
101B: nWR=7
110B: nWR=8
All others: reserved
OP<7:5>
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Notes:
1. BL16, interleaved is not an official combination to be supported.
2. Programmed value in Nwr register is the number of clock cycles which determines when to start internal precharge
operation for a write burst with AP enabled. It is determined by RU(tWR/tCK).
Burst Sequence by BL, BT, and WC
C3 C2 C1 C0 WC BT BL
X
X 0B 0B
X
X 1B 0B
X
X
X 0B
wrap any
4
nw any
seq
X 1B 0B 0B
X 1B 1B 0B
X 0B 0B 0B
wrap
X 0B 1B 0B
8
int
X 1B 0B 0B
X 1B 1B 0B
X
X
X 0B
1
2
3
4
0
1
2
3
2
3
0
1
y
X 0B 0B 0B
X 0B 1B 0B
Burst Cycle Number and Burst Address Sequence
5 6 7 8 9 10 11 12 13 14 15 16
y+1 y+2 y+3
0
1
2
3
4 5 6 7
2
3
4
5
6 7 0 1
4
5
6
7
0 1 2 3
6
7
0
1
2 3 4 5
0
1
2
3
4 5 6 7
2
3
0
1
6 7 4 5
4
5
6
7
0 1 2 3
6
7
4
5
2 3 0 1
nw any
illegal (not allowed)
0B 0B 0B 0B
0
1
2
3
4 5 6 7 8 9
A
B
C
D
E
F
0B 0B 1B 0B
2
3
4
5
6 7 8 9 A B
C
D
E
F
0
1
0B 1B 0B 0B
4
5
6
7
8 9 A B C D
E
F
0
1
2
3
6
7
8
9
A B C D E F
0
1
2
3
4
5
8
9
A
B
C D E F 0 1
2
3
4
5
6
7
0B 1B 1B 0B
1B 0B 0B 0B wrap
seq
16
1B 0B 1B 0B
A
B
C
D
E F 0 1 2 3
4
5
6
7
8
9
1B 1B 0B 0B
C
D
E
F
0 1 2 3 4 5
6
7
8
9
A
B
1B 1B 1B 0B
E
F
0
1
2 3 4 5 6 7
8
9
A
B
C
D
X
X
X 0B
int
illegal (not allowed)
X
X
X 0B
nw any
illegal (not allowed)
Notes:
1. C0 input is not present on CA bus. It is implied zero.
2. For BL=4, the burst address represents C1 - C0.
3. For BL=8, the burst address represents C2 - C0.
4. For BL=16, the burst address represents C3 - C0.
5. For no-wrap, BL4, the burst must not cross the page boundary or the sub-page boundary. The variable y can start at
any address with C0 equal to 0, but must not start at any address shown bellow.
Confidential
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Non-Wrap Restrictions
64Mb
128Mb/256Mb
512Mb/1Gb/2Gb
4Gb/6Gb/8Gb
Not across full page boundary
x8
1FE, 1FF, 000, 001 3FE, 3FF, 000, 001 7FE, 7FF, 000, 001 FFE, FFF, 000, 001
x16
FE, FF, 00, 01
x32
7E, 7F, 00, 01
1FE, 1FF, 000, 001 3FE, 3FF, 000, 001 7FE, 7FF, 000, 001
FE, FF, 00, 01
1FE, 1FF, 000, 001 3FE, 3FF, 000, 001
Not across sub page boundary
07E, 07F, 080, 081 0FE, 0FF, 100, 101 1FE, 1FF, 200, 201 3FE, 3FF, 400, 401
x8
0FE, 0FF, 100, 101 1FE, 1FF, 200, 201 3FE, 3FF, 400, 401 7FE, 7FF, 800, 801
17E, 17F, 180, 181 2FE, 2FF, 300, 301 5FE, 5FF, 600, 601 BFE, BFF, C00, C01
x16
7E, 7F, 80, 81
x32
None
0FE, 0FF, 100, 101 1FE, 1FF, 200, 201 3FE, 3FF, 400, 401
None
None
None
Notes: Non-wrap BL= 4 data orders shown are prohibited.
MR2_Device Feature 2 (MA<7:0> = 02H)
MR#
MA<0:7>
02
02H
OP<3:0>
Function
Access OP7
Device Feature2
OP6
W
RL & WL (Read Latency & Write Latency)
OP5
OP4
OP3
(RFU)
Write-only
OP2
OP1
OP0
RL & WL
0001B: RL = 3 / WL = 1 (default)
0010B: RL = 4 / WL = 2
0011B: RL = 5 / WL = 2
0100B: RL = 6 / WL = 3
0101B: RL = 7 / WL = 4
0110B: RL = 8 / WL = 4
All others: reserved
MR3_I/O Configuration 1 (MA<7:0> = 03H)
MR#
MA<0:7>
03
OP<3:0>
03H
Function
I/O Config-1
DS (Drive Strength)
Confidential
Access OP7
OP6
W
OP5
OP4
OP3
(RFU)
Write-only
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OP2
OP1
OP0
DS
0000B: reserved
0001B: 34.3-ohm typical
0010B: 40-ohm typical (default)
0011B: 48-ohm typical
0100B: 60-ohm typical
0101B: reserved
0110B: 80-ohm typical
0111B: 120-ohm typical
All others: reserved
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MR4_Device Temperature (MA<7:0> = 04H)
MR#
MA<0:7>
04
Function
04H
OP<2:0>
OP7
Access OP7
R
OP6
OP5
TUF
OP4
OP3
OP2
(RFU)
OP1
OP0
Refresh Rate
Refresh Rate
Read-only
000B: SDRAM Low temperature operating limit exceeded
001B: 4x tREFI, 4x tREFIpb, 4x tREFW
010B: 2x tREFI, 2x tREFIpb, 2x tREFW
011B: 1x tREFI, 1x tREFIpb, 1x tREFW (<=85’C)
100B: Reserved
101B: 0.25x tREFI, 0.25x tREFIpb, 0.25x tREFW, do not derate SDRAM AC timing
110B: 0.25x tREFI, 0.25x tREFIpb, 0.25x tREFW, de-rate
SDRAM AC timing
111B: SDRAM High temperature operating limit exceeded
TUF (Temperature Update Flag)
Read-only
0B: OP<2:0> value has not changed since last read of MR4.
1B: OP<2:0> value has changed since last read of MR4.
Notes:
1. A Mode Register Read from MR4 will reset OP7 to “0”.
2. OP7 is reset to “0” at power-up.
3. If OP2 equals “1”, the device temperature is greater than 85’C.
4. OP7 is set to “1”, if OP2~OP0 has changed at any time since the last read of MR4.
5. LPDDR2 might not operate properly when OP<2:0> = 000B or 111B.
6. For specified operating temperature range and maximum operating temperature.
7. LPDDR2 devices must be derated by adding 1.875ns to the following core timing parameters: Trcd, Trc, Tras, Trp,
and Trrd. The Tdqsck parameter must be derated .. Prevailing clock frequency specifications and related setup and hold
timings remain unchanged.
8. The recommended frequency for reading MR4 is provided in “Temperature Sensor”.
MR5_Basic Configuration 1 (MA<7:0> = 05H)
MR#
MA<0:7>
05
05H
OP<7:0>
Function
Basic Config-1
Access OP7
OP6
OP5
R
Manufacturer ID
OP4
OP3
OP2
OP1
OP0
LPDDR2 Manufacturer ID
Read-only
See JESD-TBD LPDDR2 Manufacturer ID encodings
MR6_Basic Configuration 2 (MA<7:0> = 06H)
MR#
MA<0:7>
06
OP<7:0>
06H
Revision ID1
Confidential
Function
Basic Config-2
Access OP7
OP6
OP5
R
OP4
OP3
OP2
OP1
OP0
Revision ID1
Read-only
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Reserved
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MR7_Basic Configuration 3 (MA<7:0> = 07H)
MR#
MA<0:7>
07
07H
OP<7:0>
Function
Basic Config-3
Access OP7
OP6
OP5
R
Revision ID1
OP4
OP3
OP2
OP1
OP0
OP2
OP1
OP0
Revision ID2
Read-only
Reserved
MR8_Basic Configuration 4 (MA<7:0> = 08H)
MR#
MA<0:7>
08
08H
Function
Basic Config-4
Access OP7
R
OP6
OP5
OP4
I/O width
OP3
Density
OP<1:0>
Type
Read-only
00B: S4 SDRAM
01B: S2 SDRAM
10B: N NVM
11B: Reserved
OP<5:2>
Density
Read-only
0000B: 64Mb
0001B: 128Mb
0010B: 256Mb
0011B: 512Mb
0100B: 1Gb
0101B: 2Gb
0110B: 4Gb
1110B: 6Gb
0111B: 8Gb
1000B: 16Gb
1001B: 32Gb
All others: reserved
OP<7:6>
I/O width
Read-only
00B: x32
01B: x16
10B: x8
11B: not used
Type
MR9_Test Mode (MA<7:0> = 09H)
MR#
MA<0:7>
09
OP<7:0>
09H
Function
Test Mode
Vendor-Specific Test Mode
Confidential
Access OP7
OP6
W
OP5
OP4
OP3
OP2
OP1
OP0
Vendor-Specific Test Mode
Write-only
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MR10_Calibration (MA<7:0> = 0AH)
MR#
MA<0:7>
10
0AH
OP<7:0>
Function
IO Calibration
Access OP7
OP6
OP5
W
Calibration Code
OP4
OP3
OP2
OP1
OP0
Calibration Code
Write-only
0xFF: Calibration command after initialization
0xAB: Long calibration
0x56: Short calibration
0xC3: ZQ Reset
All others: Reserved
Notes:
1. Host processor shall not write MR10 with “Reserved” values.
2. LPDDR2 devices shall ignore calibration command, when a “Reserved” values is written into MR10.
3. See AC timing table for the calibration latency.
4. If ZQ is connected to VSSCA through RZQ, either the ZQ calibration function (see “MRW ZQ Calibration Command”)
or default calibration (through the ZQ RESET command) is supported. If ZQ is connected to VDDCA, the device operates with default calibration, and ZQ calibration commands are ignored. In both cases, the ZQ connection must not
change after power is supplied to the device.
5. Devices that do not support calibration ignore the ZQ calibration command.
6. Optionally, the MRW ZQ Initialization Calibration command will update MR0 to indicate RZQ pin connection.
MR11:15_(Reserved) (MA<7:0> = 0BH- 0FH)
MR#
MA<0:7>
Function
11~15
0BH~0FH
(reserved)
OP<7:0>
Access OP7
OP6
OP5
OP4
OP3
OP2
OP1
OP0
OP2
OP1
OP0
(RFU)
RFU
MR16_PASR_Bank Mask (MA<7:0> = 010H)
MR#
MA<0:7>
16
OP<7:0>
10H
Function
PASR_BANK
Bank Mask Code
Confidential
Access OP7
OP6
W
OP5
OP4
OP3
Bank Mask
Write-only
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0B: refresh enable to the bank (=unmasked, default)
1B: refresh blocked (=masked)
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OP
Bank Mask
4 Bank
8 Bank
0
XXXXXXX1
Bank 0
Bank 0
1
XXXXXX1X
Bank 1
Bank 1
2
XXXXX1XX
Bank 2
Bank 2
3
XXXX1XXX
Bank 3
Bank 3
4
XXX1XXXX
-
Bank 4
5
XX1XXXXX
-
Bank 5
6
X1XXXXXX
-
Bank 6
7
1XXXXXXX
-
Bank 7
Notes: This table indicates tha range of row addresses in each masked segment. X is don’t care for a particular segment.
MR17_PASR_Segment Mask (MA<7:0> = 011H)
MR#
MA<0:7>
17
OP<7:0>
11H
Function
Access OP7
PASR_Seg
Segment Mask Code
OP6
W
OP4
OP3
OP2
OP1
OP0
Segment Mask
Write-only
Segment Mask
OP5
0B: refresh enable to the segment (=unmasked, default)
1B: refresh blocked (=masked)
1Gb
2Gb, 4Gb
8Gb
R12:10
R13:11
R14:12
Segment
OP
0
0
XXXXXXX1
000B
1
1
XXXXXX1X
001B
2
2
XXXXX1XX
010B
3
3
XXXX1XXX
011B
4
4
XXX1XXXX
100B
5
5
XX1XXXXX
101B
6
6
X1XXXXXX
110B
7
7
1XXXXXXX
111B
Notes: This table indicates the range of row addresses in each masked segment. X is don’t care for a particular segment.
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MR18:19_(Reserved) (MA<7:0> = 012H- 013H)
MR#
MA<0:7>
Function
18~19
12H~13H
(Reserved)
OP<7:0>
Access OP7
OP6
OP5
OP4
OP3
OP2
OP1
OP0
(RFU)
RFU
MR20:31_(Do Not Use) (MA<7:0> = 014H- 01FH)
MR#
MA<0:7>
20~31
18H~1FH
OP<7:0>
Function
Access OP7
OP6
OP5
OP4
OP3
OP2
OP1
OP0
OP5
OP4
OP3
OP2
OP1
OP0
Reserved for NVM
Reserved for NVM
MR32_DQ Calibration Pattern A (MA<7:0> = 020H)
MR#
MA<0:7>
32
20H
OP<7:0>
Function
Access OP7
DQ calibration pattern A
OP6
R
Reads to MR32 return DQ calibration
pattern A
See “Data Calibration Pattern Description”
Read-only
MR40_DQ Calibration Pattern B(MA<7:0> = 028H)
MR#
MA<0:7>
40
OP<7:0>
28H
Function
Access OP7
DQ calibration pattern B
Reads to MR40 return DQ calibration
pattern B
Confidential
OP6
R
OP5
OP4
OP3
OP2
OP1
OP0
See “Data Calibration Pattern Description”
Read-only
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MR63_Reset (MA<7:0> = 03FH): MRW only
MR#
MA<0:7>
63
3FH
OP<7:0>
Function
Access OP7
Reset
OP6
OP5
OP4
W
Reset
OP3
OP2
OP1
OP0
X
Write-only
X
Notes: For additional information on MRW RESET, see “Mode Register Write Command” on Timing Spec.
Do Not Use and Reserved functions
MR#
MA<0:7>
33~39
21H~27H
(Do Not Use)
41~47
29H~2FH
(Do Not Use)
48~62
30H~3EH
(Reserved)
(RFU)
64~126
40H~7EH
(Reserved)
(RFU)
127
7FH
(Do Not Use)
128~190
80H~BEH
(Reserved)
191
BFH
(Do Not Use)
192~254
C0H~FEH
(Reserved)
255
FFH
(Do Not Use)
Confidential
Function
Access OP7
OP6
OP5
OP4
OP3
OP2
OP1
OP0
(RFU)
(RFU)
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LPDDR2-S4 SDRAM Truth Table
Operation or timing that is not specified is illegal, and after such an event, in order to guarantee proper operation, the
LPDDR2 device must be powered down and then restarted through the specified initialization sequence before normal
operation can continue.
Command Truth Table
SDR Command Pins
DDR CA pins (10)
CKE
CS_n CA0 CA1 CA2 CA3 CA4 CA5 CA6 CA7 CA8 CA9
SDRAM command
CK_t(n-1) CK_t(n)
MRW
H
H
L
MRR
H
H
L
Refresh
(per bank)11
H
H
L
Refresh
(all bank)
H
H
L
Enter
Self Refresh
H
L
L
Activate
(bank)
H
H
L
Write
(bank)
H
H
L
Read
(bank)
H
H
L
H
H
L
BST
H
H
L
Enter
Deep Power Down
H
L
L
NOP
H
H
L
Maintain
PD, SREF, DPD
(NOP)
L
L
L
Maintain
PD, SREF, DPD
(NOP)
Enter
Power Down
Exit
PD, SREF, DPD
Confidential
H
H
L
L
L
L
L
H
L
H
H
L
H
L
H
H
MA0 MA1 MA2 MA3 MA4 MA5
MA0 MA1 MA2 MA3 MA4 MA5
x
MA6 MA7
L
L
H
L
L
L
H
H
x
x
x
x
L
L
x
H
x
L
H
R8
R9
R10
R11
R12
BA0 BA1 BA2
R0
R1
R2
R3
R4
R5
R6
R7
H
L
L
C1
C2
3,4
RFU RFU
C3
C4
H
L
H
AP3,4
C3
C4
C5
C6
H
H
L
H
AB
C5
C6
RFU RFU
C7
C8
C1
C2
C7
R13
R14
BA0 BA1 BA2
C9
C10
C11
BA0 BA1 BA2
C8
C9
x
C10
C11
BA0 BA1 BA2
x
H
H
L
x
L
x
H
H
x
L
x
H
H
x
H
x
H
H
x
H
x
x
H
L
L
MA6 MA7 OP0 OP1 OP2 OP3 OP4 OP5 OP6 OP7
AP
Precharge
(bank)
NOP
L
CK
EDGE
x
x
x
x
x
x
x
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Notes:
1. All LPDDR2 commands are defined by states of CS_n(CS), CA0, CA1, CA2, CA3, and CKE at the rising edge of the
clock.
2. For LPDDR2 SDRAM, Bank addresses BA0, BA1, BA2 (BA) determine which bank is to be operated upon.
3. AP “high” during a READ or WRITE command indicates that an auto-precharge will occur to the bank associated with
the READ or WRITE command.
4. “x” means “H or L (but a defined logic level)”.
5. Self refresh exit and Deep Power Down exit are asynchronous.
6. VREF must be between 0 and VDDQ during Self Refresh and Deep Down operation.
7. CAxr refers to command/address bit “x” on the rising edge of clock.
8. CAxf refers to command/address bit “x” on the rising edge of clock.
9. CS_n(CS) and CKE are sampled at the rising edge of clock.
10. Per Bank Refresh is only allowed in devices with 8 banks.
11. The least-significant column address C0 is not transmitted on the CA bus, and is implied to be zero.
CKE Truth Table
*1
*1
Device Current State*3 CKEn-1 CKEn CS_n*2
Active
Power Down
Command n*4
Operation n*4
Device Next State
L
L
X
X
Maintain Active Power Down
Active Power Down
L
H
H
NOP
Exit Active Power Down
Active
L
L
X
X
Maintain Idle Power Down
Idle Power Down
L
H
H
NOP
Exit Idle Power Down
Idle
L
L
X
X
L
H
H
NOP
L
L
X
X
L
H
H
NOP
Exit Deep Power Down
Power On
L
L
X
X
Maintain Self Refresh
Self Refresh
L
H
H
NOP
Exit Self Refresh
Idle
H
L
H
NOP
H
L
H
NOP
H
L
L
H
L
L
Deep Power Down
H
L
H
NOP
H
H
Notes
6, 9
Idle Power Down
Resetting
Maintain
Resetting
Resetting Power Down
Power Down
Power Down
Exit Resetting Power Down
Deep Power Down
Maintain
Deep Power Down
Idle or
Resetting
6, 9
6, 9, 12
Deep Power Down
8
Self Refresh
Bank(s) Active
All Banks Idle
Resetting
Confidential
Enter
Active Power Down
Enter
Idle Power Down
Enter
Enter
Self-Refresh
Self Refresh
Enter
Deep Power Down
Enter
Resetting Power Down
7, 10
Active Power Down
Idle Power Down
Self Refresh
Deep Power Down
Resetting Power Down
Refer to the Command Truth Table
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Notes:
1. “CKEn” is the logic state of CKE at clock rising edge n; “CKEn-1” was the state of CKE at the previous clock edge.
2. “CS_n” is the logic state of CS_n at the clock rising edge n.
3. “Current state” is the state of the LPDDR2 device immediately prior to clock edge n.
4. “Command n” is the command registered at clock edge N, and “Operation n” is a result of “Command n".
5. All states and sequences not shown are illegal or reserved unless explicitly described elsewhere in this document.
6. Power Down exit time (tXP) should elapse before a command other than NOP is issued.
7. Self-Refresh exit time (tXSR) should elapse before a command other than NOP 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 twice during the tXSR time.
11. "X" means "Don't care".
12. Upon exiting Resetting Power Down, the device will return to the Idle state if tINIT5 has expired.
Current State Bank n - Command to Bank n
Current State
Any
Command
NOP
ACTIVATE
Idle
Row
Active
Reading
Writing
Operation
Next State
Continue previous operation
Current State
Select and activate row
NOTES
Active
Refresh (Per Bank)
Begin to refresh
Refreshing (Per Bank)
6
Refresh (All Bank)
Begin to refresh
Refreshing(All Bank)
7
MR Writing
7
MRW
Load value to Mode Register
Idle
MR Reading
MRR
Read value from Mode Register
Reset
Begin Device Auto-Initialization
Resetting
7, 8
Precharge
Deactivate row in bank or banks
Precharging
9, 15
Read
Select column, and start read burst
Reading
Write
Select column, and start write burst
Writing
MRR
Read value from Mode Register
Active
MR Reading
Precharge
Deactivate row in bank or banks
Precharging
Read
Select column, and start new read burst
Write
Select column, and start write burst
9
Reading
10, 11
Writing
10, 11, 12
BST
Read burst terminate
Active
13
Write
Select column, and start new write burst
Writing
10, 11
Read
Select column, and start read burst
Reading
10, 11, 14
BST
Write burst terminate
Active
13
7, 9
Power On
Reset
Begin Device Auto-Initialization
Resetting
Resetting
MRR
Read value from Mode Register
Resetting MR Reading
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 Power Down.
2. All states and sequences not shown are illegal or reserved.
3. Current State Definitions:
Idle: The bank or banks have been precharged, and tRP has been met.
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.
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Reading: A Read burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
Writing: A Write burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
4. The following states must not be interrupted by a command issued to the same bank. NOP commands or allowable
com-mands to the other bank should be issued on any clock edge occurring during these states.
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 Activate command and ends when tRCD is met. Once tRCD is met, the
bank will be in the ‘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.
5. The following states must not be interrupted by any executable command; NOP commands must be applied to each
pos-itive clock edge during these states.
Refreshing (Per Bank): starts with registration of an Refresh (Per Bank) command and ends when tRFCpb is met. Once
tRFCpb is met, the bank will be in an ‘idle’ state.
Refreshing (All Bank): starts with registration of an Refresh (All Bank) command and ends when tRFCab is met. Once
tRFCab is met, the device will be in an ‘all banks idle’ state.
Idle MR Reading: starts with the registration of a MRR command and ends when tMRR has been met. Once tMRR has
been met, the bank will be in the Idle state.
Resetting MR Reading: starts with the registration of a MRR command and ends when tMRR has been met. Once tMRR
has been met, the bank will be in the Resetting state.
Active MR Reading: starts with the registration of a MRR command and ends when tMRR has been met. Once tMRR
has been met, the bank will be in the Active state.
MR Writing: starts with the registration of a MRW command and ends when tMRW has been met. Once tMRW has been
met, the bank will be in the 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.
6. Bank-specific; requires that the bank is idle and no bursts are in progress.
7. Not bank-specific; requires that all banks are idle and no bursts are in progress.
8. Not bank-specific reset command is achieved through Mode Register Write command.
9. This command may or may not be bank specific. If all banks are being precharged, they must be in a valid state for
pre-charging.
10. A command other than NOP should not be issued to the same bank while a Read or Write burst with Auto Precharge
is enabled.
11. The new Read or Write command could be Auto Precharge enabled or Auto Precharge disabled.
12. A Write command may be applied after the completion of the Read burst; otherwise, a BST must be used to end the
Read prior to asserting a Write command.
13. Not bank-specific. Burst Terminate (BST) command affects the most recent read/write burst started by the most
recent Read/Write command, regardless of bank.
14. A Read command may be applied after the completion of the Write burst; otherwise, a BST must be used to end the
Write prior to asserting a Read command.
15. If a Precharge command is issued to a bank in the Idle state, tRP shall still apply.
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Current State Bank n - Command to Bank m
Current State of Command for
Bank n
Bank m
Any
Idle
Row Activating,
Active, or
Precharging
Reading
(Autoprecharge
disabled)
Any
Any command allowed to Bank m
-
18
Activate
Select and activate row in Bank m
Active
7
Read
Select column, and start read burst from Bank m
Write
Select column, and start write burst to Bank m
Current State of Bank m
Reading
8
Writing
8
Deactivate row in bank or banks
Precharging
9
MRR
Read value from Mode Register
Idle MR Reading or
Active MR Reading
10, 11, 13
BST
Read or Write burst terminate an ongoing
Read/Write from/to Bank m
Active
18
Read
Select column, and start read burst from Bank m
Write
Select column, and start write burst to Bank m
Precharge
Activate
Select and activate row in Bank m
Deactivate row in bank or banks
Read
Select column, and start read burst from Bank m
Write
Select column, and start write burst to Bank m
Activate
Select and activate row in Bank m
Deactivate row in bank or banks
Read
Select column, and start read burst from Bank m
Write
Select column, and start write burst to Bank m
Activate
Precharge
Writing with
Autoprecharge
NOTES
Bank m
Continue previous operation
Precharge
Reading with
Autoprecharge
Next State for
NOP
Precharge
Writing
(Autoprecharge
disabled)
Operation
Select and activate row in Bank m
Deactivate row in bank or banks
Read
Select column, and start read burst from Bank m
Write
Select column, and start write burst to Bank m
Activate
Select and activate row in Bank m
Precharge
Deactivate row in bank or banks
Power On
Reset
Resetting
MRR
Reading
8
Writing
8, 14
Active
Precharging
9
Reading
8, 16
Writing
8
Active
Precharging
9
Reading
8, 15
Writing
8, 14, 15
Active
Precharging
9
Reading
8, 15, 16
Writing
8, 15
Active
Precharging
9
Begin Device Auto-Initialization
Resetting
12, 17
Read value from Mode Register
Resetting MR Reading
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. All states and sequences not shown are illegal or reserved.
3. Current State Definitions:
Idle: the bank has been precharged, and tRP has been met.
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.
Reading: a Read burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
Writing: a Write burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
4. Refresh, Self-Refresh, and Mode Register Write commands may only be issued when all bank are idle.
5. A Burst Terminate (BST) command cannot be issued to another bank; it applies to the bank represented by the current
state only.
6. The following states must not be interrupted by any executable command; NOP commands must be applied during
each clock cycle while in these states:
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Idle MR Reading: starts with the registration of a MRR command and ends when tMRR has been met. Once tMRR has
been met, the bank will be in the Idle state.
Resetting MR Reading: starts with the registration of a MRR command and ends when tMRR has been met. Once tMRR
has been met, the bank will be in the Resetting state.
Active MR Reading: starts with the registration of a MRR command and ends when tMRR has been met. Once tMRR
has been met, the bank will be in the Active state.
MR Writing: starts with the registration of a MRW command and ends when tMRW has been met. Once tMRW has been
met, the bank will be in the Idle state.
7. tRRD must be met between Activate command to Bank n and a subsequent Activate command to Bank m.
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. This command may or may not be bank specific. If all banks are being precharged, they must be in a valid state for
pre-charging.
10. MRR is allowed during the Row Activating state (Row Activating starts with registration of an Activate command and
ends when tRCD is met.)
11. MRR is allowed during the Precharging state. (Precharging starts with registration of a Precharge command and
ends when tRP is met.
12. Not bank-specific; requires that all banks are idle and no bursts are in progress.
13. The next state for Bank m depends on the current state of Bank m (Idle, Row Activating, Precharging, or Active). The
reader shall note that the state may be in transition when a MRR is issued. Therefore, if Bank m is in the Row Activating
state and Precharging, the next state may be Active and Precharge dependent upon tRCD and tRP respectively.
14. A Write command may be applied after the completion of the Read burst, otherwise a BST must be issued to end the
Read prior to asserting a Write command.
15. Read with auto precharge enabled or a Write with auto precharge enabled may be followed by any valid command to
other banks provided that the timing restriction.
16. A Read command may be applied after the completion of the Write burst; otherwise, a BST must be issued to end
the Write prior to asserting a Read command.
17. Reset command is achieved through Mode Register Write command.
18. BST is allowed only if a Read or Write burst is ongoing.
Data Mask Truth Table
Name (Functional)
DM
DQs
Note
Write enable
L
Valid
1
Write inhibit
H
X
1
Notes:
1. Used to mask write data, provided coincident with the corresponding data.
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COMMAND Definitions and Timing Diagrams
Active
The Active command is issued by holding CS LOW, CA0 LOW, and CA1 HIGH at the rising edge of the clock. The bank
addresses BA0-BA2 are used to select the desired bank. The row addresses R0-R14 is used to determine which row in
the selected bank. The Active command must be applied before any Read or Write operation can be executed. The
LPDDR2 SDRAM can accept a read or write command at time tRCD after the active command is sent. Once a bank has
been active, it must be precharged before another Active command can be applied to the same bank. The bank active
and precharge times are defined as tRAS and tRP, respectively. The minimum time interval between two successive
ACTIVE commands on the same bank is determined by the RAS cycle time of the device (tRC). The minimum time interval between two successive ACTIVE commands on different banks is defined by tRRD.
Certain restriction on operation of the 8 bank devices must be observed. One for restricting the number of sequential
Active commands that can be issued and another for allowing more time for RAS precharge for a Precharge All command. The rules are as follows:
8-bank device Sequential Bank Activation Restriction : No more than 4 banks may be activated (or refreshed, in the
case of REFpb) in a rolling tFAW window. Converting to clocks is done by dividing tFAW[ns] by tCK[ns], and rounding up
to next integer value. As an example of the rolling window, if RU{ (tFAW / tCK) } is 10 clocks, and an activate command
is issued in clock N, no more than three further activate commands may be issued at or between clock N+1 and N+9.
REFpb also counts as bank-activation for the purposes of tFAW.
8 bank device Precharge All allowance: tRP for a Precharge All command for an 8 Bank device shall equal to tRPab,
which is greater than tRPpb.
Activate command cycle: Trcd=3, Trp=3, Trrd=2
Notes:
1. A Precharge-All command uses tRPab timing, while a Single Bank Precharge command uses tRPpb timing. In this
figure, Trp is used to denote either an All-bank Precharge or a Single Bank Precharge.
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Tfaw timing
Notes:
1. Exclusively for 8-bank devices. No more than 4 banks may be activated in a rolling Tfaw window.
Command Input Signal Timing Definition
Command Input Setup and Hold Timing
Notes:
1. Setup and hold conditions also apply to the CKE pin.
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Read and Write access modes
After a bank has been activated, a read or write cycle can be executed. This is accomplished by setting CS LOW, CA0
HIGH, and CA1 LOW at the rising edge of the clock. CA2 must also be defined at this time to determine whether the
access cycle is a read operation (CA2 HIGH) or a write operation (CA2 LOW).
The LPDDR2 SDRAM provides a fast column access operation. A single Read or Write Command will initiate a burst
read or write operation on successive clock cycles.
For LPDDR2-S4 devices, a new burst access must not interrupt the previous 4-bit burst operation, in case of BL=4 setting. In case of BL=8 and BL=16 settings, Reads may be interrupted by Reads, and Writes may be interrupted by Writes
provided that this occurs on even clock cycles after the Read or Write command and that tCCD is met. The minimum
CAS to CAS delay is defined by tCCD.
Burst Read
The Burst Read command is initiated by having CS LOW, CA0 HIGH, CA1 LOW and CA2 HIGH at the rising edge of the
clock. The command address bus inputs, CA5r-CA6r and CA1f-CA9f, determine the starting column address for the
burst. The Read Latency (RL) is defined from the rising edge of the clock on which the Read Command is issued to the
rising edge of the clock from which the tDQSCK delay is measured. The first valid datum is available RL * tCK +
tDQSCK + tDQSQ after the rising edge of the clock where the Read Command is issued. The data strobe output is
driven LOW tRPRE before the first rising valid strobe edge. The first bit of the burst is synchronized with the first rising
edge of the data strobe. Each subsequent data-out appears on each DQ pin edge aligned with the data strobe. The RL
is programmed in the mode registers. Timings for the data strobe are measured relative to the crosspoint of DQS and its
complement, DQS.
Data output (Read) timing (tDQSCKmax)
Notes:
1. Tdqsck can span multiple clock periods.
2. An effective Burst Length of 4 is shown.
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Data output (Read) timing (tDQSCKmin), BL=4
Burst Read: RL=5, BL=4, Tdqsck > Tck
Burst Read: RL=3, BL=8, Tdqsck < Tck
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Tdqsckdl timing : Tdqsckdl = |tDQSCKn ʹ tDQSCKm| within any 32ms rolling window
Notes:
1. tDQSCKDLmax is defined as the maximum of ABS(tDQSCKn - tDQSCKm) for any { tDQSCKn - tDQSCKm} pair
within any 32ms rolling window.
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Tdqsckdm timing : Tdqsckdm= |tDQSCKn ʹ tDQSCKm| within any 1.6us rolling window
Notes:
1. tDQSCKDMmax is defined as the maximum of ABS(tDQSCKn - tDQSCKm) for any { tDQSCKn - tDQSCKm} pair
within any 1.6us rolling window.
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Tdqsckds timing : Tdqsckds = |tDQSCKn ʹ tDQSCKm| within a consecutive burst within any 160ns
rolling window
Notes:
1. tDQSCKDSmax is defined as the maximum of ABS(tDQSCKn - tDQSCKm) for any { tDQSCKn - tDQSCKm} pair for
reads within a consecutive burst within any 160ns rolling window.
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Burst Read followed by burst write: RL=3, WL=1, BL=4
The minimum time from the burst READ command to the burst WRITE command is defined by the read latency (RL) and
the burst length (BL). Minimum READ-to-WRITE latency is RL + RU(Tdqsck(MAX)/Tck) + BL/2 + 1 - WL clock cycles.
Note that if a READ burst is truncated with a burst TERMINATE (BST) command, the effective burst length of the truncated READ burst should be used as “BL” to calculate the minimum READ-to-WRITE delay.
Seamless Burst Read: RL=3, BL=4, Tccd=2
The seamless burst READ operation is supported by enabling a READ command at every other clock cycle for BL = 4
operation, every fourth clock cycle for BL = 8 operation, and every eighth clock cycle for BL=16 operation. This operation
is supported as long as the banks are activated, whether the accesses read the same or different banks.
For LPDDR2-S4 devices, burst read can be interrupted by another read on even clock cycles after the Read command,
provided that tCCD is met. For LPDDR2-S2 devices, burst reads may be interrupted by other reads on any subsequent
clock, provided that tCCD is met.
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t
Read burst interrupt example: RL=3, BL=8, CCD=2
Notes:
1. Reads can only be interrupted by other reads or the BST command.
2. The effective burst length of the first read equals two times the number of clock cycles between the first read and the
interrupting read.
Burst Write
The burst WRITE command is initiated with CS LOW, CA0 HIGH, CA1 LOW, and CA2 LOW at the rising edge of the
clock. The command address bus inputs, CA5r-CA6r and CA1f-CA9f, determine the starting column address for the
burst. Write latency (WL) is defined from the rising edge of the clock on which the WRITE command is issued to the rising edge of the clock from which the Tdqss delay is measured. The first valid data must be driven WL x Tck + Tdqss from
the rising edge of the clock from which the WRITE command is issued. The data strobe signal (DQS) must be driven
LOW Twpre prior to data input. The burst cycle data bits must be applied to the DQ pins Tds prior to the associated edge
of the DQS and held valid until Tdh after that edge. Burst data is sampled on successive edges of the DQS until the 4-,
8-, or 16-bit burst length is completed. After a burst WRITE operation, Twr must be satisfied before a PRECHARGE
command to the same bank can be issued.
Pin input timings are measured relative to the cross point of DQS and its complement, DQS.
Data input (Write) timing
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Burst write: WL=1, BL=4
Burst write followed by burst read: RL=3, WL=1, BL=4
Notes:
1. The minimum number of clock cycles from the burst write command to the burst read command for any bank is [WL +
1 + BL/2 + RU (Twtr / Tck) ].
2. Twtr starts at the rising edge of the clock after the last valid input datum.
3. If a write burst is truncated with a Burst Terminate (BST) command, the effective burst length of the truncated write
burst should be used as “BL” to calculate the minimum write to read delay.
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Seamless Burst write: WL=1, BL=4, Tccd=2
Notes:
1. The seamless burst write operation is supported by enabling a write command every other clock for BL=4 operation,
every four clocks for BL=8 operation, or every eight clocks for BL=16 operation. This operation is allowed regardless of
same or different banks as long as the banks are activated.
Write burst interrupt timing: WL=1, BL=8, Tccd=2
Notes:
1. WRITEs can only be interrupted by other WRITEs or the BST command.
2. For LPDDR2-S4 devices, write burst interrupt function is only allowed on burst of 8 and burst of 16.
3. For LPDDR2-S4 devices, write burst interrupt may only occur on even clock cycles after the previous write commands, provided that Tccd(min) is met.
4. Write burst interruption is allowed to any bank inside DRAM.
5. Write burst with Auto-Precharge is not allowed to be interrupted.
6. The effective burst length of the first WRITE equals two times the number of clock cycles between the first WRITE
and the interrupting WRITE.
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Burst Terminate
The BST command is initiated with CS LOW, CA0 HIGH, CA1 HIGH, CA2 LOW, and CA3 LOW at the rising edge of the
clock. A BST command can only be issued to terminate an active READ or WRITE burst. Therefore, a BST command
can only be issued up to and including BL/2 - 1 clock cycles after a READ or WRITE command. The effective burst
length of a READ or WRITE command truncated by a BST command is as follows:
Effective burst length = 2 x (number of clock cycles from the READ or WRITE command to the BST command).
If a READ or WRITE burst is truncated with a BST command, to calculate the minimum READ-to-WRITE or WRITE-toREAD delay, the effective burst length of the truncated burst should be used as the value for BL.
The BST command only affects the most recent READ or WRITE command. The BST command truncates an ongoing
READ burst RL x Tck + Tdqsck + Tdqsq after the rising edge of the clock where the BST command is issued. The BST
command truncates an on-going write burst WL x Tck + Tdqss after the rising edge of the clock where the BST command is issued.
For LPDDR2-S4 devices, the 4-bit prefetch architecture enables BST command assertion on even clock cycles following
a WRITE or READ command. The effective burst length of a READ or WRITE command truncated by a BST command
is thus an integer multiple of 4.
Burst Write truncated by BST: WL=1, BL=16
Notes:
1. The BST command truncates an ongoing write burst WL * tCK + tDQSS after the rising edge of the clock where the
Burst Terminate command is issued.
2. For LPDDR2-S4 devices, BST can only be issued an even number of clock cycles after the Write command.
3. Additional BST commands are not allowed after T4, and may not be issued until after the next Read or Write command.
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Burst Read truncated by BST: RL=3, BL=16
Notes:
1. The BST command truncates an ongoing read burst RL * tCK + tDQSCK + tDQSQ after the rising edge of the clock
where the Burst Terminate command is issued.
2. For LPDDR2-S4 devices, BST can only be issued an even number of clock cycles after the Write command.
3. Additional BST commands are not allowed after T4, and may not be issued until after the next Read or Write command.
Write data Mask
One write data mask (DM) pin for each data byte (DQ) will be supported on LPDDR2 devices, consistent with the implementation on LPDDR SDRAMs. Each data mask (DM) may mask its respective data byte (DQ) for any given cycle of the
burst. Data mask has identical timings on write operations as the data bits, though used as input only, is internally
loaded identically to data bits to insure matched system timing.
Data Mask Timing
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Write data mask: WL=2, BL=4, second DQ masked
Notes:
1. For the data mask function, WL=2, BL=4 is shown; the second data bit is masked.
Precharge
The Precharge command is used to precharge or close a bank that has been activated. The Precharge command is initiated by having CS LOW, CA0 HIGH, CA1 HIGH, CA2 LOW, and CA3 HIGH at the rising edge of the clock. The Precharge Command can be used to precharge each bank independently or all banks simultaneously. For 4-bank devices,
the AB flag, and the bank address bits, BA0 and BA1, are used to determine which bank(s) to precharge. For 8-bank
devices, the AB flag, and the bank address bits, BA0, BA1, and BA2, are used to determine which bank(s) to precharge.
The bank(s) will be available for a subsequent row access tRPab after an All-Bank Precharge command is issued and
tRPpb after a Single-Bank Precharge command is issued.
In order to ensure that 8-bank devices do not exceed the instantaneous current supplying capability of 4-bank devices,
the Row Precharge time (tRP) for an All-Bank Precharge for 8-bank devices (tRPab) will be longer than the Row Precharge time for a Single-Bank Precharge (tRPpb). For 4-bank devices, the Row Precharge time (tRP) for an All-Bank
Precharge (tRPab) is equal to the Row Precharge time for a Single-Bank Precharge (tRPpb).
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Bank selection for Precharge by address bits
AB (CA4r)
BA2 (CA9r)
BA1 (CA8r)
BA0 (CA7r)
Precharged Bank(s)
4-bank device
Precharged Bank(s)
8-bank device
0
0
0
0
Bank 0 only
Bank 0 only
0
0
0
1
Bank 1 only
Bank 1 only
0
0
1
0
Bank 2 only
Bank 2 only
0
0
1
1
Bank 3 only
Bank 3 only
0
1
0
0
Bank 0 only
Bank 4 only
0
1
0
1
Bank 1 only
Bank 5 only
0
1
1
0
Bank 2 only
Bank 6 only
0
1
1
1
Bank 3 only
Bank 7 only
1
DON’T CARE
DON’T CARE
All Banks
All Banks
DON’T CARE
Burst Read followed by precharge
For the earliest possible precharge, the precharge command may be issued BL/2 clock cycles after a Read command. A
new bank active (command) may be issued to the same bank after the Row Precharge time (tRP). A precharge command can not be issued until after tRAS is satisfied.
For LPDDR2-S4 devices, the minimum Read to Precharge spacing has also to satisfy a minimum analog time from the
rising cloak edge that initiates the last 4-bit precharge of a Read command. This time is called tRTP (Read to Precharge). For LPDDR2-S4 devices, tRTP begins BL/2 - 2 clock cycles after the Read command. If the burst is truncated
by a BST command, the effective “BL” ahsll be used to calculate when tRTP begins.
Burst Read followed by Precharge: RL=3, BL=8, RU( tRTP(min)/tCK)=2
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t
t
Burst Read followed by Precharge: RL=3, BL=4, RU( RTP(min)/ CK) = 3
Burst Write followed by precharge
For write cycles, a delay must be satisfied from the time of the last valid burst input data until the Precharge command
may be issued. This delay is known as the write recovery time (tWR) referenced from the completion of the burst write to
the Precharge command. No Precharge command to the same bank should be issued prior to the tWR delay.
LPDDR2-S2 devices write data to the array in prefetch pairs (prefetch = 2) and LPDDR2-S4 devices write data to the
array in prefetch quadruples (prefetch = 4). The beginning of an internal write operation may only begin after a prefetch
group has been completely. Therefore, the write recovery time (tWR) starts different boundaries for LPDDR2-S2 and
LPDDR2-S4 devices.
For LPDDR2-S2 devices, minimum Write to Precharge command spacing to the same bank is WL + RU(BL/2) + 1 +
RU(tWR/tCK) clock cycles. For LPDDR2-S4 devices, minimum Write to Precharge command spacing to the same bank
is WL + BL/2 + 1+ RU (tWR/tCK) clock cycles. For an untruncated burst, BL is the value from the Mode Register. For a
truncated burst, BL is the effective burst length.
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Burst Write followed by Precharge: WL=1, BL=4
Auto Precharge
Before a new row in an active bank can be opened, the active bank must be precharged using either the Precharge
command or the auto-precharge function. When a Read or a Write command is given to the LPDDR2 SDRAM, the AP
bit (CA0f) may be set to allow the active bank to automatically begin precharge at the earliest possible moment during
the burst read or write cycle. If AP is LOW when the Read or Write command is issued, the normal Read or Write burst
operation is executed and the bank remains active at the completion of the burst. If AP is HIGH when the Read or Write
command is issued, then the auto-precharge function is engaged. This feature allows the precharge operation to be partially or completely hidden during burst read cycles (dependent upon Read or Write latency) thus improving system performance for random data access.
Burst Read with Auto Precharge
If AP (CA0f) is HIGH when a Read Command is issued, the Read with Auto-Precharge function is engaged. LPDDR2S4 devices start an Auto-Precharge operation on the rising edge of the clock BL/2 or BL/2 - 2 + RU(tRTP/tCK) clock
cycles later than the Read with AP command, whichever is greater.
A new bank Activate command may be issued to the same bank if both of the following two conditions are satisfied
simultaneously:
The RAS precharge time (tRP) has been satisfied from the clock at which the auto-precharge begins.
The RAS cycle time (tRC) from the previous bank activation has been satisfied.
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t
t
Burst Read with Auto-Precharge: RL=3, BL=4, RU( RTP(min)/ CK)=2
Burst Write with Auto Precharge
If AP (CA0f) is HIGH when a Write Command is issued, the Write with Auto-Precharge function is engaged. The
LPDDR2 SDRAM starts an Auto-precharge operation on the rising edge which is Twr cycles after the completion of the
burst write.
A new bank Activate command may be issued to the same bank if both of the following two conditions are satisfied:
The RAS precharge time (Trp) has been satisfied from the clock at which the auto-precharge begins.
The RAS cycle time (Trc) from the previous bank activation has been satisfied.
Burst Write with Auto-Precharge: WL=1, BL=4
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LPDDR2-S4: Precharge & Auto Precharge clarification
From
Command
Read
BST
(for Reads)
Read w/AP
Minimum Delay between
”From Command” to “To Command”
Unit
Notes
Precharge (to same Bank as Read)
BL/2 + max(2, RU(tRTP/tCK)) - 2
clks
1
Precharge All
BL/2 + max(2, RU(tRTP/tCK)) - 2
clks
1
Precharge (to same Bank as Read)
1
clks
1
Precharge All
1
clks
1
Precharge (to same Bank as Read w/AP)
BL/2 + max(2, RU(tRTP/tCK)) - 2
clks
1,2
Precharge All
BL/2 + max(2, RU(tRTP/tCK)) - 2
clks
1
Activate (to same Bank as Read w/AP)
BL/2 + max(2, RU(tRTP/tCK)) - 2
+ RU(tRPpb/tCK)
clks
1
Illegal
clks
3
RL + BL/2+ RU(tDQSCKmax/tCK) - WL + 1
clks
3
Read or Read w/AP (same bank)
Illegal
clks
3
Read or Read w/AP (different bank)
BL/2
clks
3
Precharge (to same Bank as Write)
WL + BL/2 + RU(tWR/tCK) + 1
clks
1
Precharge All
WL + BL/2 + RU(tWR/tCK) + 1
clks
1
Precharge (to same Bank as Write)
WL + RU(tWR/tCK) + 1
clks
1
Precharge All
WL + RU(tWR/tCK) + 1
clks
1
Precharge (to same Bank as Write w/AP)
WL + BL/2 + RU(tWR/tCK) + 1
clks
1
Precharge All
WL + BL/2 + RU(tWR/tCK) + 1
clks
1
Activate (to same Bank as Write w/AP)
WL + BL/2 + RU(tWR/tCK) + 1
+ RU(tRPpb/tCK)
clks
1
Write or Write w/AP (same bank)
Illegal
clks
3
Write or Write w/AP (different bank)
BL/2
clks
3
Read or Read w/AP (same bank)
Illegal
clks
3
WL + BL/2 + RU(tWTR/tCK) + 1
clks
3
Precharge (to same Bank as Precharge)
1
clks
1
Precharge All
1
clks
1
Precharge
1
clks
1
Precharge All
1
clks
1
To Command
Write or Write w/AP (same bank)
Write or Write w/AP (different bank)
Write
BST
(for Writes)
Write w/AP
Read or Read w/AP (different bank)
Precharge
Precharge
All
Notes:
1. For a given bank, the precharge period should be counted from the latest precharge command, either one bank precharge or precharge all, issued to that bank. The precharge period is satisfied after tRP depending on the latest precharge command issued to that bank.
2. Any command issued during the minimum delay time as specified above table is illegal.
3. After Read with AP, seamless read operations to different banks are supported. After Write with AP, seamless write
operations to different banks are supported. Read w/AP and Write a/AP may not be interrupted or truncated.
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Refresh Command
The Refresh Command is initiated by having CS LOW, CA0 LOW, CA1 LOW, and CA2 HIGH at the rising edge of clock.
Per Bank Refresh is initiated by having CA3 LOW at the rising edge of the clock and All Bank Refresh is initiated by having CA3 HIGH at the rising edge of clock. Per Bank Refresh is only allowed in devices with 8 banks.
A Per Bank Refresh Command, REFpb performs a refresh operation to the bank which is scheduled by the bank counter
in the memory device. The bank sequence of Per Bank Refresh is fixed to be a sequential round-robin: “0-1-2-3-4-5-6-70-1-...”. The bank count is synchronized between the controller and the SDRAM upon issuing a RESET command or at
every exit from self refresh, by resetting bank count to zero. The bank addressing for the Per Bank Refresh count is the
same as established in the single-bank Precharge command.
A bank must be idle before it can be refreshed. It is the responsibility of the controller to track the bank being refreshed
by the Per Bank Refresh command. The REFpb command may not be issued to the memory until the following conditions are met:
- tRFCab has been satisfied after the prior REFab command.
- tRFCpb has been satisfied after the prior REFpb command.
- Trp has been satisfied after the prior Precharge command to that given bank.
Trrd has been satisfied after the prior ACTIVATE command (if applicable, for example after activating a row in a different
bank than affected by the REFpb command. The target bank is inaccessible during the Per Bank Refresh cycle
(tRFCpb), however other banks within the device are accessible and may be addressed during the Per Bank Refresh
cycle. During the REFpb operation, any of the banks other than the one being refreshed can be maintained in active
state or accessed by a read or a write command.
When the Per Bank Refresh cycle has completed, the affected bank will be in the idle state. As shown in the table, after
issuing REFpb:
- tRFCpb must be satisfied before issuing a REFab command.
- tRFCpb must be satisfied before issuing an ACTIVE command to a same bank.
- Trrd must be satisfied before issuing an ACTIVE command to a different bank.
- tRFCpb must be satisfied before issuing another REFpb command.
An All Bank Refresh command, REFab performs a refresh operation to all banks. All banks have to be in idle state when
REFab is issued (for instance, by Precharge All Bank command). REFab also synchronizes the bank count between the
controller and the SDRAM to zero. As shown in the table, the REFab command may not be issued to the memory until
the following conditions have been met:
- tRFCab has been satisfied after the prior REFab command.
- tRFCpb has been satisfied after the prior REFpb command.
- Trp has been satisfied after the prior Precharge commands.
When the All Bank Refresh cycle has completed, all banks will be in the idle state. As shown in the table, after issuing
REFab:
- the tRFCab latency must be satisfied before issuing an ACTIVATE command.
- the tRFCab latency must be satisfied before issuing a REFab or REFpb command.
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Command Scheduling Separations related to Refresh
Symbol
minimum delay from
tRFCab
to
REFab
Notes
REFab
Activate cmd to any bank
REFpb
tRFCpb
REFpb
REFab
Activate cmd to same bank as REFpb
REFpb
tRRD
REFpb
Activate cmd to different bank than REFpb
Activate
REFpb affecting an idle bank (different bank than Activate)
1
Activate cmd to different bank than prior Activate
Notes:
1. A bank must be in the Idle state before it is refreshed. Therefore, after Activate, REFab is not allowed and REFpb is
allowed only if it affects a bank which is in the Idle state.
Refresh Requirement
(1) Minimum number of Refresh commands:
LPDDR2 requires a minimum number, R, of REFRESH (REFab) commands within any rolling refresh window (Trefw =
32 ms @ MR4[2:0] = 011 or TC =< 85’C). For actual values per density, and the resulting average refresh interval (Trefi)
is given in the table below.
Symbol
Parameter
4Gb(Single Die)
8Gb(Dual Dies)
Unit
Number of banks
8
tREFW
Refresh window: TCASE =< 85’C
32
ms
tREFW
Refresh window: 85’C < TCASE =< 105’C
8
ms
R
Required number of REFRESH commands (MIN)
8192
8192
tREFI
Average time between REFRESH commands (for
reference only) TCASE <= 85’C
3.9
3.9
us
0.4875
0.4875
us
tREFIpb
tRFCab
Refresh cycle time
130
130
ns
tRFCpb
Per-bank REFRESH cycle time
60
60
ns
tREFBW
Burst REFRESH window = 4 x 8 x tRFCab
4.16
4.16
us
And see Mode Register 4 information for Trefw and Trefi refresh multipliers at different MR4 settings.
For devices supporting per-bank REFRESH, a REFab command can be replaced by a full cycle of eight REFpb commands.
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(2) Burst Refresh limitation:
To limit maximum current consumption, a maximum of 8 REFab commands may be issued in any rolling Trefbw
(Trefbw = 4 x 8 x tRFCab). This condition does not apply if REFpb commands are used.
(3) Refresh Requirements and Self-Refresh:
If any time within a refresh window is spent in Self-Refresh Mode, the number of required Refresh commands in this particular window is reduced to:
R*=R -RU{Tsrf/Trefi} =R-RU{R*Tsrf/Trefw }, where RU stands for the round-up function.
LPDDR2 S4: Definition of Tsrf
NOTE: Above examples are several cases on how to Tsrf is calculated
1. (Example A): Time in self refresh mode is fully enclosed in the refresh window (Trefw).
2. (Example B): At self refresh entry.
3. (Example C): At self refresh exit.
4. (Example D): Several intervals in self refresh during one Trefw interval. In this example, Tsrf = Tsrf1 + Tsrf2.
The LPDDR2 devices provide significant flexibility in scheduling REFRESH commands as long as the boundary conditions are met. In the most straightforward implementations, a REFRESH command should be scheduled every Trefi. In
this case, self refresh can be entered at any time.
Users may choose to deviate from this regular refresh pattern, for example, to enable a period where no refreshes are
required. In the extreme (e.g., LPDDR2-S4 1Gb), the user can choose to issue a refresh burst of 4096 REFRESH commands at the maximum supported rate (limited by Trefbw), followed by an extended period without issuing any
REFRESH commands, until the refresh window is complete. The maximum supported time without REFRESH commands is calculated as follows: Trefw - (R/8) x Trefbw = Trefw - R x 4 x tRFCab.
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For example, a 1Gb LPDDR2-S4 device at TC =< 85’C can be operated without REFRESH commands up to 32ms 4096 x 4 x 130ns ~ 30 ms. Both the regular and the burst/pause patterns can satisfy refresh requirements if they are
repeated in every 32ms window. It is critical to satisfy the refresh requirement in every rolling refresh window during
refresh pattern transitions. The supported transition from a burst pattern to a regular distributed pattern. If this transition
occurs immediately after the burst refresh phase, all rolling Trefw intervals will meet the minimum required number of
refreshes.
A non-supported transition - In this example, the regular refresh pattern starts after the completion of the pause phase of
the burst/pause refresh pattern. For several rolling Trefw intervals, the minimum number of REFRESH commands is not
satisfied.
Understanding this pattern transition is extremely important, even when only one pattern is employed. In self refresh
mode, a regular distributed-refresh pattern must be assumed. It is recommended entering self refresh mode immediately following the burst phase of a burst/pause refresh pattern; upon exiting self refresh, begin with the burst phase.
Regular, Distributed REFRESH Pattern
Notes:
1. Compared to repetitive burst REFRESH with subsequent REFRESH pause.
2. As an example, in a 1Gb LPDDR2-S4 device at TC =< 85’C, the distributed refresh pattern has one REFRESH command per 7.8us; the burst refresh pattern has one refresh command per 0.52us, followed by ~30ms without any
REFRESH command.
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Supported Transition from Repetitive Burst REFRESH
Notes:
1. Shown with subsequent REFRESH pause to regular, distributed-refresh pattern.
2. As an example, in a 1Gb LPDDR2-S4 device at TC =< 85’C, the distributed refresh pattern has one REFRESH command per 7.8us; the burst refresh pattern has one refresh command per 0.52us, followed by ~30ms without any
REFRESH command.
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Recommended Self Refresh Entry and Exit
Notes:
1. In conjunction with a burst/pause refresh pattern.
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All Bank Refresh Operation
Per-Bank Refresh Operation
N
Notes:
1. In the beginning of this example, the REFpb bank is pointing to Bank 0.
2. Operations to other banks than the bank being refreshed are allowed during the tREFpb period.
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Self Refresh Operation
The Self Refresh command can be used to retain data in the LPDDR2 SDRAM, even if the rest of the system is powered
down. When in the Self Refresh mode, the LPDDR2 SDRAM retains data without external clocking. The LPDDR2
SDRAM device has a built-in timer to accommodate Self Refresh operation. The Self Refresh Command is defined by
having CKE LOW, CS LOW, CA0 LOW, CA1 LOW, and CA2 HIGH at the rising edge of the clock. CKE must be HIGH
during the previous clock cycle. A NOP command must be driven in the clock cycle following the power-down command.
Once the command is registered, CKE must be held LOW to keep the device in Self Refresh mode.
LPDDR2-S4 devices can operate in Self Refresh in both the Standard or Extended Temperature Ranges. LPDDR2-S4
devices will also manage Self Refresh power consumption when the operating temperature changes, lower at low temperature and higher at high temperature.
Once the LPDDR2 SDRAM has entered Self Refresh mode, all of the external signals except CKE, are “don’t care”. For
proper self refresh operation, power supply pins (VDD1, VDD2, and VDDCA) must be at valid levels. VDDQ may be
turned off during Self-Refresh. Prior to exiting Self-Refresh, VDDQ must be within specified limits. VrefQD and VrefCA
may be at any level within minimum and maximum levels. However prior to exiting Self-Refresh, VrefDQ and VrefCA
must be within specified limits. The SDRAM initiates a minimum of one all-bank refresh command internally within Tckesr period, once it enters Self Refresh mode. The clock is internally disabled during Self Refresh Operation to save
power. The minimum time that the LPDDR2 SDRAM must remain in Self Refresh mode is Tckesr. The user may change
the external clock frequency or halt the external clock one clock after Self Refresh entry is registered; however, the clock
must be restarted and stable before the device can exit Self Refresh operation.
The procedure for exiting Self Refresh requires a sequence of commands. First, the clock shall be stable and within
specified limits for a minimum of 2 clock cycles prior to CKE going back HIGH. Once Self Refresh Exit is registered, a
delay of at least Txsr must be satisfied before a valid command can be issued to the device to allow for any internal
refresh in progress. CKE must remain HIGH for the entire Self Refresh exit period Txsr for proper operation except for
self refresh re-entry. NOP commands must be registered on each positive clock edge during the Self Refresh exit interval Txsr.
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, it is required that at least one Refresh command
(8 per-bank or 1 all-bank) is issued before entry into a subsequent Self Refresh.
Self Refresh Operation
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Notes:
1. Input clock frequency may be changed or stopped during self-refresh, provided that upon exiting self-refresh, a minimum of
2 clocks (Tinit2) of stable clock are provided and the clock frequency is between the minimum and maximum frequency for the
particular speed grade.
2. Device must be in the “All banks idle” state prior to entering Self Refresh mode.
3. Txsr begins at the rising edge of the clock after CKE is driven HIGH.
4. A valid command may be issued only after Txsr is satisfied. NOPs shall be issued during Txsr.
Partial Array Self-Refresh: Bank Masking
LPDDR2-S4 SDRAM has 4 or 8 banks. For LPDDR2-S4 devices, 64Mb to 512Mb LPDDR2 SDRAM has 4 banks, while
1Gb and higher density has 8. Each bank of LPDDR2 SDRAM can be independently configured whether a self refresh
operation is taking place. One mode register unit of 8 bits accessible via MRW command is assigned to program the
bank masking status of each bank up to 8 banks. For bank masking bit assignments, see Mode Register 16.
The mask bit to the bank controls a refresh operation of entire memory within the bank. If a bank is masked via MRW, a
refresh operation to entire bank is not blocked and data retention by a bank is not guaranteed in self refresh mode. To
enable a refresh operation to a bank, a coupled mask bit has to be programmed, “unmasked”. When a bank mask bit is
unmasked, the array space being refreshed within that bank is determinate by the programmed status of the segment
mask bit.
Partial Array Self-Refresh: Segment Masking
Segment Programming segment mask bits is similar to programming bank mask bits. For densities 1Gb and higher, 8
segments are used for masking. Mode register 17 is used for programming segment mask bits up to 8 bits. For densities
less than 1Gb, segment masking is not supported.
When the mask bit to an address range (represented as a segment) is programmed as “masked” a REFRESH operation
to that segment is blocked. Conversely, when a segment mask bit to an address range is unmasked, refresh to that segment is enabled. A segment-masking scheme can be used in place of or in combination with a bank masking scheme in
LPDDR2-S4 SDRAM. Each segment-mask bit setting is applied across all banks.
Segment Mask
Bnak 0 Bank 1 Bank 2 Bank 3 Bnak 4 Bank 5 Bank 6 Bank 7
(MR17)
Bank Mask
(MR16)
Segment 0
Segment 1
Segment 2
Segment 3
Segment 4
Segment 5
Segment 6
Segment 7
0
0
0
1
0
0
0
0
1
M
M
1
M
M
M
M
M
M
M
M
0
0
0
0
0
M
M
M
M
M
M
M
M
M
M
1
M
M
M
M
M
M
M
M
Example of Bank and Segment Masking use in LPDDR2-S4 devices
Notes:
1. This table illustrates an example of an 8-bank LPDDR2-S4 device, when a refresh operation to bank 1 and bank 7, as
well as segment 2 and segment 7 are masked.
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Mode Register Read Command
The Mode Register Read command is used to read configuration and status data from mode registers for LPDDR
SDRAM. The Mode Register Read (MRR) command is initiated by having CS LOW, CA0 LOW, CA1 LOW, CA2 LOW,
and CA3 HIGH at the rising edge of the clock. The mode register is selected by {CA1f-CA0f, CA9r-CA4r}. The mode register contents are available on the first data beat of DQ0-DQ7, RL * Tck + Tdqsck + Tdqsq after the rising edge of the
clock where the Mode Register Read Command is issued. Subsequent data beats contain valid, but undefined content,
except in the case of the DQ Calibration function DQC, where subsequent data beats contain valid content as described
in “DQ Calibration”. All DQS shall be toggled for the duration of the Mode Register Read burst. The MRR command has
a burst length of four. The Mode Register Read operation (consisting of the MRR command and the corresponding data
traffic) shall not be interrupted. The MRR command period (Tmrr) is 2 clock cycles. Mode Register Reads to reserved
and write-only registers shall return valid, but undefined content on all data beats and DQS shall be toggled.
Mode Register Read timing example: RL=3, Tmrr=2
Notes:
1. Mode Register Read has a burst length of four.
2. Mode Register Read operation shall not be interrupted.
3. MRRs to DQ calibration registers MR32 and MR40 are described in “DQ Calibration”.
4. Only the NOP command is supported during Tmrr.
5. Mode register data is valid only on DQ[7:0] on the first beat. Subsequent beats contain valid but undefined data.
DQ[MAX:8] contain valid but undefined data for the duration of the MRR burst.
6. Minimum Mode Register Read to write latency is RL+RU(Tdqsck,max/Tck)+4/2+1-WL clock cycles.
7. Minimum Mode Register Read to Mode Register Write Latency is RL+RU(Tdqsck,max/Tck)+4/2+1 clock cycles.
After a prior READ command, the MRR command must not be issued earlier than BL/2 clock cycles, or WL + 1 + BL/2 +
RU(Twtr/Tck) clock cycles after a prior WRITE command, as READ bursts and WRITE bursts must not be truncated by
MRR. Note that if a READ or WRITE burst is truncated with a BST command, the effective burst length of the truncated
burst should be used for the value BL.
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Read to MRR timing example: RL=3, Tmrr=2
Notes:
1. The minimum number of clocks from the burst read command to the Mode Register Read command is BL/2.
2. Only the NOP command is supported during Tmrr.
Burst Write Followed by MRR: RL=3, WL=1, BL=4
Notes:
1. The minimum number of clock cycles from the burst write command to the Mode Register Read command is [WL + 1
+ BL/2 + RU( Twtr/Tck)].
2. Only the NOP command is supported during Tmrr.
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Temperature Sensor
LPDDR2 devices feature a temperature sensor whose status can be read from MR4. This sensor can be used to determine an appropriate refresh rate, determine whether AC timing derating is required in the extended temperature range,
and/or monitor the operating temperature. Either the temperature sensor or the device operating temperature can be
used to determine if operating temperature requirements are being met.
Temperature sensor data may be read from MR4 using the Mode Register Read protocol.
When using the temperature sensor, the actual device case temperature may be higher than the operating temperature
specification that applies for the standard or extended temperature ranges. For example, TCASE could be above 85’C
when MR4[2:0] equals 011B.
To assure proper operation using the temperature sensor, applications must accommodate the specifications shown in
bellow.
Parameter
System Temperature Gradient
MR4 Read Interval
Temperature Sensor Interval
System Response Delay
Device Temperature Margin
Symbol
Max/Min
Value
Unit
Notes
TempGradient
Max
System Dependent
C/s
Maximum temperature gradient experienced by the memory device at the temperature of interest over a range of 2’C.
ReadInterval
Max
System Dependent
ms
Time period between MR4 READs from
the system.
tTSI
Max
32
ms
Maximum delay between internal updates
of
SysRespDelay
Max
System Dependent
ms
Maximum response time from an MR4
READ to the system response.
TempMargin
Max
2
C
Margin above maximum temperature to
support controller response.
These devices accommodate the 2 degree Celsius temperature margin between the point at which the device temperature enters the extended temperature range and point at which the controller re-configures the system accordingly. To
determine the required MR4 polling frequency, the system must use the maximum TempGradient and the maximum
response time of the system using the following equation:
TempGradient x (ReadInterval + tTSI + SysRespDelay) =< 2’C
For example, if TempGradient is 10’C/s and the SysRespDelay is 1ms:
10’C/s x (ReadInterval + 32ms + 1ms) =< 2’C
In this case, ReadInterval shall be no greater than 167 ms.
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Temp Sensor Timing
DQ Calibration
LPDDR2 devices feature a DQ calibration function that outputs one of two predefined system-timing calibration patterns.
MRR to MR32 (pattern A) or MRR to MR40 (pattern B) will return the specified pattern on DQ0 and DQ8 for x16 devices
and DQ0, DQ8, DQ16, and DQ24 for x32 devices. For x16 devices, DQ[7:1] and DQ[15:9] drive the same information as
DQ0 during the MRR burst. For x32 devices, DQ[7:1], DQ[15:9], DQ[23:17], and DQ[31:25] drive the same information
as DQ0 during the MRR burst. MRR DQ calibration commands can occur only in the idle state.
Data Calibration Pattern Description
Bit Time 0
Bit Time 1
Bit Time 2
Bit Time 3
Pattern “A” (MR32)
1
0
1
0
Pattern “B” (MR40)
0
0
1
1
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t
DQ MR32 and MR40 DQ Calibration timing, example: RL=3, MRR=2
Notes: Only the NOP command is supported during Tmrr. Mode Register Read has BL4 and shall not be interrupted.
Mode Register Write Command
The MRW command is used to write configuration data to mode registers. The MRW command is initiated with CS LOW,
CA0 LOW, CA1 LOW, CA2 LOW, and CA3 LOW at the rising edge of the clock. The mode register is selected by CA1fCA0f, CA9r-CA4r. The data to be written to the mode register is contained in CA9f-CA2f. The MRW command period is
defined by Tmrw. Mode register WRITEs to read-only registers have no impact on the functionality of the device.
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Mode Register Write timing, example: RL=3, Tmrw=5
Notes:
1. Only the NOP command is supported during Tmrw.
2. At time Ty, the device is in the idle state.
The MRW can only be issued when all banks are in the idle precharge state. One method of ensuring that the banks are
in this state is to issue a PRECHARGE-ALL command.
Truth Table for Mode Register Read (MRR) and Mode Register Write (MRW)
Current Stat
All Banks idle
Bank(s) Active
Command
Intermediate State
Next State
MRR
Mode Register Reading (All Banks idle)
All Banks idle
MRW
Mode Register Writing (All Banks idle)
All Banks idle
MRW (Reset)
Restting (Device Auto-Init)
All Banks idle
MRR
Mode Register Reading (Bank(s) idle)
Bank(s) Active
MRW
Not Allowed
Not Allowed
MRW (Reset)
Not Allowed
Not Allowed
Mode Register Write Reset (MRW Reset)
The MRW RESET command brings the device to the device auto-initialization (resetting) state in the power-on initialization sequence. The MRW RESET command can be issued from the idle state. This command resets all mode registers
to their default values. Only the NOP command is supported during Tinit4. After MRW RESET, boot timings must be
observed until the device initialization sequence is complete and the device is in the idle state. Array data is undefined
after the MRW RESET command.
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Mode Register Write ZQ Calibration command
The MRW command is used to initiate the ZQ calibration command. This command is used to calibrate the output driver
impedance across process, temperature, and voltage. LPDDR2-S4 devices support ZQ calibration.
There are four ZQ calibration commands and related timings: Tzqinit, Tzqreset, Tzqcl, and Tzqcs. Tzqinit is for initialization calibration; Tzqreset is for resetting ZQ to the default output impedance; Tzqcl is for long calibration(s); and Tzqcs is
for short calibration(s).
The initialization ZQ calibration (ZQINIT) must be performed for LPDDR2-S4. ZQINIT provides an output impedance
accuracy of +/-15 percent. After initialization, the ZQ calibration long (ZQCL) can be used to recalibrate the system to an
output impedance accuracy of +/-15 percent. A ZQ calibration short (ZQCS) can be used periodically to compensate for
temperature and voltage drift in the system.
The ZQ reset command (ZQRESET) resets the output impedance calibration to a default accuracy of +/-30% across
process, voltage, and temperature. This command is used to ensure output impedance accuracy to +/-30% when ZQCS
and ZQCL commands are not used.
One ZQCS command can effectively correct at least 1.5% (ZQ correction) of output impedance errors within Tzqcs for
all speed bins, assuming the maximum sensitivities specified are met. The appropriate interval between ZQCS commands can be determined from using these tables and system-specific parameters.
LPDDR2 devices are subject to temperature drift rate (Tdriftrate) and voltage drift rate (Vdriftrate) in various applications.
To accommodate drift rates and calculate the necessary interval between ZQCS commands, apply the following formula:
ZQcorrection
---------------------------------------------------(Tsens x Tdriftrate) + (Vsens x Vdriftrate)
where Tsens = max(dRONdT) and Vsens = max(dRONdV), define the LPDDR2 temperature and voltage sensitivities.
For example, if Tsens = 0.75% / C, Vsens = 0.20% / Mv, Tdriftrate = 1 C / sec and Vdriftrate = 15 Mv / sec, then the interval between ZQCS commands is calculated as:
1.5
----------------------------- = 0.4s
(0.75 x 1) + (0.20 x 15)
For LPDDR2-S4 devices, a ZQ Calibration command may only be issued when the device is in Idle state with all banks
precharged. No other activities can be performed on the LPDDR2 data bus during the calibration period (Tzqinit, Tzqcl,
Tzqcs). The quiet time on the LPDDR2 data bus helps to accurately calibrate RON. There is no required quiet time after
the ZQ Reset command. If multiple devices share a single ZQ Resistor, only one device may be calibrating at any given
time. After calibration is achieved, the LPDDR2 device shall disable the ZQ ball’s current consumption path to reduce
power.
In systems that share the ZQ resistor between devices, the controller must not allow overlap of Tzqinit, Tzqcs, or Tzqcl
between the devices. ZQ Reset overlap is allowed. If the ZQ resistor is absent from the system, ZQ shall be connected
permanently to VDDCA. In this case, the LPDDR2 shall ignore ZQ calibration commands and the device will use the
default calibration settings.
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ZQ Calibration Initialization timing example
Notes:
1. Only the NOP command is supported during ZQ calibration.
2. CKE must be registered HIGH continuously during the calibration period.
3. All devices connected to the DQ bus should be High-Z during the calibration process.
ZQ External Resistor Value, Tolerance and Capacitive Loading
To use the ZQ Calibration function, a 240 Ohm +/- 1% tolerance external resistor must be connected between the ZQ
pin and ground. A single resistor can be used for each LPDDR2 device or one resistor can be shared between multiple
LPDDR2 devices if the ZQ calibration timings for each LPDDR2 device do not overlap. The total capacitive loading on
the ZQ pin must be limited.
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Power Down
Power-down is entered synchronously when CKE is registered LOW and CS is HIGH at the rising edge of clock. CKE
must be registered HIGH in the previous clock cycle. A NOP command must be driven in the clock cycle following the
power-down command. CKE must not go LOW while MRR, MRW, READ, or WRITE operations are in progress. CKE
can go LOW while any other operations such as row activation, PRECHARGE, auto precharge, or REFRESH are in
progress, but the power-down IDD specification will not be applied until such operations are complete. Power-down
entry and exit are shown in below timing diagram.
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
must be held LOW; all other input signals are “Don’t Care.” CKE LOW must be maintained until Tcke is satisfied.
VREFCA must be maintained at a valid level during power-down.
VDDQ can be turned off during power-down. If VDDQ is turned off, VREFDQ must also be turned off. Prior to exiting
power-down, both VDDQ and VREFDQ must be within their respective minimum/maximum operating ranges.
No refresh operations are performed in power-down mode. The maximum duration in power-down mode is only limited
by the refresh requirements outlined in section “REFRESH Command”.
The power-down state is excited when CKE is registered HIGH. The controller must drive CS HIGH in conjunction with
CKE HIGH when exiting the power-down state. CKE HIGH must be maintained until Tcke is satisfied. A valid, executable
command can be applied with power-down exit latency Txp after CKE goes HIGH.
Basic Power-Down entry and exit timing
Notes: Input clock frequency can be changed or the input clock stopped during power-down, provided that the clock frequency is between the minimum and maximum specified frequencies for the speed grade in use, and that prior to
power-down exit, a minimum of 2 stable clocks complete.
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CKE intensive environment
REF to REF timing in CKE intensive environment
Notes:
1. The pattern shown above can repeat over a long period of time. With this pattern, LPDDR2 SDRAM guarantees all
AC and DC timing & voltage specifications with temperature and voltage drift ensured.
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Read to Power-Down entry
Notes:
1. CKE must be held HIGH until the end of the burst operation.
2. CKE may be registered LOW RL + RU(tDQSCK(MAX)/tCK) + BL/2 + 1 clock cycles after the clock on which the Read
command is registered.
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Read with Auto-precharge to Power-Down entry
Notes:
1. CKE must be held HIGH until the end of the burst operation.
2. CKE can be registered LOW at RL + RU(Tdqsck/Tck)+ BL/2 + 1 clock cycles after the clock on which the READ command is registered.
3. BL/2 with Trtp = 7.5ns and Tras (MIN) is satisfied.
4. Start internal PRECHARGE.
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Write to Power-Down entry
Notes:
5. CKE can be registered LOW at WL + 1 + BL/2 + RU(Twr/Tck) clock cycles after the clock on which the WRITE command is registered.
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Write with Auto-precharge to Power-Down entry
N
Notes:
1. CKE may be registered LOW WL + 1 + BL/2 + RU(tWR/tCK) +1 clock cycles after the Write command is registered.
2. Start internal PRECHARGE.
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Refresh command to Power-Down entry
Notes:
1.
t
CKE may go LOW IHCKE after the clock on which the Refresh command is registered.
Activate command to Power-Down entry
Notes:
1.
CKE may go LOW tIHCKE after the clock on which the Activate command is registered.
Precharge command to Power-Down entry
Notes:
1.
CKE may go LOW tIHCKE after the clock on which the Precharge command is registered.
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Mode Register Read to Power-Down entry
Notes:
1.
CKE may be registered LOW RL + RU(tDQSCK/tCK)+ BL/2 + 1 clock cycles after the clock on which the Mode Register Read
command is registered.
Mode Register Write to Power-Down entry
Notes:
6.
CKE may be registered LOW tMRW after the clock on which the Mode Register Write command is registered.
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Deep Power Down
Deep Power-Down is entered when CKE is registered LOW with CS LOW, CA0 HIGH, CA1 HIGH, and CA2 LOW at the
rising edge of clock. A NOP command must be driven in the clock cycle following the power-down command. CKE is not
allowed to go LOW while mode register, read, or write operations are in progress. All banks must be in idle state with no
activity on the data bus prior to entering the Deep Power Down mode. During Deep Power-Down, CKE must be held
LOW.
In Deep Power-Down mode, all input buffers except CKE, all output buffers, and the power supply to internal circuitry
may be disabled within the SDRAM. All power supplies must be within specified limits prior to exiting Deep Power-Down.
VrefDQ and VrefCA may be at any level within minimum and maximum levels. However prior to exiting Deep PowerDown, Vref must be within specified limits.
The contents of the SDRAM may be lost upon entry into Deep Power-Down mode.
The Deep Power-Down state is exited when CKE is registered HIGH, while meeting Tiscke with a stable clock input. The
SDRAM must be fully re-initialized as described in the Power up initialization Sequence. The SDRAM is ready for normal
operation after the initialization sequence.
Deep Power-Down entry and exit timing diagram
Notes:
1. Initialization sequence may start at any time after Tx + 1.
2. Tinit3 and Tx + 1 and refer to timings in the initialization sequence.
3. The clock is stable and within specified limits for a minimum of 2 clock cycles prior to deep power down exit and the
clock frequency is between the minimum and maximum frequency for the particular speed grade.
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Input clock stop and frequency change
LPDDR2 devices support input clock frequency change during CKE LOW under the following conditions:
- Tck(abs)min is met for each clock cycle
- Refresh requirement apply during clock frequency change
- During clock frequency change, only REFab or REFpb commands may be executing
- Any ACTIVATE or PRECHARGE commands have completed prior to changing the frequency
- Related timing conditions,Trcd and Trp, have been met prior to changing the frequency
- The initial clock frequency must be maintained for a minimum of 2 clock cycles after CKE goes LOW
- The clock satisfies Tch(abs) and Tcl(abs) for a minimum of two clock cycles prior to CKE going HIGH.
After the input clock frequency is changed and CKE is held HIGH, additional MRW commands may be required to set
the WR, RL, etc. These settings may need to be adjusted to meet minimum timing requirements at the target clock frequency.
LPDDR2 devices support clock stop during CKE LOW under the following conditions:
- CK is held LOW and CK is held HIGH during clock stop
- Refresh requirements are met
- Only REFab or REFpb commands can be in process
- Any ACTIVATE or PRECHARGE commands have completed prior to changing the frequency
- Related timing conditions,Trcd and Trp, have been met prior to changing the frequency
- The initial clock frequency must be maintained for a minimum of 2 clock cycles after CKE goes LOW
- The clock satisfies Tch(abs) and Tcl(abs) for a minimum of two clock cycles prior to CKE going HIGH
LPDDR2 devices support input clock frequency change during CKE HIGH under the following conditions:
- Tck(abs)min is met for each clock cycle
- Refresh requirement apply during clock frequency change
- Any Activate, Read, Write, Precharge, Mode Register Write or Mode Register Read commands must have executed to
completion including any associated data bursts prior to changing the frequency
- The related timing conditions (Trcd, Twr, Twra, Trp,Tmrw,Tmrr etc) have been met prior to changing the frequency
- CS shall be held HIGH during clock frequency change
- During clock frequency change, only REFab or REFpb commands may be executing
- The LPDDR2 device is ready for normal operation after the clock satisfies Tch(abs) and Tcl(abs) for a minimum of
2Tck+Txp
After the input clock frequency is changed and CKE is held HIGH, additional MRW commands may be required to set
the WR, RL, etc. These settings may need to be adjusted to meet minimum timing requirements at the target clock frequency.
LPDDR2 devices support clock stop during CKE HIGH under the following conditions:
- CK is held LOW and CK is held HIGH during clock stop
- CS shall be held HIGH during clock stop
- Refresh requirements are met
- Only REFab or REFpb commands can be in process
- Any Activate, Read, Write, Precharge, Mode Register Write or Mode Register Read commands must have executed to
completion including any associated data bursts prior to stopping the clock
- The related timing conditions (Trcd, Twr, Twra, Trp,Tmrw,Tmrr etc) have been met prior to stopping the clock
- The LPDDR2 device is ready for normal operation after the clock is restarted and satisfies Tch(abs) and Tcl(abs) for a
minimum of 2Tck+Txp
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No Operation Command
The purpose of the No Operation command (NOP) is to prevent the LPDDR2 device from registering any unwanted
command between operations. Only when the CKE level is constant for clock cycle N-1 and clock cycle N, a NOP command may be issued at clock cycle N. A NOP command has two possible encodings:
1. CS HIGH at the clock rising edge N.
2. CS LOW and CA0, CA1, CA2 HIGH at the clock rising edge N.
The No Operation command will not terminate a previous operation that is still executing, such as a burst read or write
cycle.
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Absolute Maximum DC Ratings
Symbol
Parameter
Min
Max
Units
Note
VDD1
Voltage on VDD1 pin relative to Vss
-0.4
2.3
V
2
VDD2
Voltage on VDD2 pin relative to Vss
-0.4
1.6
V
2
VDDCA
Voltage on VDDCA pin relative to Vss
-0.4
1.6
V
2,4
VDDQ
Voltage on VDDQ pin relative to Vss
-0.4
1.6
V
2,3
Vin, Vout
Voltage on any pin relative to Vss
-0.4
1.6
V
Tstg
Storage Temperature (plastic)
-55
125
°C
5
Notes :
1. Stresses greater than those listed under “Absolute Maximum Ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions
for extended periods may affect reliability.
2. See “Power-Ramp” for relationships between power supplies.
3. VREFDQ =< 0.6 x VDDQ; however, VREFDQ may be => VDDQ provided that VREFDQ =< 300mV.
4. VREFCA =< 0.6 x VDDCA; however, VREFCA may be => VDDCA provided that VREFCA =< 300mV.
5. Storage Temperature is the case surface temperature on the center/top side of the LPDDR2 device. For the
measurement conditions, please refer to JESD51-2 standard.
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AC/DC Operating Conditions
Operating Temperature Condition
Symbol
Parameter
Rating
Units
TOPER
Operating case temperature(Commercial)
-25 to +85
°C
TOPER
Operating case temperature(Industrial)
-40 to +85
°C
Notes
Notes :
1. Operating Temperature is the case surface temperature on the center/top side of the LPDDR2 device. For the measurement conditions, please refer to JESD51-2 standard.
2. Either the device case temperature rating or the temperature sensor may be used to set an appropriate refresh rate,
determine the need for AC timing de-rating and/or monitor the operating temperature. When using the temperature sensor, the actual device case temperature may be higher than the TOPER rating that applies for the Standard or Extended
Temperature Ranges. For example, TCASE may be above 85°C when the temperature sensor indicates a temperature
of less than 85°C.
Recommended DC Operating Conditions
Symbol
Parameter
VDD1
Rating
Min.
Typ.
Max.
Units
Core supply voltage 1
1.70
1.80
1.95
V
VDD2
Core supply voltage 2
1.14
1.20
1.30
V
VDDCA
Input supply voltage
1.14
1.20
1.30
V
VDDQ
I/O supply voltage
1.14
1.20
1.30
V
Notes
Input Leakage Current
Symbol
IL
IVREF
parameter
Min
Max
Units
Notes
Input Leakage current
For CA, CKE, CS, CK, CK
Any input 0V =< VIN =< VDDCA
(All other pins not under test = 0V)
-2
2
uA
1
VREF supply leakage current
VREFDQ = VDDQ/2 or VREFCA = VDDCA/2
(All other pins not under test = 0V)
-1
1
uA
2
Notes :
1. The minimum limit requirement is for testing purposes. The leakage current on VREFCA and VREFDQ pins should be
minimal.
2. Although DM is for input only, the DM leakage shall match the DQ and DQS/DQS output leakage specification.
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AC and DC Input Measurement Levels
Single-Ended AC and DC Input Levels for CA and CS Signals
Symbol
Parameter
LPDDR2 1600-466
LPDDR2 400-200
Min
Max
Min
-
VREFCA +
0.3V
Unit
Notes
-
V
1,2
-
VREFCA +
0.3V
V
1,2
VREFCA +
0.2V
VDDCA
V
1
VREFCA +
0.2V
V
1
V
3,4
VIHCA(AC)
AC input logic high
VREFCA +
0.22V
VILCA(AC)
AC input logic Low
-
VIHCA(DC)
DC input logic high
VREFCA +
0.13V
VILCA(DC)
DC input logic Low
VSSCA
VREFCA 0.13V
VSSCA
0.49 x
VDDCA
0.51 x
VDDCA
0.49 x
VDDCA
VREFCA(DC) Reference Voltage for CA and
CS inputs
VREFCA 0.22V
VDDCA
Max
0.51 x
VDDCA
Notes :
1. For CA and CS input only pins. VREF = VREFCA(DC).
2. See Overshoot and Undershoot Specifications section.
3. The ac peak noise on VREFCA may not allow VREFCA to deviate from VREFCA(DC) by more than +/-1% VDDCA
(for reference: approx. +/- 12 mV).
4. For reference : approx. VDD/2 ±12 mV.
Single-Ended AC and DC Input Levels for CKE
Symbol
Parameter
Min.
Max.
Units
Notes
VIHCKE
CKE input high level
0.8 x VDDCA
-
V
1
VILCKE
CKE input low level
-
0.2 x VDDCA
V
1
Notes :
1. See Overshoot and Undershoot Specifications section.
Single-Ended AC and DC Input Levels for DQ and DM Signals
Symbol
Parameter
LPDDR2 1600-466
LPDDR2 400-200
Min
Max
Min
-
VREFCA +
0.3V
VIHDQ(AC)
AC input logic high
VREFCA +
0.22V
VILDQ(AC)
AC input logic Low
-
VIHDQ(DC)
DC input logic high
VREFCA +
0.13V
VILDQ(DC)
DC input logic Low
VSSQ
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VDDQ
VREFCA 0.13V
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Unit
Notes
-
V
1,2
-
VREFCA +
0.3V
V
1,2
VREFCA +
0.2V
VDDQ
V
1
VSSQ
VREFCA +
0.2V
V
1
Max
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VREFDQ(DC) Reference Voltage for DQ and
DM inputs
0.49 x
VDDQ
0.51 x
VDDQ
0.49 x
VDDQ
0.51 x
VDDQ
V
3,4
Notes :
1. For DQ input only pins. VREF = VREFDQ(DC).
2. See Overshoot and Undershoot Specifications section.
3. The ac peak noise on VREFDQ may not allow VREFDQ to deviate from VREFDQ(DC) by more than +/-1% VDDDQ
(for reference: approx. +/- 12 mV).
4. For reference : approx. VDD/2 ±12 mV.
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VREF Tolerances
The DC tolerance limits and AC noise limits for the reference voltages VREFCA and VREFDQ are illustrated bellow.
This figure shows a valid reference voltage VREF(t) as a function of time. VDD is used in place of VDDCA for VREFCA,
and VDDQ for VREFDQ. VREF(DC) is the linear average of VREF(t) over a very long period of time (e.g., 1 second) and
is specified as a fraction of the linear average of VDDQ or VDDCA, also over a very long period of time (e.g., 1 second).
This average must meet the MIN/MAX requirements. Additionally, VREF(t) can temporarily deviate from VREF(DC) by
no more than +/-1% VDD. VREF(t) cannot track noise on VDDQ or VDDCA if doing so would force VREF outside these
specifications.
voltage
VDD
VSS
time
VREF(DC) tolerance and VREF AC-Noise limits
The voltage levels for setup and hold time measurements VIH(AC), VIH(DC), VIL(AC), and VIL(DC) are dependent on
VREF. VREF DC variations affect the absolute voltage a signal must reach to achieve a valid HIGH or LOW, as well as
the time from which setup and hold times are measured. When VREF is outside the specified levels, devices will function correctly with appropriate timing deratings as long as:
VREF is maintained between 0.44 x VDDQ (or VDDCA) and 0.56 x VDDQ (or VDDCA), and the controller achieves the
required single-ended AC and DC input levels from instantaneous VREF.
System timing and voltage budgets must account for VREF deviations outside this range.
This also clarifies that the LPDDR2 setup/hold specification and derating values need to include time and voltage associated with VREF AC-noise. Timing and voltage effects due to AC-noise on VREF up to the specified limit (+/- 1% of
VDD) are included in LPDDR2 timings and their associated deratings.
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Input Signals
LPDDR2-466 to LPDDR2-1066 Input Signal
VIL and VIH Levels With Ringback
1.550V
VDD + 0.35V
1.200V
VDD
0.820V
VIH(AC)
0.730V
VIH(DC)
Minimum VIL and VIH Levels
0.820V
0.730V
VIH(AC)
VIH(DC)
0.624V
0.612V
0.600V
0.588V
0.576V
0.470V
0.380V
0.624V
0.612V
0.600V
0.588V
0.576V
VIL(DC)
VIL(AC)
VREF + AC noise
VREF + DC error
VREF - DC error
VREF - AC noise
0.470V
VIL(DC)
0.380V
VIL(AC)
0.000V
VSS
-0.350V
VSS - 0.35V
Notes:
1. Numbers reflect typical values.
2. For CA[9:0], CK, CK, CS, and CKE, VDD stands for VDDCA. For DQ, DM, DQS, and DQS, VDD stands for VDDQ.
3. For CA[9:0], CK, CK, CS, and CKE, VSS stands for VSSCA. For DQ, DM, DQS, and DQS, VSS stands for VSSQ.
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LPDDR2-200 to LPDDR2-400 Input Signal
VIL and VIH Levels With Ringback
1.550V
VDD + 0.35V
1.200V
VDD
0.900V
VIH(AC)
0.800V
VIH(DC)
Minimum VIL and VIH Levels
0.900V
0.800V
VIH(AC)
VIH(DC)
0.624V
0.612V
0.600V
0.588V
0.576V
0.624V
0.612V
0.600V
0.588V
0.576V
0.400V
0.300V
VIL(DC)
VIL(AC)
VREF + AC noise
VREF + DC error
VREF - DC error
VREF - AC noise
0.400V
VIL(DC)
0.300V
VIL(AC)
0.000V
VSS
-0.350V
VSS - 0.35V
Notes:
1. Numbers reflect typical values.
2. For CA[9:0], CK, CK, CS, and CKE, VDD stands for VDDCA. For DQ, DM, DQS, and DQS, VDD stands for VDDQ.
3. For CA[9:0], CK, CK, CS, and CKE, VSS stands for VSSCA. For DQ, DM, DQS, and DQS, VSS stands for VSSQ.
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AC and DC Logic Input Levels for Differential Signals
Differential signals definition
tDVAC
Differential Input Voltage (i.e. DQS-DQS, CK-CK)
VIH.DIFF.AC.MIN
VIH.DIFF.MIN
0.0
half cycle
VIL.DIFF.MAX
VIL.DIFF.AC.MAX
tDVAC
time
Definition of differential ac-swing and "time above ac level" tDVAC
Differential swing requirement for clock (CK - CK) and strobe (DQS - DQS)
Differential AC and DC Input Levels
LPDDR2 1600-466
LPDDR2 400-200
Min
Max
Min
VIHDIFF(AC) Differential input high
2 x (VIH(ac) VREF)
Note 3
2 x (VIH(ac) VREF)
VILDIFF(AC) Differential input low
Note 3
VIHDIFF(DC) Differential input high
2 x (VIH(dc) VREF)
VILDIFF(DC) Differential input low
Note 3
Symbol
Parameter
2 x (VIL(ac) Vref)
Note 3
2 x (VIL(dc) Vref)
Unit
Notes
Note 3
V
2
Note 3
2 x (VIL(ac) Vref)
V
2
2 x (VIH(dc) VREF)
Note 3
V
1
Note 3
2 x (VIL(dc) Vref)
V
1
Max
Notes :
1. Used to define a differential signal slew-rate. For CK - CK use VIH/VIL(DC) of address/command and VREFCA; for
strobes (DQS, DQS) use VIH/VIL(DC) of DQs and VREFDQ; if a reduced dc-high or dc-low level is used for a signal
group, then the reduced level applies also here.
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2. For CK - CK use VIH/VIL(AC) of CA and VREFCA; for DQS - DQS, use VIH/VIL(AC) of DQs and VREFDQ; if a
reduced ac-high or ac-low level is used for a signal group, then the reduced level applies also here.
3. These values are not defined, however the single-ended signals CK, CK, DQS, and DQS must be within the respective limits (VIH(DC)max, VIL(DC)min) for single-ended signals and must comply with the specified limitations for overshoot and undershoot.
Allowed time before ringback (tDVAC) for CK - CK and DQS - DQS
tDVAC [ps] @ |VIH/
Ldiff(AC)| = 440mV
tDVAC [ps] @ |VIH/
Ldiff(AC)| = 600mV
Min.
Min.
> 4.0
175
75
4.0
170
57
3.0
167
50
2.0
163
38
1.8
162
34
1.6
161
29
1.4
159
22
1.2
155
13
1.0
150
0
< 1.0
150
0
Slew Rate [V/ns]
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Single-ended requirements for differential signals
Each individual component of a differential signal (CK, DQS, CK, DQS) has also to comply with certain requirements for
single-ended signals.
CK and CK shall meet VSEH(AC) min / VSEL(AC) max in every half-cycle.
DQS, DQS shall meet VSEH(AC) min / VSEL(AC) max in every half-cycle proceeding and following a valid transition.
Note that the applicable AC-levels for CA and DQ’s are different per speed-bin.
VDD or VDDQ
VSEH min
VSEH
VDD/2 or VDDQ/2
CK or DQS
VSEL max
VSEL
VSS or VSSQ
time
Single-ended requirement for differential signals
Note that while CA and DQ signal requirements are with respect to VREF, the single-ended components of differential
signals have a requirement with respect to VDDQ/2 for DQS, DQS and VDDCA/2 for CK, CK; this is nominally the same.
The transition of single-ended signals through the AC-levels is used to measure setup time. For single-ended components of differential signals the requirement to reach VSEL(AC) max, VSEH(AC) min has no bearing on timing, but adds
a restriction on the common mode characteristics of these signals.
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AS4C128M32MD2-18BIN
Single-ended levels for CK, DQS, CK, DQS
Symbol
Parameter
LPDDR21600-466
Min
VSEH(AC)
VSEL(AC)
Single-ended high-level for
strobes
LPDDR400-200
Max
(VDDQ/2)
+ 0.22
Single-ended high-level for (VDDCA/2)
CK, CK
+ 0.22
Min
Max
Unit
Notes
NOTE 3
(VDDQ/2)
+ 0.3
NOTE 3
V
2
NOTE 3
(VDDCA/2)
+ 0.3
NOTE 3
V
2
Single-ended low-level for
strobes
NOTE 3
(VDDQ/2)
- 0.22
NOTE 3
(VDDQ/2)
- 0.22
V
1
Single-ended low-level for
CK, CK
NOTE 3
(VDDCA/2)
- 0.22
NOTE 3
(VDDCA/2)
- 0.22
V
1
Notes :
1. For CK, CK use VIH/VIL(AC) of CA; for strobes (DQS, DQS) use VIH/VIL(AC) of DQs.
2. VIH(AC)/VIL(AC) for DQs is based on VREFDQ; VSEH(AC)/VSEL(AC) for CA is based on VREFCA; if a reduced
AC-high or AC-low level is used for a signal group, then the reduced level applies also here.
3. These values are not defined, however the single-ended components of differential signals CK, CK, DQS, DQS need
to be within the respective limits (VIH(DC) max, VIL(DC) min) for single-ended signals as well as the limitations for
overshoot and undershoot. Refer to "Overshoot and Undershoot specifications”.
Differential Input Cross Point Voltage
To guarantee tight setup and hold times as well as output skew parameters with respect to clock and strobe, each cross
point voltage of differential input signals (CK, CK and DQS, DQS) must meet the requirements in below table. The differential input cross point voltage VIX is measured from the actual cross point of true and complement signal to the mid
level between of VDD and VSS.
VDD
CK, DQS
VIX
VDD/2
VIX
VIX
CK, DQS
VSS
VIX Definition
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Cross point voltage for differential input signals ( CK, DQS )
Symbol
Parameter
Min.
Max.
Units
Notes
VIXCA
Differential Input Cross Point Voltage relative to VDDCA/2 for CK, CK
-120
120
mV
1,2
VIXDQ
Differential Input Cross Point Voltage relative to VDDDQ/2 for DQS, DQS
-120
120
mV
1,2
Notes :
1. The typical value of VIX(AC) is expected to be about 0.5 x VDD of the transmitting device, and VIX(AC) is expected to
track variations in VDD. VIX(AC) indicates the voltage at which differential input sig-nals must cross.
2. For CK and CK, VREF = VREFCA(DC). For DQS and DQS, VREF = VREFDQ(DC).
Differential input slew rate definition
Measured
Description
Defined by
From
To
Differential input slew rate for rising edge ( CK-CK and DQS-DQS )
VILdiff (max)
VIHdiff (min)
VIHdiff (min) - VILdiff (max)
Delta TRdiff
Differential input slew rate for falling edge ( CK-CK and DQS-DQS )
VIHdiff (min)
VILdiff (max)
VIHdiff (min) - VILdiff (max)
Delta TFdiff
Notes : The differential signal (i.e. CK - CK and DQS - DQS) must be linear between these thresholds.
VIHdiffmin
0
VILdiffmax
delta TFdiff
delta TRdiff
Differential Input Slew Rate definition for DQS, DQS, and CK, CK
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AS4C128M32MD2-18BIN
AC and DC Output Measurement Levels
Single-ended AC & DC Output Levels
Parameter
LPDDR2-1600 to
LPDDR2-200
Units
Notes
VOH(DC)
DC output high measurement level (for IV curve linearity)
0.9 x VDDQ
V
1
VOL(DC)
DC output mid measurement level (for IV curve linearity)
0.1 x VDDQ
V
2
VOH(AC)
AC output high measurement level (for output SR)
VREFDQ+0.12
V
VOL(AC)
AC output low measurement level (for output SR)
VREFDQ-0.12
V
Output Leakage current (DQ, DM, DQS, DQS)
(DQ, DQS, DQS are disabled; 0V =< VOUT =< VDDQ)
-5 (min)
uA
5 (max)
uA
Delta RON between pull-up and pull-down for DQ/DM
-15 (min)
%
15 (max)
%
Parameter
LPDDR2-1600 to
LPDDR2-200
Units
VOHdiff(AC)
AC differential output high measurement level (for output SR)
+0.2 x VDDQ
V
VOLdiff(AC)
AC differential output low measurement level (for output SR)
-0.2 x VDDQ
V
Symbol
IOZ
MMPUPD
Notes :
1. IOH = -0.1mA.
2. IOL = -0.1mA.
Differential AC & DC Output Levels
Symbol
Notes
Notes :
1. IOH = -0.1mA.
2. IOL = -0.1mA.
Single-ended Output Slew Rate
With the reference load for timing measurements, output slew rate for falling and rising edges is defined and measured
between VOL(AC) and VOH(AC) for single ended signals.
Description
Measured
Defined by
From
To
Single ended output slew rate for rising edge
VOL(AC)
VOH(AC)
VOH(AC)-VOL(AC)
Delta TRse
Single ended output slew rate for falling edge
VOH(AC)
VOL(AC)
VOH(AC)-VOL(AC)
Delta TRse
Notes : Output slew rate is verified by design and characterization, and may not be subject to production test.
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Single-ended Output Slew Rate definition
LPDDR2-1600 to LPDDR2-200
Parameter
Symbol
Single ended output slew rate (RON = 40Ω +/- 30%)
SRQse
Single ended output slew rate (RON = 60Ω +/- 30%)
SRQse
Output slew-rate matching Ratio (Pull-up to Pull-down)
Units
Min
Max
1.5
3.5
V/ns
1
2.5
V/ns
0.7
1.4
Description : SR : Slew Rate
Q : Query Output (like in DQ, which stands for Data-in, Query-Output)
se : Single-ended Signals
Notes :
1. Measured with output reference load.
2. The ratio of pull-up 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.
3. The output slew rate for falling and rising edges is defined and measured between VOL(AC) and VOH(AC).
4. Slew rates are measured under normal SSO conditions, with 1/2 of DQ signals per data byte driving logic-high and 1/
2 of DQ signals per data byte driving logic-low.
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Differential Output Slew Rate
With the reference load for timing measurements, output slew rate for falling and rising edges is defined and measured
between VOLdiff(AC) and VOH-diff(AC) for differential signals.
Measured
Description
Defined by
From
To
Differential output slew rate for rising edge
VOLdiff(AC)
VOHdiff(AC)
VOHdiff(AC)-VOLdiff(AC)
Delta TRdiff
Differential output slew rate for falling edge
VOHdiff(AC)
VOLdiff(AC)
VOHdiff(AC)-VOLdiff(AC))
Delta TFdiff
Notes : Output slew rate is verified by design and characterization, and may not be subject to production test.
Differential Output Slew Rate definition
LPDDR2-1600 to LPDDR2-200
Parameter
Symbol
Units
Min
Max
Single ended output slew rate (RON = 40Ω +/- 30%)
SRQdiff
3.0
7.0
V/ns
Single ended output slew rate (RON = 60Ω +/- 30%)
SRQdiff
2.0
5.0
V/ns
Description : SR : Slew Rate
Q : Query Output (like in DQ, which stands for Data-in, Query-Output)
diff : Differential Signals
Notes :
1. Measured with output reference load.
2. he output slew rate for falling and rising edges is defined and measured between VOL(AC) and VOH(AC).
3. Slew rates are measured under normal SSO conditions, with 1/2 of DQ signals per data byte driving logic-high and 1/
2 of DQ signals per data byte driving logic-low.
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Overshoot and Undershoot Specification
AC Overshoot/Undershoot specifications
Parameter
Specification
1066 933
800
667
533
466
400
333
266
200
Unit
Maximum peak amplitude allowed for overshoot area
0.35
V
Maximum peak amplitude allowed for undershoot area
0.35
V
Maximum overshoot area above VDD
0.15 0.17 0.20 0.24 0.30 0.35 0.40 0.48 0.60 0.80
V-ns
Maximum undershoot area below VSS
0.15 0.17 0.20 0.24 0.30 0.35 0.40 0.48 0.60 0.80
V-ns
Address and Control Overshoot and Undershoot Definition
Notes:
1. For CA0-9, CK, CK, CS, and CKE, VDD stands for VDDCA. For DQ, DM, DQS, and DQS, VDD stands for VDDQ.
2. For CA0-9, CK, CK, CS, and CKE, VSS stands for VSSCA. For DQ, DM, DQS, and DQS, VSS stands for VSSQ.
3. Maximum peak amplitude values are referenced from actual VDD and VSS values.
4. Maximum area values are referenced from maximum operating VDD and VSS values.
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Input/Output Capacitance
LPDDR2 1066-466
LPDDR2 400-200
Min
Max
Min
Max
CCK
1
2
1
CDCK
0
0.2
Input capacitance
(All other input-only pins)
CI
1
Input capacitance delta
(All other input-only pins)
CDI
Input/output capacitance
(DQ, DQS, DQS, DM)
Parameter
Units
NOTE
2
pF
1,2
0
0.25
pF
1,2,3
2
1
2
pF
1,2,4
-0.4
0.4
-0.5
0.5
pF
1,2,5
CIO
1.25
2.5
1.25
2.5
pF
1,2,6,7
Input/output capacitance delta
(DQS and DQS)
CDDQS
0
0.25
0
0.3
pF
1,2,7,8
Input/output capacitance delta
(DQ, DM)
CDIO
-0.5
0.5
-0.6
0.6
pF
1,2,7,9
Input/output capacitance: ZQ
CZQ
0
2.5
0
2.5
pF
1,2
Input capacitance
(CK and CK)
Input capacitance delta
(CK and CK)
Symbol
Notes :
1. This parameter applies to die device only (does not include package capacitance).
2. 2This parameter is not subject to production test. It is verified by design and characterization. The capacitance is
measured according to JEP147 (Procedure for measuring input capacitance using a vector network analyzer) with
VDD1, VDD2, VDDQ, VSS, VSSCA, VSSQ applied and all other pins floating.
3. Absolute value of CCK-CCK
4. CI applies to CS, CKE, CA0-CA9.
5. CDI = CI - 0.5 * (CCK + CCK)
6. DM loading matches DQ and DQS.
7. MR3 I/O configuration DS OP3-OP0 = 0001B (34.3 Ohm typical).
8. Absolute value of CDQS and CDQS.
9. CDIO = CIO - 0.5 * (CDQS + CDQS) in byte-lane.
10. Maximum external load capacitance on ZQ pin, including packaging, board, pin, resistor, and other LPDDR2
devices: 5 pF.
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AS4C128M32MD2-18BIN
IDD Specification
(VDD2, VDDQ,VDDCA = 1.14~1.30V, VDD1 = 1.70~1.95V)
Conditions
Operating One Bank Active-Precharge Current:
tCK = tCK(avg)min; tRC = tRCmin;
CKE is HIGH;
CS is HIGH between valid commands;
CA bus inputs are SWITCHING;
Data bus inputs are STABLE
Idle power-down standby current:
tCK = tCK(avg)min;
CKE is LOW;
CS is HIGH;
All banks/RBs idle;
CA bus inputs are SWITCHING;
Data bus inputs are STABLE
Idle power-down standby current with clock stop:
CK =LOW, CK =HIGH;
CKE is LOW;
CS is HIGH;
All banks/RBs idle;
CA bus inputs are STABLE;
Data bus inputs are STABLE
Idle non power-down standby current:
tCK = tCK(avg)min;
CKE is HIGH;
CS is HIGH;
All banks/RBs idle;
CA bus inputs are SWITCHING;
Data bus inputs are STABLE
Idle non power-down standby current with clock stop:
CK_t =LOW,
CK_c =HIGH;
CKE is HIGH;
CS is HIGH;
All banks/RBs idle;
CA bus inputs are STABLE;
Data bus inputs are STABLE
Active power-down standby current:
tCK = tCK(avg)min;
CKE is LOW;
CS is HIGH;
One bank/RB active;
CA bus inputs are SWITCHING;
Data bus inputs are STABLE
Confidential
Symbol
Power Supply
1066
Unit
IDD01
IDD02
IDD0IN
VDD1
VDD2
VDDCA,VDDQ
15
70
10
mA
IDD2P1
IDD2P2
IDD2PIN
VDD1
VDD2
VDDCA,VDDQ
600
800
120
uA
IDD2PS1
IDD2PS2
IDD2PSIN
VDD1
VDD2
VDDCA,VDDQ
600
800
120
uA
IDD2N1
IDD2N2
IDD2NIN
VDD1
VDD2
VDDCA,VDDQ
2
20
10
mA
IDD2NS1
IDD2NS2
IDD2NSIN
VDD1
VDD2
VDDCA,VDDQ
1.7
10
6
mA
IDD3P1
IDD3P2
IDD3PIN
VDD1
VDD2
VDDCA,VDDQ
1000
7.5
150
uA
mA
uA
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Conditions
Symbol
Power Supply
1066
Unit
IDD3PS1
IDD3PS2
IDD3PSIN
VDD1
VDD2
VDDCA,VDDQ
1200
7.5
150
uA
mA
uA
IDD3N1
IDD3N2
IDD3NIN
VDD1
VDD2
VDDCA,VDDQ
2
25
10
mA
IDD3NS1
IDD3NS2
IDD3NSIN
VDD1
VDD2
VDDCA,VDDQ
2
20
6
mA
Operating burst read current:
tCK = tCK(avg)min;
CS is HIGH between valid commands;
One bank/RB active;
BL = 4; RL = RLmin;
CA bus inputs are SWITCHING;
50% data change each burst transfer
IDD4R1
IDD4R2
IDD4RIN
IDD4RQ
VDD1
VDD2
VDDCA
VDDQ
3
250
10
mA
Operating burst write current:
tCK = tCK(avg)min;
CS is HIGH between valid commands;
One bank/RB active;
BL = 4; WL = WLmin;
CA bus inputs are SWITCHING;
50% data change each burst transfer
IDD4W1
IDD4W2
IDD4WIN
VDD1
VDD2
VDDCA,VDDQ
3
250
35
mA
IDD51
IDD52
IDD5IN
VDD1
VDD2
VDDCA,VDDQ
20
150
10
mA
IDD5AB1
IDD5AB2
IDD5ABIN
VDD1
VDD2
VDDCA,VDDQ
5
25
10
mA
Active power-down standby current with clock stop:
CK=LOW, CK=HIGH;
CKE is LOW;
CS is HIGH;
One bank/RB active;
CA bus inputs are STABLE;
Data bus inputs are STABLE
Active non power-down standby current:
tCK = tCK(avg)min;
CKE is HIGH;
CS is HIGH;
One bank/RB active;
CA bus inputs are SWITCHING;
Data bus inputs are STABLE
Active non power-down standby current with clock stop:
CK=LOW, CK=HIGH;
CKE is HIGH;
CS is HIGH;
One bank/RB active;
CA bus inputs are STABLE;
Data bus inputs are STABLE
All Bank Refresh Burst current:
tCK = tCK(avg)min;
CKE is HIGH between valid commands;
tRC = tRFCabmin;
Burst refresh;
CA bus inputs are SWITCHING;
Data bus inputs are STABLE
All Bank Refresh Average current:
tCK = tCK(avg)min;
CKE is HIGH between valid commands;
tRC = tREFI;
CA bus inputs are SWITCHING;
Data bus inputs are STABLE
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AS4C128M32MD2-18BIN
Conditions
Symbol
Power Supply
1066
Unit
IDD5PB1
IDD5PB2
IDD5PBIN
VDD1
VDD2
VDDCA,VDDQ
5
25
10
mA
IDD61
IDD62
IDD6IN
VDD1
VDD2
VDDCA,VDDQ
1000
4000
120
uA
IDD6ET1
IDD6ET2
IDD6ETIN
VDD1
VDD2
VDDCA,VDDQ
TBD
TBD
TBD
mA
Per Bank Refresh Average current:
tCK = tCK(avg)min;
CKE is HIGH between valid commands;
tRC = tREFI/8;
CA bus inputs are SWITCHING;
Data bus inputs are STABLE
Self refresh current (Standard Temperature Range):
CK=LOW, CK=HIGH;
CKE is LOW;
CA bus inputs are STABLE;
Data bus inputs are STABLE;
Maximum 1x Self-Refresh Rate
Self refresh current (+85’C to +105’C):
CK=LOW, CK=HIGH;
CKE is LOW;
CA bus inputs are STABLE;
Data bus inputs are STABLE;
Notes :
1. Published IDD values are the maximum of the distribution of the arithmetic mean.
2. IDD current specifications are tested after the device is properly initialized.
3. The 1x self refresh rate is the rate at which the device is refreshed internally during self refresh, before going into the
extended temperature range.
4. Measured currents are the summation of VDDQ and VDDCA.
5. Guaranteed by design with output load of 5PF and RON = 40Ohm.
6. Per Bank Refresh only applicable for LPDDR2-S4 devices of 1Gb or higher densities
7. This is the general definition that applies to full-array SELF REFRESH).
8. IDD6ET is typical values
IDD6 Partial Array Self-Refresh Current
PASR
Supply
1066
Full Array
VDD1
VDD2
VDDCA,VDDQ
1000
4000
120
uA
1/2 Array
VDD1
VDD2
VDDCA,VDDQ
950
2300
120
uA
1/4 Array
VDD1
VDD2
VDDCA,VDDQ
900
1500
120
uA
1/8 Array
VDD1
VDD2
VDDCA,VDDQ
850
1060
120
uA
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AS4C128M32MD2-18BCN
AS4C128M32MD2-18BIN
REFRESH Requirements by Device Density
LPDDR2-S4 Refresh Requirement Parameters (per density)
Symbol
Parameter
4Gb(Single Die)
8Gb(Dual Dies)
Unit
Number of banks
8
tREFW
Refresh window: TCASE =< 85’C
32
ms
tREFW
Refresh window: 85’C < TCASE =< 105’C
8
ms
R
Required number of REFRESH commands (MIN)
8192
8192
tREFI
Average time between REFRESH commands (for
reference only) TCASE <= 85’C
3.9
3.9
us
0.4875
0.4875
us
tREFIpb
tRFCab
Refresh cycle time
130
130
ns
tRFCpb
Per-bank REFRESH cycle time
60
60
ns
tREFBW
Burst REFRESH window = 4 x 8 x tRFCab
4.16
4.16
us
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AS4C128M32MD2-18BIN
AC Characteristics
(VDD2, VDDQ,VDDCA = 1.14~1.30V, VDD1 = 1.70~1.95V)
Parameter
Symbol
min/max min tCK
Speed Grade
1066
800
~
533
400
min
1.875
2.5
Unit
Clock Timing
Max. Frequency
Average Clock Period
tCK(avg)
Average HIGH pulse width
tCH(avg)
Average LOW pulse width
tCL(avg)
Absolute Clock Period
ns
max
100
min
0.45
max
0.55
min
0.45
max
0.55
tCK(abs)
min
tCK(avg)min + tJIT(per),min
Absolute clock HIGH pulse width
(with allowed jitter)
tCH(abs),
allowed
min
0.43
max
0.57
Absolute clock LOW pulse width
(with allowed jitter)
tCL(abs),
allowed
min
0.43
max
0.57
Clock Period Jitter
(with allowed jitter)
tJIT(per),
allowed
Maximum Clock Jitter between two
consecutive clock cycles (with allowed jitter)
tJIT(cc),
allowed
Duty cycle Jitter
(with allowed jitter)
Cumulative error across 2 cycles
Cumulative error across 3 cycles
Cumulative error across 4 cycles
Cumulative error across 5 cycles
Cumulative error across 6 cycles
Cumulative error across 7 cycles
Confidential
tJIT(duty),
allowed
tERR(2per),
allowed
tERR(3per),
allowed
tERR(4per),
allowed
tERR(5per),
allowed
tERR(6per),
allowed
tERR(7per),
allowed
tCK(avg)
tCK(avg)
ps
tCK(avg)
tCK(avg)
min
-90
-100
max
90
100
max
180
200
min
min((tCH(abs),min - tCH(avg),min),
(tCL(abs),min - tCL(avg),min)) * tCK(avg)
max
max((tCH(abs),max - tCH(avg),max),
(tCL(abs),max - tCL(avg),max)) * tCK(avg)
min
-132
-147
max
132
147
min
-157
-175
max
157
175
min
-175
-194
max
175
194
min
-188
-209
max
188
209
min
-200
-222
max
200
222
min
-209
-232
max
209
232
-96/103-
MHz
ps
ps
ps
ps
ps
ps
ps
ps
ps
Rev.1.0 June 2016
AS4C128M32MD2-18BCN
AS4C128M32MD2-18BIN
Parameter
Cumulative error across 8 cycles
Cumulative error across 9 cycles
Cumulative error across 10 cycles
Cumulative error across 11 cycles
Cumulative error across 12 cycles
Cumulative error across n = 13, 14 . . .
49, 50cycles
Symbol
min/max min tCK
tERR(8per),
allowed
tERR(9per),
allowed
tERR(10per),
allowed
tERR(11per),
allowed
tERR(12per),
allowed
tERR(nper),
allowed
Speed Grade
1066
800
min
-217
-241
max
217
241
min
-224
-249
max
224
249
min
-231
-257
max
231
257
min
-237
-263
max
237
263
min
-242
-269
max
242
269
min
tERR(nper),allowed,min = (1 + 0.68ln(n))
* tJIT(per),allowed,min
max
tERR(nper),allowed,max = (1 + 0.68ln(n))
* tJIT(per),allowed,max
Unit
ps
ps
ps
ps
ps
ps
ZQ Calibration Parameters
Initialization Calibration Time
tZQINIT
min
1
us
Long Calibration Time
tZQCL
min
6
360
ns
Short Calibration Time
tZQCS
min
6
90
ns
Calibration Reset Time
tZQRESET
min
3
50
ns
Read Parameters
DQS output access time from CK/CK
tDQSCK
min
2500
max
5500
ps
DQSCK Delta Short
tDQSCKDS
max
330
450
ps
DQSCK Delta Medium
tDQSCKDM
max
680
900
ps
DQSCK Delta Long
tDQSCKDL
max
920
1200
ps
tDQSQ
max
200
240
ps
Data hold skew factor
tQHS
max
230
280
ps
DQS Output High Pulse Width
tQSH
min
tCH(abs) - 0.05
tCK(avg)
DQS Output Low Pulse Width
tQSL
min
tCL(abs) - 0.05
tCK(avg)
Data Half Period
tQHP
min
min(tQSH, tQSL)
tCK(avg)
tQH
min
tQHP - tQHS
ps
Read preamble
tRPRE
min
0.9
tCK(avg)
Read postamble
tRPST
min
tCL(abs) - 0.05
tCK(avg)
tLZ(DQS)
min
tDQSCK(MIN) - 300
ps
tLZ(DQ)
min
tDQSCK(MIN) - (1.4 * tQHS(MAX))
ps
DQS - DQ skew
DQ / DQS output hold time from DQS
DQS low-Z from clock
DQ low-Z from clock
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AS4C128M32MD2-18BCN
AS4C128M32MD2-18BIN
Parameter
DQS high-Z from clock
DQ high-Z from clock
Symbol
Speed Grade
min/max min tCK
1066
800
Unit
tHZ(DQS)
max
tDQSCK(MAX) - 100
ps
tHZ(DQ)
max
tDQSCK(MAX) + (1.4 * tDQSQ(MAX))
ps
Write Parameters
DQ and DM input hold time (Vref based)
tDH
min
210
270
ps
DQ and DM input setup time (Vref based)
tDS
min
210
270
ps
DQ and DM input pulse width
tDIPW
min
0.35
min
0.75
Write command to 1st DQS latching transition
tDQSS
max
1.25
DQS input high-level width
tDQSH
min
0.4
tCK(avg)
DQS input low-level width
tDQSL
min
0.4
tCK(avg)
DQS falling edge to CK setup time
tDSS
min
0.2
tCK(avg)
DQS falling edge hold time from CK
tDSH
min
0.2
tCK(avg)
Write postamble
tWPST
min
0.4
tCK(avg)
Write preamble
tWPRE
min
0.35
tCK(avg)
3
tCK(avg)
tCK(avg)
tCK(avg)
CKE Input Parameters
CKE min. pulse width
(high and low pulse width)
tCKE
min
3
CKE input setup time
tISCKE
min
0.25
tCK(avg)
CKE input hold time
tIHCKE
min
0.25
tCK(avg)
Command Address Input Parameters
Address and control input setup time
(Vref based)
tIS
min
220
290
ps
Address and control input hold time
(Vref based)
tIH
min
220
290
ps
tIPW
min
Address and control input pulse width
0.4
tCK(avg)
Mode Register Parameters
MODE REGISTER Write command period
tMRW
min
5
5
tCK(avg)
Mode Register Read command period
tMRR
min
2
2
tCK(avg)
LPDDR2 SDRAM Core Parameters
Read Latency
RL
min
3
8
6
tCK(avg)
Write Latency
WL
min
1
4
3
tCK(avg)
ACTIVE to ACTIVE command period
tRC
min
tCKESR
min
tXSR
min
CKE min. pulse width during Self-Refresh
(low pulse width during Self-Refresh)
Self refresh exit to next valid command delay
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tRAS + tRPab (with all-bank Precharge)
tRAS + tRPpb (with per-bank Precharge)
ns
3
15
ns
2
tRFCab + 10
ns
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AS4C128M32MD2-18BCN
AS4C128M32MD2-18BIN
Parameter
Exit power down to next valid command delay
Symbol
min/max min tCK
Speed Grade
1066
800
Unit
tXP
min
2
7.5
ns
CAS to CAS delay
tCCD
min
2
2
tCK(avg)
Internal Read to Precharge command delay
tRTP
min
2
7.5
ns
RAS to CAS Delay
tRCD
min
3
18
ns
Row Precharge Time(single bank)
tRPpb
min
3
18
ns
Row Precharge Time(all banks)
tRPab
8-bank
min
3
21
ns
min
3
42
ns
max
-
70
us
Row Active Time
tRAS
Write Recovery Time
tWR
min
3
15
ns
Internal Write to Read Command Delay
tWTR
min
2
7.5
ns
Active bank A to Active bank B
tRRD
min
2
10
ns
Four Bank Activate Window
tFAW
min
8
50
ns
Minimum Deep Power Down Time
tDPD
min
500
us
LPDDR2 Temperature De-Rating
tDQSCK De-Rating
Core Timings Temperature De-Rating
tDQSCK
(Derated)
max
tRCD
(Derated)
min
tRCD + 1.875
ns
tRC
(Derated)
min
tRC + 1.875
ns
tRAS
(Derated)
min
tRAS + 1.875
ns
tRP
(Derated)
min
tRP + 1.875
ns
tRRD
(Derated)
min
tRRD + 1.875
ns
5620
6000
ps
Boot Parameters (10 MHz - 55 MHz)
Clock Cycle Time
tCKb
min
18
max
100
ns
CKE Input Setup Time
tISCKEb
min
2.5
ns
CKE Input Hold Time
tIHCKEb
min
2.5
ns
Address & Control Input Setup Time
tISb
min
1150
ps
Address & Control Input Hold Time
tIHb
min
1150
ps
min
2
max
10
max
1.2
DQS Output Data Access Time from CK/CK
DQS - DQ skew
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tDQSCKb
tDQSQb
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ns
Rev.1.0 June 2016
AS4C128M32MD2-18BCN
AS4C128M32MD2-18BIN
Parameter
Symbol
Data Hold Skew Factor
Speed Grade
min/max min tCK
tQHSb
1066
max
Unit
800
1.2
ns
Notes for AC Electrical Characteristics
1. Frequency values are for reference only. Clock cycle time (tCK) is used to determine device capabilities.
2. All AC timings assume an input slew rate of 1 V/ns.
3. READ, WRITE, and input setup and hold values are referenced to VREF.
4. tDQSCKDS is the absolute value of the difference between any two tDQSCK measurements (in a byte lane) within a
contiguous sequence of bursts in a 160ns rolling window. tDQSCKDS is not tested and is guaranteed by design. Temperature drift in the system is < 10 ’C/s. Values do not include clock jitter. .
5. tDQSCKDM is the absolute value of the difference between any two tDQSCK measurements (in a byte lane) within a
1.6us rolling window. tDQSCKdm is not tested and is guaranteed by design. Temperature drift in the system is < 10 ‘C/s.
Values do not include clock jitter.
6. tDQSCKDL is the absolute value of the difference between any two tDQSCK measurements (in a byte lane) within a
32ms rolling window. tDQSCKDL is not tested and is guaranteed by design. Temperature drift in the system is < 10 ‘C/
s. Values do not include clock jitter.
7. For LOW-to-HIGH and HIGH-to-LOW transitions, the timing reference is at the point when the signal crosses the
transition threshold (VTT). tHZ and tLZ transitions occur in the same access time (with respect to clock) as valid data
transitions. These parameters are not referenced to a specific voltage level but to the time when the device output is no
longer driving (for tRPST, tHZ(DQS) and tHZ(DQ)), or begins driving (for tRPRE, tLZ(DQS), tLZ(DQ)). Figure shows a
method to calculate the point when device is no longer driving tHZ (DQS) and tHZ (DQ), or begins driving tLZ (DQS), tLZ
(DQ) by measuring the signal at two different voltages. The actual voltage measurement points are not critical as long as
the calculation is consistent.
VOH
X
VOH - X mV
2x X
VTT + 2x Y mV
VTT + Y mV
VOH - 2x X mV
tLZ(DQS), tLZ(DQ)
VTT
VTT
Y
actual waveform
2x Y
VTT - Y mV
tHZ(DQS), tHZ(DQ)
VOL + 2x X mV
VTT - 2x Y mV
VOL + X mV
T1 T2
VOL
T1 T2
stop driving point = 2 x T1 - T2
begin driving point = 2 x T1 - T2
HSUL_12 Driver Output Reference Load for Timing and Skew Rate
The parameters tLZ(DQS), tLZ(DQ), tHZ(DQS), and tHZ(DQ) are defined as single-ended. The timing parameters
tRPRE and tRPST are determined from the differential signal DQS-DQS.
8. Measured from the point when DQS, DQS begins driving the signal to the point when DQS, DQS begins driving the
first rising strobe edge.
9. Measured from the last falling strobe edge of DQS, DQS to the point when DQS, DQS finishes driving the signal.
10. CKE input setup time is measured from CKE reaching a HIGH/LOW voltage level to CK, CK crossing.
11. CKE input hold time is measured from CK, CK crossing to CKE reaching a HIGH/LOW voltage level.
12. Input set-up/hold time for signal (CA[9:0], CS).
13. To ensure device operation before the device is configured, a number of AC boot-timing parameters are defined in
this table. Boot parameter symbols have the letter b appended (for example, tCK during boot is tCKb).
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AS4C128M32MD2-18BCN
AS4C128M32MD2-18BIN
14. The LPDDR device will set some mode register default values upon receiving a RESET command as specified in
Mode Register Definition.
15. The output skew parameters are measured with default output impedance settings using the reference load.
16. The minimum tCK column applies only when tCK is greater than 6ns.
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AS4C128M32MD2-18BCN
AS4C128M32MD2-18BIN
Package Diagram
134-Ball FBGA - 11.5mm x 11.5mm 0.65mm pitch
Unit: mm
* BSC (Basic Spacing between Center)
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AS4C128M32MD2-18BCN
AS4C128M32MD2-18BIN
PART NUMBERING SYSTEM
B
AS4C
128M32MD2
18
DRAM
128M32=128Mx32
MD2=LPDDR2
18=533MHz
B = FBGA
C/I
C=Commercial
(-25° C~+85° C)
I = Industrial
(-40° C~+85° C)
N
Indicates Pb and
Halogen Free
Alliance Memory, Inc.
511 Taylor Way,
San Carlos, CA 94070
Tel: 650-610-6800
Fax: 650-620-9211
www.alliancememory.com
Copyright © Alliance Memory
All Rights Reserved
© Copyright 2007 Alliance Memory, Inc. All rights reserved. Our three-point logo, our name and
Intelliwatt are trademarks or registered trademarks of Alliance. All other brand and product names
may be the trademarks of their respective companies. Alliance reserves the right to make changes
to this document and its products at any time without notice. Alliance assumes no responsibility for
any errors that may appear in this document. The data contained herein represents Alliance's best
data and/or estimates at the time of issuance. Alliance reserves the right to change or correct this
data at any time, without notice. If the product described herein is under development, significant
changes to these specifications are possible. The information in this product data sheet is intended
to be general descriptive information for potential customers and users, and is not intended to
operate as, or provide, any guarantee or warrantee to any user or customer. Alliance does not
assume any responsibility or liability arising out of the application or use of any product described
herein, and disclaims any express or implied warranties related to the sale and/or use of Alliance
products including liability or warranties related to fitness for a particular purpose, merchantability,
or infringement of any intellectual property rights, except as express agreed to in Alliance's Terms
and Conditions of Sale (which are available from Alliance). All sales of Alliance products are made
exclusively according to Alliance's Terms and Conditions of Sale. The purchase of products from
Alliance does not convey a license under any patent rights, copyrights; mask works rights,
trademarks, or any other intellectual property rights of Alliance or third parties. Alliance does not
authorize its products for use as critical components in life-supporting systems where a
malfunction or failure may reasonably be expected to result in significant injury to the user, and the
inclusion of Alliance products in such life-supporting systems implies that the manufacturer
assumes all risk of such use and agrees to indemnify Alliance against all claims arising from such
use.
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