EOREX EM44CM1688LBA-25F

eorex
EM44CM1688LBA
1Gb (8M×8Bank×16)
Double DATA RATE 2 SDRAM
Features
Description
• JEDEC Standard VDD/VDDQ=1.8V ± 0.1V.
• All inputs and outputs are compatible with
SSTL_18 interface.
• Fully differential clock inputs (CK,/CK) operation.
• 8 Banks
• Posted CAS
• Burst Length: 4 and 8.
• Programmable CAS Latency (CL): 3, 4 and 5.
• Programmable Additive Latency (AL):
0, 1, 2, 3 and 4.
• Write Latency (WL) =Read Latency (RL) -1.
• Read Latency (RL) = Programmable Additive
Latency (AL) + CAS Latency (CL)
• Bi-directional Differential Data Strobe (DQS).
• Data inputs on DQS centers when write.
• Data outputs on DQS, /DQS edges when read.
• On chip DLL align DQ, DQS and /DQS transition
with CK transition.
• DM mask write data-in at the both rising and falling
edges of the data strobe.
• Sequential & Interleaved Burst type available.
• Off-Chip Driver (OCD) Impedance Adjustment
• On Die Termination (ODT)
• Auto Refresh and Self Refresh
• 8,192 Refresh Cycles / 64ms
• Average Refresh Period 7.8us at lower than Tcase
85°C, 3.9us at 85°C < Tcase ≦ 95°C
• RoHS Compliance
• Partial Array Self-Refresh (PASR)
• High Temperature Self-Refresh rate enable
The EM44CM1688LBA is a high speed Double Date
Rate 2 (DDR2) Synchronous DRAM fabricated with
ultra high performance CMOS process containing
1,073,741,824 bits which organized as 8Mbits x 8
banks by 16 bits.
This synchronous device achieves high speed
double-data-rate transfer rates of up to 667
Mb/sec/pin (DDR2-667) for general applications.
The chip is designed to comply with the following
key DDR2 SDRAM features: (1) posted CAS with
additive latency, (2) write latency = read latency -1,
(3) Off-Chip Driver (OCD) impedance adjustment
and On Die Termination (4) normal and weak
strength data output driver.
All of the control and address inputs are
synchronized with a pair of externally supplied
differential clocks. Inputs are latched at the cross
point of differential clocks (CK rising and /CK falling).
All I/Os are synchronized with a pair of bidirectional
strobes (DQS and /DQS) in a source synchronous
fashion. The address bus is used to convey row,
column and bank address information in a /RAS and
/CAS multiplexing style.
The 1Gb DDR2 device operates with a single power
supply: 1.8V ± 0.1V VDD and VDDQ.
Available package: TFBGA-84Ball (13mmx9mm,
0.8mm x 0.8mm ball pitch).
Ordering Information
Part No
EM44CM1688LBA-25F
Organization
Max. Freq
Package
Grade
Pb
64M X 16
tCK 5: DDR2-800Mhz 5-5-5
TFBGA-84
Commercial
Free
( Note )
Ball
Note : Speed ( tCK *) is in order of CL-tRCD-tRP
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EM44CM1688LBA
* EOREX reserves the right to change products or specification without notice.
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EM44CM1688LBA
Pin Assignment: Top View
1
2
3
7
8
9
VDD
NC
VSS
A
VSSQ
/UDQS
VDDQ
DQ14(UDQ6)
VSSQ
UDM
B
UDQS
VSSQ
DQ15(UDQ7)
VDDQ
DQ9(UDQ1)
VDDQ
C
VDDQ
DQ8(UDQ0)
VDDQ
DQ12(UDQ4)
VSSQ
DQ11(UDQ3)
D
DQ10(UDQ2)
VSSQ
DQ13(UDQ5)
VDD
NC
VSS
E
VSSQ
/LDQS
VDDQ
DQ6(LDQ6)
VSSQ
LDM
F
LDQS
VSSQ
DQ7(LDQ7)
VDDQ
DQ1(LDQ1)
VDDQ
G
VDDQ
DQ0(LDQ0)
VDDQ
DQ4(LDQ4)
VSSQ
DQ3(LDQ3)
H
DQ2(LDQ2)
VSSQ
DQ5(LDQ5)
VDDL
VREF
VSS
J
VSSDL
CK
VDD
CKE
/WE
K
/RAS
/CK
ODT
BA0
BA1
L
/CAS
/CS
A10/AP
A1
M
A2
A0
A3
A5
N
A6
A4
A7
A9
P
A11
A8
A12
NC
R
NC
NC
BA2
VSS
VDD
VDD
VSS
84ball TFBGA / (13.0mm x 9mm x 1.2mm)
Note:
1. VDDL and VSSDL are power and ground for the DLL.
2. In case of only 8 DQs out of 16 DQs are used, LDQS, LDQSB and DQ0~7 must be used.
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EM44CM1688LBA
Pin Description (Simplified)
Pin
Name
J8,K8
CK,/CK
L8
/CS
K2
CKE
M8,M3,M7,N2,N8,
N3,N7,P2,P8,P3,
M2,P7,R2
A0~12
L2,L3,L1
BA0, BA1,BA2
K9
ODT
K7, L7, K3
/RAS, /CAS,
/WE
B7,A8,F7,E8
UDQS,/UDQS,
LDQS,/LDQS
Function
(System Clock)
CK and CK are differential clock inputs. All address and control
input signals are sampled on the crossing of the positive edge of
CK and negative edge of CK. Output (read) data is referenced to
the crossings of CK and CK (both directions of crossing).
(Chip Select)
All commands are masked when CS is registered HIGH. CS
provides for external Rank selection on systems with multiple
Ranks. CS is considered part of the command code.
(Clock Enable)
CKE high activates and CKE low deactivates internal clock signals
and device input buffers and output drivers. Taking CKE low
provides Precharge Power-Down and Self- Refresh operation (all
banks idle), or Active Power-Down (row Active in any bank). CKE
is synchronous for power down entry and exit and for Self-Refresh
entry. CKE is asynchronous for Self-Refresh exit. CKE must be
maintained high throughout read and write accesses. Input buffers,
excluding CK, CK, ODT and CKE are disabled during Power Down.
Input buffers, excluding CKE are disabled during Self-Refresh.
(Address)
Provided the row address for Active commands and the column
address and Auto Precharge bit for Read/Write commands to
select one location out of the memory array in the respective bank.
A10 is sampled during a Precharge command to determine
whether the Precharge applies to one bank (A10 LOW) or all banks
(A10 HIGH). If only one bank is to be precharged.
A0~A12:Row address ; A0~9 :Column address.
The address inputs also provide the op-code during Mode Register
Set commands.
(Bank Address)
BA0 – BA2 define to which bank an Active, Read, Write or
Precharge command is being applied (For 256Mb and 512Mb, BA2
is not applied). Bank address also determines if the mode register
or extended mode register is to be accessed during a MRS or
EMRS cycle.
(On Die Termination)
ODT (registered HIGH) enables termination resistance internal to
the DDR2 SDRAM. When enabled, ODT is applied to each DQ,
UDQS/UDQS, LDQS/LDQS, UDM, and LDM signal. The ODT pin
will be ignored if the Extended Mode Register (EMRS(1)) is
programmed to disable ODT.
(Command Inputs)
/RAS, /CAS and /WE (along with /CS) define the command being
entered.
(Data Strobe)
Output with read data, input with write data. Edge-aligned with read
data, centered in write data. LDQS corresponds to the data on
DQ0-DQ7; UDQS corresponds to the data on DQ8-DQ15. The
data strobes LDQS and UDQS may be used in single ended mode
or paired with optional complementary signals /LDQS and /UDQS
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B3,F3
G8,G2,H7,H3,H1,
H9,F1,F9,C8,
C2,D7,D3,D1,
D9,B1,B9
A1,E1,J9,M9,R1/
A3,E3,J3,N1,P9
A9,C1,C3,C7,C9,E
9,G1,G3,G7,G9/
A7,B2,B8,D2,D8,E
7,F2,F8,H2,H8
EM44CM1688LBA
UDM,LDM
DQ0~15
VDD/VSS
to provide differential pair signaling to the system during both reads
and writes. An EMRS(1) control bit enables or disables all
complementary data strobe signals. In this data sheet, "differential
DQS signals" refers to A10 = 0 of EMRS(1) using LDQS/LDQS and
UDQS/UDQS. "single-ended DQS signals" refers to A10 = 1 of
EMRS(1) using LDQS and UDQS.
(Input Data Mask)
DM is an input mask signal for write data. Input data is masked
when DM is sampled HIGH coincident with that input data during a
Write access. DM is sampled on both edges of DQS. Although DM
pins are input only, the DM loading matches the DQ and DQS
loading.
(Data Input/Output)
Data inputs and outputs are on the same pin.
(Power Supply/Ground)
VDD and VSS are power supply for internal circuits.
VDDQ/VSSQ
(DQ Power Supply/DQ Ground)
VDDQ and VSSQ are power supply for the output buffers.
J1/J7
VDDL/VSSDL
J2
VREF
A2,E2,L1,R3,R7,
R8
NC
(DLL Power Supply/DLL Ground)
VDDL and VSSDL are power supply for DLL circuits
(Reference Voltage)
SSTL_1.8 reference voltage
(No Connection)
No internal electrical connection is present.
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EM44CM1688LBA
Absolute Maximum Rating
Symbol
Item
Rating
Units
VIN, VOUT
Input, Output Voltage
-0.5 ~ +2.3
V
VDD, VDDQ,
Power Supply Voltage
-0.5 ~ +2.3
V
VDDL,
DLL Power Supply Voltage
-0.5 ~ +2.3
V
TOP
Operating Temperature Range
0 ~ +85
°C
TSTG
Storage Temperature Range
-55 ~ +100
°C
1
W
PD
Power Dissipation
IOS
Short Circuit Current
50
mA
Note: Caution Exposing the device to stress above those listed in Absolute Maximum Ratings could
cause permanent damage. The device is not meant to be operated under conditions outside the
limits described in the operational section of this specification. Exposure to Absolute Maximum
Rating conditions for extended periods may affect device reliability.
Capacitance (VCC=1.8V ± 0.1V, f=1MHz, TA=25°C)
Symbol
CCK
CDCK
CI
CDI
CIO
CDIO
Parameter
DDR2-667/533
DDR2-800
Units
Min.
Max.
Min.
Max.
1.0
2.0
1.0
2.0
pF
-
0.25
-
0.25
pF
1.0
2.0
1.0
1.75
pF
-
0.25
-
0.25
pF
2.5
4
2.5
3.5
pF
-
0.5
-
0.5
pF
Input Capacitance of CK, /CK
Input Capacitance delta of CK, /CK
Input Capacitance for others: CKE,
Address, /CS, /RAS, /CAS, /WE
Input Capacitance delta for others
Input/Output Capacitance
DQ, DM, DQS, DQS, RDQS,
RDQS
Input/Output Capacitance delta
Recommended DC Operating Conditions (TA=0°C ~85°C)
Symbol
Parameter
Min.
Typ.
Max.
Units
Power Supply Voltage
1.7
1.8
1.9
V
VDDDL
Power Supply for DLL Voltage
1.7
1.8
1.9
V
VDDQ
Power Supply for Output Voltage
1.7
1.8
1.9
V
VDD
VREF
Input Reference Voltage
0.49* VDDQ
0.5* VDDQ
VTT
Termination Voltage
VREF - 0.04
VREF
0.25
VID
VIH
V
V
-
VDDQ+0.6
V
VREF +0.125
-
VDDQ+0.3
V
-0.3
-
VREF - 0.125
V
DC differential Input Voltage
Input Logic High Voltage
0.51* VDDQ
VREF +0.04
VIL
Input Logic Low Voltage
Note: * All voltages referred to VSS.
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EM44CM1688LBA
Recommended DC Operating Conditions
(VDD=1.8V±0.1V, TA=0°C ~ 85°C)
Symbol
Parameter
Test Conditions
-5
3-3-3
Max.
-37
4-4-4
Max.
-3
5-5-5
Max.
Units
IDD1
(Note 1)
Burst length=2,
tRC≥tRC(min.), IOL=0mA,
One bank active
100
115
115
mA
IDD2P
Precharge Standby
Current in Power
Down Mode
CKE≤VIL(max.), tCK=min
10
10
10
mA
IDD2N
Precharge Standby
Current in Non-power
Down Mode
CKE≥VIH(min.), tCK=min,
/CS≥VIH(min.)
Input signals SWITCHING
65
70
80
mA
CKE≤VIL(max.), tCK=min
26
30
30
mA
CKE≤VIL(max.), tCK=min
13
13
13
mA
IDD3P
IDD3P
Operating Current
Active Standby
Current in Power
Down Mode (A12=0)
Active Standby
Current in Power
Down Mode (A12=1)
IDD3N
Active Standby
Current in Non-power
Down Mode
CKE≥VIH(min.), tCK=min,
/CS≥VIH(min.)
Input signals SWITCHING
60
67
70
mA
IDD4
Operating Current
(Note 2)
(Burst Mode)
tCK ≥ tCK(min.), IOL=0mA,
All banks active
135
155
170
mA
IDD5
Refresh Current
(Note 3)
(Burst Mode)
tRC≥ tRFC (min.), All banks
active
165
175
175
mA
IDD6
Self Refresh Current
CKE≤0.2V
11
11
11
mA
IDD7
Operating Current
All bank Interleave read
230
245
250
mA
*All voltages referenced to VSS.
Note 1: IDD1 depends on output loading and cycle rates. (CL=CL min. AL=0)
Note 2: IDD4 depends on output loading and cycle rates.
Input signals SWITCHING.
Note 3: Min. of tRFC (Auto refresh Row Cycle Times) is shown at AC Characteristics.
Recommended DC Operating Conditions (Continued)
Symbol
Parameter
Test Conditions
IIL
Input Leakage Current
IOL
Output Leakage Current
0≤VI≤VDDQ, VDDQ=VDD
All other pins not under
test=0V
0≤VO≤VDDQ, DOUT is disabled
VOH
High Level Output Voltage
IO=-13.4mA
VOL
Low Level Output Voltage
IO=+13.4mA
Feb. 2009
Min.
Max.
Units
-2
+2
uA
-5
+5
uA
VTT+0.603
V
VTT-0.603
V
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EM44CM1688LBA
Block Diagram
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EM44CM1688LBA
OCD Default Setting Table
Symbol
Parameter
Min.
Typ.
Max.
Units
-
Output Impedance
-
-
23.4
Ω
-
Pull-up / Pull down mismatch
Output Impedance step size for
OCD calibration
Output Slew Rate
0
-
4
Ω
0
-
1.5
Ω
+1.5
-
5.0
V/ns
-
AC Operating Test Conditions
(VDD=1.8V ± 0.1V, TA=0°C ~85°C)
Symbol
Item
VSWING(max)
Conditions
Input Signal maximum peak to peak swing
SLEW
Input Signals minimum slew rate
1.0 V/ns
VREF
Input Reference Level
0.5*VDDQ
1.0
V
AC Operating Test Conditions(Continued)
Symbol
Parameter
Min.
Max.
Units
VID
AC differential Input Voltage
0.5
VDDQ+0.6
V
VIX
AC differential corss point Input Voltage
0.5*VDDQ - 0.175
0.5*VDDQ + 0.175
V
VOX
AC differential corss point Output Voltage
0.5*VDDQ - 0.125
0.5*VDDQ + 0.125
V
VOH
High Level Output Voltage
VTT+0.603
-
V
VOL
Low Level Output Voltage
-
VTT-0.603
V
Symbol
Parameter
VIH
VIL
DDR2-667/533
DDR2-800
Units
Min.
Max.
Min.
Max.
Input Logic High Voltage
VREF + 0.25
-
VREF + 0.2
-
V
Input Logic Low Voltage
-
VREF - 0.25
-
VREF - 0.2
V
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EM44CM1688LBA
AC Operating Test Characteristics
(VDD=1.8V±0.1V, TA=0°C ~85°C)
Symbol
tDQCK
tDQSCK
tCL,tCH
tCK
tDS
tDH
Parameter
DQ output access from
CLK,/CLK
DQS output access time from
CLK,/CLK
CL low/high level width
CAS Latency
=5
Clock Cycle
CAS Latency
Time
=4
CAS Latency
=3
DQ and DM setup time
Min.
-25
Max.
-0.4
+0.4
ns
-0.35
+0.35
ns
0.48
0.52
tCK
2.5
8
ns
3.75
8
ns
5
8
ns
50
-
ps
125
-
ps
0.35
-
tCK
-0.4
+0.4
ns
-0.4
+0.4
ns
-
0.2
ns
Units
tWPRES
DQ and DM hold time
DQ and DM input pulse width
for each input
Data out high impedance time
from CLK,/CLK
Data out low impedance time
from CLK,/CLK
DQS-DQ skew for associated
DQ signal
Data hold skew factor
Write command to first
latching DQS transition
DQS Low/High input pulse
width
DQS input valid window
Mode Register Set command
cycle time
Write Preamble setup time
tWPRE
Write Preamble
0.35
-
tCK
tWPST
Write Postamble
Address/control input setup
time
Address/control input hold
time
Read Preamble
0.4
0.6
tCK
0.175
-
ns
0.25
-
ns
0.9
1.1
tCK
tDIPW
tHZ
tLZ
tDQSQ
tQSH
tDQSS
tDQSL,tDQSH
tDSL,tDSH
tMRD
tIS
tIH
tRPRE
-
0.34
ns
WL
-0.25
WL
+0.25
tCK
0.35
-
tCK
0.2
-
tCK
2
-
tCK
0
-
ns
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EM44CM1688LBA
AC Operating Test Characteristics (Continued)
(VDD=1.8V±0.1V, TA=0°C ~85°C)
Symbol
Parameter
-3
Unit
Min.
0.4
Max.
0.6
tCK
45
70K
ns
tRPST
Read Postamble
tRAS
Active to Precharge command period
tRC
Active to Active command period
57.5
-
ns
tRFC
Auto Refresh Row Cycle Time
127.5
-
ns
tRCD
Active to Read or Write delay
12.5
-
ns
tRP
Precharge command period
12.5
-
ns
tRRD
Active bank A to B command period
10
-
ns
tCCD
Column address to column address
delay
2
-
tCK
15
tRP+
tWR
200
137.5
-
ns
-
tCK
-
tCK
ns
2
-
tCK
8-AL
-
tCK
2
-
tCK
7.5
7.5
-
ns
ns
3
-
tCK
-
tCK
-
tCK
tWR
tWTR
tRTP
Write recovery time
Auto Pre-charge write recovery +
pre-charge time
Exit self refresh to Read command
Exit self refresh to non-read command
Exit active power-down mode to Read
command (Fast exit)
Exit active power-down mode to Read
command (Slow exit)
Exit pre-charge power-down to any
non-read command
Internal Write to Read command delay
Internal Read to pre-charge delay
tCKE
CKE minimum pulse width
tDAL
tXSRD
tXSNR
tXARD
tXARDS
tXP
tWPD
Write to pre-charge delay(same bank)
WL+
BL/2 +
tRPD
Read to pre-charge delay(same bank)
AL+
BL/2+1
tOIT
OCD drive mode output delay
0
12
ns
tREFI
Average periodic refresh interval
-
7.8
us
tWR
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EM44CM1688LBA
AC Operating Test Characteristics (Continued)
(VDD=1.8V±0.1V, TA=0°C ~85°C)
Symbol
Parameter
-3
Unit
Min.
Max.
tAOND
ODT turn-on delay
2
tAOFD
ODT turn-off delay
2.5
(Note 1)
tAC
(MIN)
ODT turn-off
(Note 2)
tAC
(MIN)
tAONPD
ODT turn-on (Power-Down Modes)
tAC
(MIN)
+ 2ns
tAOFPD
ODT turn-off (Power-Down Modes)
tAC
(MIN)
+ 2ns
tAON
ODT turn-on
tAOF
tANPD
tAXPD
ODT to Power Down Mode Entry
Latency
ODT Power Down Exit Latency
tCK
tCK
tAC
(MAX)
+ 0.7
tAC
(MAX)
+ 0.6
2Tck+
tAC
(MAX)
+ 1ns
2.5Tck
+
tAC
(MAX)
+ 1ns
ns
ns
ns
ns
3
-
tCK
8
-
tCK
Note 1: ODT turn on time min is when the device leaves high impedance and ODT resistance begins to turn on.
ODT turn on time max is when the ODT resistance is fully on. Both are measure from tAOND.
Note 2: ODT turn off time min is when the device starts to turn off ODT resistance
ODT turn off time max is when the bus is in high impedance. Both are measured from tAOFD.
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EM44CM1688LBA
Simplified State Diagram
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EM44CM1688LBA
1. Command Truth Table
Command
Symbol
CKE
n-1
n
/CS
/RAS
/CAS
/WE
BA0,
BA1
A10
A12~A0
Ignore Command
DESL
H
X
H
X
X
X
X
X
X
No Operation
NOP
H
X
L
H
H
H
X
X
X
READ
H
H
L
H
L
H
V
L
V
READA
H
H
L
H
L
H
V
H
V
WRIT
H
H
L
H
L
L
V
L
V
WRITA
H
H
L
H
L
L
V
H
V
ACT
H
H
L
L
H
H
V
V
V
Read
Read with Auto Pre-charge
Write
Write with Auto Pre-charge
Bank Activate
Pre-charge Select Bank
PRE
H
H
L
L
H
L
V
L
X
Pre-charge All Banks
PALL
H
H
L
L
H
L
X
H
X
(E)MRS H H
L
L
L
L
V
V
H = High level, L = Low level, X = High or Low level (Don't care), V = Valid data input
V
(Ext.) Mode Register Set
2. CKE Truth Table
Item
Command
Symbol
Idle
CBR Refresh Command
REF
Idle
Self Refresh Entry
SELF
Self Refresh
Self Refresh Exit
Idle
Power Down Entry
Power Down
Power Down Exit
CKE
n-1 n
H H
/CS
/RAS
/CAS
/WE
Addr.
L
L
L
H
X
H
L
L
L
L
L
H
X
H
L
H
H
H
X
L
H
H
X
X
X
X
H
L
H
X
X
X
X
H
L
L
H
H
H
X
L
H
H
X
X
X
X
H
H
H
X
L
H
L
Remark H = High level, L = Low level, X = High or Low level (Don't care)
Feb. 2009
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EM44CM1688LBA
3. Operative Command Table
Current
State
Idle
Row
Active
/CS
/R
/C
/W
Addr.
Command
H
X
X
X
X
DESL
NOP
L
H
H
H
X
NOP
NOP
L
H
H
L
X
TERM
NOP
L
H
L
X
BA/CA/A10
READ/WRIT/BW
ILLEGAL
(Note 1)
Bank active,Latch RA
L
L
H
H
BA/RA
ACT
L
L
H
L
BA, A10
PRE/PREA
L
L
L
H
REFA
L
L
L
L
MRS
Mode register
H
L
X
H
X
H
X
H
X
Op-Code,
Mode-Add
X
X
NOP
(Note 4)
Auto refresh
DESL
NOP
L
H
H
L
BA/CA/A10
READ/READA
L
H
L
L
BA/CA/A10
WRIT/WRITA
NOP
NOP
Begin read,Latch CA,
Determine auto-precharge
Begin write,Latch CA,
Determine auto-precharge
L
L
H
H
BA/RA
ACT
L
L
H
L
BA/A10
PRE/PREA
L
L
L
H
REFA
ILLEGAL
L
L
L
L
MRS
ILLEGAL
H
L
L
X
H
H
X
H
H
X
H
L
X
Op-Code,
Mode-Add
X
X
X
DESL
NOP
TERM
L
H
L
H
BA/CA/A10
READ/READA
L
L
H
H
BA/RA
ACT
L
L
L
L
H
L
L
H
PRE/PREA
REFA
L
L
L
L
H
L
L
X
H
H
X
H
H
X
H
L
BA, A10
X
Op-Code,
Mode-Add
X
X
X
L
H
L
H
BA/CA/A10
READ/READA
Read
Write
Action
MRS
DESL
NOP
TERM
L
H
L
L
BA/CA/A10
WRIT/WRITA
L
L
H
H
BA/RA
ACT
L
L
H
L
BA, A10
PRE/PREA
L
L
L
L
L
L
H
L
X
Op-Code,
REFA
MRS
Feb. 2009
(Note 3)
(Note 1)
ILLEGAL
Precharge/Precharge all
NOP(Continue burst to end)
NOP(Continue burst to end)
Terminal burst
Terminate burst,Latch CA,
Begin new read,
Determine Auto-precharge
ILLEGAL
(Note 1)
Terminate burst, PrecharE
ILLEGAL
ILLEGAL
NOP(Continue burst to end)
NOP(Continue burst to end)
ILLEGAL
Terminate burst with DM=”H”,Latch
CA,Begin read,Determine
(Note 2)
auto-precharge
Terminate burst,Latch CA,Begin
new write, Determine
(Note 2)
auto-precharge
ILLEGAL
(Note 1)
Terminate burst with DM=”H”,
Precharge
ILLEGAL
ILLEGAL
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eorex
EM44CM1688LBA
3. Operative Command Table (Continued)
Current
State
Read with
AP
Write with AP
Pre-charging
Row
Activating
/CS
/R
/C
/W
Addr.
Command
H
L
L
L
X
H
H
H
X
H
H
L
X
H
L
X
X
X
BA/CA/A10
BA/RA
DESL
NOP
TERM
READ/WRITE
L
L
H
H
BA/A10
ACT
ILLEGAL
(Note 1)
L
L
L
L
H
L
L
H
PRE/PREA
REFA
ILLEGAL
ILLEGAL
(Note 1)
L
L
L
L
MRS
ILLEGAL
H
L
L
L
X
H
H
H
X
H
H
L
X
H
L
X
X
X
Op-Code,
Mode-Add
X
X
X
BA/CA/A10
DESL
NOP
TERM
READ/WRITE
L
L
H
H
BA/RA
ACT
ILLEGAL
(Note 1)
L
L
L
L
H
L
L
H
PRE/PREA
REFA
ILLEGAL
ILLEGAL
(Note 1)
L
L
L
L
MRS
ILLEGAL
H
L
L
L
X
H
H
H
X
H
H
L
X
H
L
X
BA/A10
X
Op-Code,
Mode-Add
X
X
X
BA/CA/A10
DESL
NOP
TERM
READ/WRITE
L
L
H
H
BA/RA
ACT
L
L
L
L
H
L
L
H
PRE/PREA
REFA
L
L
L
L
H
L
L
L
X
H
H
H
X
H
H
L
X
H
L
X
BA/A10
X
Op-Code,
Mode-Add
X
X
X
BA/CA/A10
DESL
NOP
TERM
READ/WRITE
L
L
H
H
BA/RA
ACT
ILLEGAL
(Note 1)
L
L
L
L
H
L
L
H
PRE/PREA
REFA
ILLEGAL
ILLEGAL
(Note 1)
L
L
L
L
BA/A10
X
Op-Code,
Mode-Add
MRS
ILLEGAL
MRS
Action
NOP(Continue burst to end)
NOP(Continue burst to end)
ILLEGAL
(Note 1)
ILLEGAL
NOP(Continue burst to end)
NOP(Continue burst to end)
ILLEGAL
(Note 1)
ILLEGAL
NOP(idle after tRP)
NOP(idle after tRP)
NOP
(Note 1)
ILLEGAL
(Note 1)
ILLEGAL
(Note 3)
NOP(idle after tRP)
ILLEGAL
ILLEGAL
NOP(Row active after tRCD)
NOP(Row active after tRCD)
NOP
(Note 1)
ILLEGAL
Remark H = High level, L = Low level, X = High or Low level (Don't care), AP = Auto Pre-charge
Feb. 2009
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EM44CM1688LBA
3. Operative Command Table (Continued)
Current State
Write
Recovering
Refreshing
/CS
/R
/C
/W
Addr.
Command
H
L
L
L
X
H
H
H
X
H
H
L
X
H
L
H
X
X
X
BA/CA/A10
DESL
NOP
TERM
READ
L
H
L
L
BA/CA/A10
WRIT/WRITA
L
L
H
H
BA/RA
ACT
ILLEGAL
(Note 1)
L
L
L
L
H
L
L
H
PRE/PREA
REFA
ILLEGAL
ILLEGAL
(Note 1)
L
L
L
L
MRS
ILLEGAL
H
L
L
L
L
L
L
X
H
H
H
L
L
L
X
H
H
L
H
H
L
X
H
L
X
H
L
H
L
L
L
L
BA/A10
X
Op-Code,
Mode-Add
X
X
X
BA/CA/A10
BA/RA
BA/A10
X
Op-Code,
Mode-Add
DESL
NOP
TERM
READ/WRIT
ACT
PRE/PREA
REFA
MRS
Action
NOP
NOP
NOP
(Note 1)
ILLEGAL
New write, Determine AP
NOP(idle after tRP)
NOP(idle after tRP)
NOP
ILLEGAL
ILLEGAL
NOP(idle after tRP)
ILLEGAL
ILLEGAL
Remark H = High level, L = Low level, X = High or Low level (Don't care), AP = Auto Pre-charge
Note 1: ILLEGAL to bank in specified states;
Function may be legal in the bank indicated by Bank Address (BA), depending on the state of
that bank.
Note 2: Must satisfy bus contention, bus turn around, and/or write recovery requirements.
Note 3: NOP to bank precharging or in idle state.May precharge bank indicated by BA.
Note 4: ILLEGAL of any bank is not idle.
Feb. 2009
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EM44CM1688LBA
4. Command Truth Table for CKE
Current State
Self Refresh
Both bank
precharge
power down
All Banks
Idle
Any State Other
than Listed above
CKE
n-1
n
/CS
/R
/C
/W
Addr.
Action
INVALID
Exist Self-Refresh
Exist Self-Refresh
ILLEGAL
ILLEGAL
ILLEGAL
NOP(Maintain self refresh)
INVALID
Exist Power down
Exist Power down
ILLEGAL
ILLEGAL
ILLEGAL
NOP(Maintain Power down)
Refer to function true table
(Note 3)
Enter power down mode
(Note 3)
Enter power down mode
ILLEGAL
ILLEGAL
Row active/Bank active
(Note 3)
Enter self-refresh
Mode register access
Special mode register access
H
L
L
L
L
L
L
H
L
L
L
L
L
L
H
H
X
H
H
H
H
H
L
X
H
H
H
H
H
L
H
L
X
H
L
L
L
L
X
X
H
L
L
L
L
X
X
H
X
X
H
H
H
L
X
X
X
H
H
H
L
X
X
X
X
X
H
H
L
X
X
X
X
H
H
L
X
X
X
X
X
X
H
L
X
X
X
X
X
H
L
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
H
H
H
H
H
H
H
L
L
L
L
L
L
L
L
L
L
L
L
L
L
H
H
H
L
L
L
L
H
H
L
H
L
L
L
H
L
X
H
H
L
L
X
X
X
RA
X
Op-Code
Op-Code
L
X
X
X
X
X
X
Refer to current state
H
H
X
X
X
X
X
Refer to command truth table
Remark: H = High level, L = Low level, X = High or Low level (Don't care)
Notes 1: After CKE’s low to high transition to exist self refresh mode.And a time of tRC(min) has to be
Elapse after CKE’s low to high transition to issue a new command.
Notes 2:CKE low to high transition is asynchronous as if restarts internal clock.
Notes 3:Power down and self refresh can be entered only from the idle state of all banks.
Feb. 2009
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EM44CM1688LBA
Initialization
The following sequence is required for power-up and initialization and is shown in below Figure:
1. Apply power and attempt to maintain CKE below 0.2 * VDDQ and ODT at a low state (all other inputs may
be undefined). To guarantee ODT off, VREF must be valid and a low level must be applied to the ODTpin.
- VDD,VDDL and VDDQ are driven from a single power converter output, AND
VTT is limited to 0.95 V max, AND VREF tracks VDDQ/2 or
- Apply VDD before or at the same time as VDDL; Apply VDDL before or at the same time as VDDQ;
Apply VDDQ before or at the same time as VTT & VREF.
at least one of these two sets of conditions must be met.
2. Start clock (CK, /CK) and maintain stable power and clock condition for a minimum of 200 µs.
3. Apply NOP or Deselect commands & take CKE high.
4. Wait minimum of 400ns, then issue a Precharge-all command.
5. Issue Reserved command EMRS(2) or EMRS(3).
6. Issue EMRS(1) command to enable DLL. (A0=0 and BA0=1 and BA1=0)
7. Issue MRS command (Mode Register Set) for "DLL reset". (A8=1 and BA0=BA1=0)
8. Issue Precharge-All command.
9. Issue 2 or more Auto-Refresh commands.
10. Issue a MRS command with low on A8 to initialize device operation. (without resetting the DLL)
11. At least 200 clocks after step 8, execute OCD Calibration (Off Chip Driver impedance adjustment). If
OCD calibration is not used, EMRS OCD Default command (A9=A8=A7=1) followed by EMRS(1) OCD
Calibration Mode Exit command (A9=A8=A7=0) must be issued with other parameters of EMRS(1).
12. The DDR2 SDRAM is now initialized and ready for normal operation.
Feb. 2009
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EM44CM1688LBA
Mode Register Definition
Mode Register Set
The mode register stores the data for controlling the various operating modes of DDR2 SDRAM which
contains addressing mode, burst length, /CAS latency, WR (write recovery), test mode, DLL reset and
various vendor’s specific opinions. The defaults values of the register is not defined, so the mode register
must be written after power up for proper DDR2 SDRAM operation. The mode register is written by asserting
low on /CS, /RAS, /CAS, /WE and BA0/1. The state of the address pins A0-A12 in the same cycle as /CS,
/RAS, /CAS, /WE and BA0,1 going low is written in the mode register. Two clock cycles are requested to
complete the write operation in the mode register. The mode register contents can be changed using the
same command and clock cycle requirements during operating as long as all banks are in the idle state. The
mode register is divided into various fields depending on functionality. The burst length uses A0-A2,
addressing mode uses A3, /CAS latency ( read latency from column address ) uses A4-A6. A7 is used for
test mode. A8 is used for DDR reset. A9 ~ A11 are used for write recovery time (WR) ,A7 must be set to low
for normal MRS operation. With address bit A12 two Power-Down modes can be selected, a “standard
mode” and a “low-power” Power-Down mode.
Feb. 2009
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EM44CM1688LBA
Address input for Mode Register Set ( MRS )
BA1
BA0
A12
0
0
PD
A11
A10
A9
WR
A8
A7
DLL
TM
DLL Rest A8
A6
A3
Mode
A2
BT
A1
A0
Burst Length
A7
Burst Length
A2
A1
A0
No
0
Normal
0
4
0
1
0
Yes
1
Test
1
8
0
1
1
A12
Burst Type
A3
( Normal )
0
Sequential
0
Slow Exit ( low power )
1
Interleave
1
Fast Exit
BA1
A4
CAS Latency
Active Power-Down
Write Recovery
A5
A11
A10
A9
Reserved
0
0
0
2
0
0
3
0
4
5
A6
A5
A4
Reserved
0
0
0
1
Reserved
0
0
1
1
0
Reserved
0
1
0
0
1
1
3
0
1
1
1
0
0
4
1
0
0
6
1
0
1
5
1
0
1
Reserved
1
1
0
Reserved
1
1
0
Reserved
1
1
1
Reserved
1
1
1
BA0
MRS Mode
0
0
Mode Register (MRS)
0
1
Extended Mode Register / EMRS(1)
1
0
EMRS(2) * Reserved
1
1
EMRS(3) * Reserved
Feb. 2009
CAS Latency
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EM44CM1688LBA
Burst Type (A3)
Burst Length
4
8
A3
A2
A1
A0
Sequential Addressing
Interleave Addressing
X
X
0
0
0123
0123
X
X
0
1
1230
1032
X
X
1
0
2301
2301
X
X
1
1
3012
3210
X
0
0
0
01234567
01234567
X
0
0
1
12345670
10325476
X
0
1
0
23456701
23016745
X
0
1
1
34567012
32107654
X
1
0
0
45670123
45670123
X
1
0
1
56701234
54761032
X
1
1
0
67012345
67452301
X
1
1
1
70123456
* Page length is a function of I/O organization and column addressing
76543210
Write Recovery
WR (Write Recovery) is for Writes with Auto-Precharge only and defines the time
when the device starts pre-charge internally. WR must be programmed to match the minimum requirement
for the analogue tWR timing.
Power-Down Mode
Active power-down (PD) mode is defined by bit A12. PD mode allows the user to determine the active
power-down mode, which determines performance vs. power savings. PD mode bit A12 does not apply to
precharge power-down mode. When bit A12 = 0, standard Active Power-down mode or ‘fast-exit’ active
power-down mode is enabled. The tXARD parameter is used for ‘fast-exit’ active power-down exit timing.
The DLL is expected to be enabled and running during this mode.
When bit M12 = 1, a lower power active power-down mode or ‘slow-exit’ active power-down mode is
enabled. The tXARDS parameter is used for ‘slow-exit’ active power-down exit timing. The DLL can be
enabled, but ‘frozen’ during active power-down mode since the exit-to-READ command timing is relaxed.
The power difference expected between PD ‘normal’ and PD ‘low-power’ mode is defined in the IDD table.
Feb. 2009
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EM44CM1688LBA
Address input for Extended Mode Register Set ( EMRS(1) )
The EMRS (1) is written by asserting low on /CS, /RAS, /CAS, /WE,BA1 and high on BA0 ( The DDR2
should be in all bank pre-charge with CKE already prior to writing into the extended mode register. )
The extended mode register EMRS(1) stores the data for enabling or disabling the DLL, output driver
strength, additive latency,OCD program, ODT, DQS and output buffers disable, RQDS and RDQS enable.
The default value of the extended mode register EMRS(1) is not defined, therefore the extended mode
register must be written after power-up for proper operation.The mode register set command cycle time
(tMRD) must be satisfied to complete the write operation to the EMRS(1). Mode register contents can be
changed using the same command and clock cycle requirements during normal operation when all banks
are in pre-charge state.
BA1
BA0
A12
A11
0
1
Q off
RDQS /DQS
Q off
A10
0
A8
A7
A6
OCD Program
/ DQS
A12
Disable
A9
A5
Rtt
A3
AL
A10
Rtt
0
Disable
Enable
A4
A6
0
0
Disable
1
150Ω
1
0
50Ω
1
1
Disable
0
Enable
1
OCD
onlyX8
Operation
Output Driver
Impedence Control
A1
Normal (100%)
0
Weak ( 60%)
1
A9
A8
A7
Additive Latency
A5
A4
A3
OCD calibration mode exit
0
0
0
0
0
0
0
Drive (1)
0
0
1
1
0
0
1
Drive (0)
0
1
0
2
0
1
0
1
0
0
3
0
1
1
1
1
1
4
1
0
0
5
1
0
1
Reserved
1
1
0
Reserved
1
1
1
Adjust mode
(Note 1)
OCD Calibration default
BA1
DLL
0
Output
I/O
D.I.C
A0
buffers
A11
Rtt
Enable
1
RDQS,
/RQDS
A0
DLL Rest
0
1
Disable
A1
A2
75Ω
1
Enable
A2
(Note 2)
BA0
MRS Mode
0
0
Mode Register (MRS)
0
1
Extended Mode Register / EMRS(1)
1
0
EMRS(2) * Reserved
1
1
EMRS(3) * Reserved
Feb. 2009
Note 1: When adjust mode is issued, AL from
previously set value must be applied.
Note 2: After setting to default, OCD mode needs
to be exited by setting A9 ~A7 to 000.
Refer to the chapter Off-Chip Driver (OCD)
Impedance Adjustment for detailed information.
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EM44CM1688LBA
Output Drive Strength
The output drive strength is defined by bit A1. Normal drive strength outputs are specified to be SSTL_18.
Programming bit A1 = 0 selects normal (100 %) drive strength for all outputs.
Programming bit A1 = 1 will reduce all outputs to approximately 60 % of the SSTL_18 drive strength.
This option is intended for the support of the lighter load and/or point-to-point environments.
Single-ended and Differential Data Strobe Signals
EMRS
A11
(RDQS Enable)
Stobe Function Matrix
A10
(/DQS Enable)
signals
RDQS
DM
/RDQS
DQS
/DQS
0 ( Disable)
0 ( Enable)
DM
Hi -Z
DQS
/DQS
differential DQS signals
0 ( Disable)
1 ( Disable)
DM
Hi -Z
DQS
Hi -Z
single-ended DQS signals
1 ( Enable)
0 ( Enable)
RDQS
/RDQS
DQS
/DQS
differential DQS signals (for X8)
1 ( Disable)
RDQS
Hi -Z
DQS
Hi -Z
single-ended DQS signals (for X8)
only for X8
1 ( Enable)
only for X8
Output Disable ( Qoff )
Under normal operation, the DRAM outputs are enabled during Read operation for driving data (Qoff bit in
the EMRS(1) is set to (0). When the Qoff bit is set to 1, the DRAM outputs will be disabled. Disabling the
DRAM outputs allows users to measure IDD currents during Read operations, without including the output
buffer current.
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EM44CM1688LBA
Address input for Extended Mode Register Set ( EMRS(2) ) * Reserved
BA1
BA0
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
1
0
0
0
0
0
0
SRF
0
0
0
0
High Temperature Self-Refresh Rate Enable
A7
Disable
0
Enable** (85C Tcase 95C)
1
Partial Array Self Refresh
BA1
A2
A1
A0
PASR
A2
A1
A0
Full array
0
0
0
Half Array (BA[1:0]=00&01)
0
0
1
Quarter Array (BA[1:0]=00)
0
1
0
Not defined
0
1
1
3/4 array(BA[1:0]=01,10,&11)
1
0
0
Half array (BA[1:0]=10&11)
1
0
1
Quarter array (BA[1:0]=11)
1
1
0
Not defined
1
1
1
BA0
MRS Mode
0
0
Mode Register (MRS)
0
1
Extended Mode Register / EMRS(1)
1
0
EMRS(2) * Reserved
1
1
EMRS(3) * Reserved
Address input for Extended Mode Register Set ( EMRS(3) ) * Reserved
BA1
BA0
A12
A11
A10
A9
A8
A7
A6
A5
A4
A3
A2
A1
A0
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
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EM44CM1688LBA
On-Die Termination (ODT)
ODT (On-Die Termination) is a new feature on DDR2 components that allows a DRAM to turn on/off
termination resistance for each UDQ, LDQ, UDQS, UDQS, LDQS, LDQS, UDM and LDM signal via the ODT
control pin for x16 configuration, where UDQS and LDQS are terminated only when enabled in the EMRS(1)
by address bit A10 = 0.
The ODT feature is designed to improve signal integrity of the memory channel by allowing the DRAM
controller to independently turn on/off termination resistance for any or all DRAM devices.
The ODT function can be used for all active and standby modes. ODT is turned off and not supported in SelfRefresh mode.
ODT Function
Switch sw1 or sw2 is enabled by the ODT pin. Selection between sw1 or sw2 is determined by “Rtt
(nominal)” in EMRS(1) address bits A6 & A2. Target Rtt = 0.5 * Rval1 or 0.5 * Rval2.
The ODT pin will be ignored if the EMRS(1) is programmed to disable ODT.
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Off-Chip Driver (OCD) Impedance Adjustment
DR2 SDRAM supports driver calibration feature and the flow chart below is an example of the sequence.
Every calibration mode command should be followed by “OCD calibration mode exit” before any other
command being issued. MRS should be set before entering OCD impedance adjustment and ODT (On Die
Termination) should be carefully controlled depending on system environment.
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OCD impedance adjust
To adjust output driver impedance, controllers must issue the ADJUST EMRS(1) command along with a 4 bit
burst code to DDR2 SDRAM as in the following table. For this operation, Burst Length has to be set to BL = 4
via MRS command before activating OCD and controllers must drive the burst code to all DQs at the same
time. DT0 is the table means all DQ bits at bit time 0, DT1 at bit time 1, and so forth. The driver output
impedance is adjusted for all DDR2 SDRAM DQs simultaneously and after OCD calibration, all DQs of a
given DDR2 SDRAM will be adjusted to the same driver strength setting. The maximum step count for
adjustment can be up to 16 and when the limit is reached, further increment or decrement code has no
effect. The default setting may be any step within the maximum step count range. When Adjust mode
command is issued, AL from previously set value must be applied.
Off-Chip-Driver Adjust Program
4 bit burst code inputs to all DQs
Operation
DT0
DT1
DT2
DT3
Pull-up driver strength
Pull-down driver strength
0
0
0
0
NOP (no operation)
NOP (no operation)
0
0
0
1
Increase by 1 step
NOP
0
0
1
0
Decrease by 1 step
NOP
0
1
0
0
NOP
Increase by 1 step
1
0
0
0
NOP
Decrease by 1 step
0
1
0
1
Increase by 1 step
Increase by 1 step
0
1
1
0
Decrease by 1 step
Increase by 1 step
1
0
0
1
Increase by 1 step
Decrease by 1 step
1
0
1
0
Decrease by 1 step
Decrease by 1 step
Reserved
Reserved
Other Combinations
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Package Description
( BGA-84 balls Package)
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