IS43/46DR81280C
IS43/46DR16640C
128Mx8, 64Mx16 DDR2 DRAM
FEATURES
DECEMBER 2017
DESCRIPTION
• Vdd = 1.8V ±0.1V, Vddq = 1.8V ±0.1V
• JEDEC standard 1.8V I/O (SSTL_18-compatible)
• Double data rate interface: two data transfers
per clock cycle
• Differential data strobe (DQS, DQS)
• 4-bit prefetch architecture
• On chip DLL to align DQ and DQS transitions
with CK
• 8 internal banks for concurrent operation
• Programmable CAS latency (CL) 3, 4, 5, 6 and 7
supported
• Posted CAS and programmable additive latency
(AL) 0, 1, 2, 3, 4, 5 and 6 supported
• WRITE latency = READ latency - 1 tCK
• Programmable burst lengths: 4 or 8
• Adjustable data-output drive strength, full and
reduced strength options
• On-die termination (ODT)
ISSI's 1Gb DDR2 SDRAM uses a double-data-rate
architecture to achieve high-speed operation. The
double-data rate architecture is essentially a 4n-prefetch
architecture, with an interface designed to transfer two
data words per clock cycle at the I/O balls.
OPTIONS
KEY TIMING PARAMETERS
• Configuration(s):
128Mx8 (16Mx8x8 banks): IS43/46DR81280C
64Mx16 (8Mx16x8 banks): IS43/46DR16640C
• Package:
x8: 60-ball BGA (8mm x 10.5mm)
x16: 84-ball WBGA (8mm x 12.5mm)
• Timing – Cycle time
2.5ns @CL=5 DDR2-800D
2.5ns @CL=6 DDR2-800E
3.0ns @CL=5 DDR2-667D
3.75ns @CL=4 DDR2-533C
5ns @CL=3 DDR2-400B
• Temperature Range:
ADDRESS TABLE
Parameter
128M x 8
64M x 16
Configuration
16M x 8 x 8
banks
8M x 16 x 8
banks
Refresh Count
8K/64ms
8K/64ms
Row Addressing
16K (A0-A13) 8K (A0-A12)
Column
Addressing
1K (A0-A9)
1K (A0-A9)
Bank Addressing
BA0 - BA2
BA0 - BA2
Precharge
Addressing
A10
A10
Speed Grade
-25D
-3D
tRCD
12.5
15
tRP
12.5
15
tRC
55
55
tRAS
40
40
tCK @CL=3
5
5
tCK @CL=4
3.75
3.75
tCK @CL=5
2.5
3
tCK @CL=6
2.5
—
Commercial (0°C ≤ Tc ≤ 85°C)
Industrial (-40°C ≤ Tc ≤ 95°C; -40°C ≤ Ta ≤ 85°C)
Automotive, A1 (-40°C ≤ Tc ≤ 95°C; -40°C ≤ Ta ≤ 85°C)
Automotive, A2 (-40°C ≤ Tc; Ta ≤ 105°C)
Tc = Case Temp, Ta = Ambient Temp
Copyright © 2017 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without
notice. ISSI assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest
version of this device specification before relying on any published information and before placing orders for products.
Integrated Silicon Solution, Inc. does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications
unless Integrated Silicon Solution, Inc. receives written assurance to its satisfaction, that:
a.) the risk of injury or damage has been minimized;
b.) the user assume all such risks; and
c.) potential liability of Integrated Silicon Solution, Inc is adequately protected under the circumstances
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Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
General Description
Read and write accesses to the DDR2 SDRAM are burst oriented; accesses start at a selected location and continue
for a burst length of four or eight in a programmed sequence. Accesses begin with the registration of an Active
command, which is then followed by a Read or Write command. The address bits registered coincident with the active
command are used to select the bank and row to be accessed (BA0-BA2 select the bank; A0-A12(x16) or A0-A13(x8)
select the row). The address bits registered coincident with the Read or Write command are used to select the starting
column location A0-A9 for the burst access and to determine if the auto precharge A10 command is to be issued.
Prior to normal operation, the DDR2 SDRAM must be initialized. The following sections provide detailed information
covering device initialization, register definition, command descriptions and device operation.
Functional Block Diagram
DMa - DMb
RDQS, RDQS
Notes:
1. An:n = no. of address pins - 1
2. DQm: m = no. of data pins - 1
3. For x8 devices:
DMa - DMb = DM; DQSa - DQSb = DQS; DQSa - DQSb = DQS; RDQS, RDQS available only for x8
4. For x16 devices:
DMa - DMb = UDM, LDM; DQSa - DQSb = UDQS, LDQS; DQSa - DQSb = UDQS, LDQS
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IS43/46DR81280C, IS43/46DR16640C
pin description table
Symbol
Type
Function
Input
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).
CKE
Input
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. After VREF has become
stable during the power on and initialization sequence, it must be maintained for
proper operation of the CKE receiver. For proper self-refresh entry and exit, VREF
must be maintained to this input. 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.
CS
Input
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.
ODT
Input
On Die Termination: ODT (registered HIGH) enables termination resistance internal
to the DDR2 SDRAM. When enabled, ODT is applied to each DQ, DQS, DQS, DM
signals. The ODT pin will be ignored if the EMR(1) is programmed to disable ODT.
RAS, CAS, WE
Input
CK, CK
DM (x8) or
UDM, LDM (x16)
BA0 - BA2
A0 - A13
Command Inputs: RAS, CAS and WE (along with CS) define the command being
entered.
Input
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. For x8, the function of DM is enabled by EMRS
command to EMR(1) [A11].
Input
Bank Address Inputs: BA0 - BA2 define to which bank an Active, Read, Write or
Precharge command is being applied. Bank address also determines if the mode
register or one of the extended mode registers is to be accessed during a MRS or
EMRS command cycle.
Input
Address Inputs: Provide the row address for Active commands and the column
address and Auto Precharge bit for Read/Write commands to select one location
out of the memory array in the respective bank. 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, the bank is selected by BA0 BA2. The address inputs also provide the op-code during MRS or EMRS commands.
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Rev. B
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IS43/46DR81280C, IS43/46DR16640C
Symbol
Type
Function
DQ0-7 x8
DQ0-15 x16
Input/
Output
Data Input/Output: Bi-directional data bus.
DQS, (DQS)
RDQS, (RDQS) x8
UDQS, (UDQS),
LDQS, (LDQS) x16
Data Strobe: output with read data, input with write data. Edge-aligned with read data,
centered in write data. The data strobes DQS(n) may be used in single ended mode
or paired with optional complementary signals DQS(n) to provide differential pair
signaling to the system during both reads and writes. A control bit at EMR(1)[A10]
enables or disables all complementary data strobe signals.
Input/
Output
x8
DQS corresponds to the data on DQ0-DQ7
RDQS corresponds to the Read data on DQ0-DQ7, and is enabled by EMRS
command to EMR(1) [A11].
x16
LDQS corresponds to the data on DQ0-DQ7
UDQS corresponds to the data on DQ8-DQ15
NC
No Connect: No internal electrical connection is present.
VDDQ
Supply
DQ Power Supply: 1.8 V +/- 0.1 V
VSSQ
Supply
DQ Ground
VDDL
Supply
DLL Power Supply: 1.8 V +/- 0.1 V
VSSDL
Supply
DLL Ground
VDD
Supply
Power Supply: 1.8 V +/- 0.1 V
VSS
Supply
Ground
VREF
Supply
Reference voltage
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Rev. B
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IS43/46DR81280C, IS43/46DR16640C
PIN CONFIGURATION
package code: B 60 bALL fbga (Top View) (8.00 mm x 10.5 mm Body, 0.8 mm Ball Pitch)
1 2 3 4 5 6 7 8 9
A
B
C
D
E
F
G
H
J
K
L
VDD RDQS VSS
VSSQ DQS VDDQ
DQ6
DQS
VSSQ DM/RDQS
VDDQ DQ1 VDDQ
DQ4
VSSQ DQ7
VDDQ DQ0 VDDQ
VSSQ DQ3
DQ2
VSSQ DQ5
VDDL VREF
VSS
VSSDL
CK
VDD
CKE
WE
RAS
CK
ODT
BA0
BA1
CAS
CS
A10
A1
A2
A0
A3
A5
A6
A4
A7
A9
A11
A8
A12
NC
NC
A13
BA2
VSS
VDD
VDD
VSS
Not populated
Pin name
Function
Pin name
Function
A0 to A13
Address inputs
ODT
ODT control
BA0 to BA2
Bank select
VDD
Supply voltage for internal circuit
DQ0 to DQ7
Data input/output
VSS
Ground for internal circuit
DQS, /DQS
Differential data strobe
VDDQ
Supply voltage for DQ circuit
/CS
Chip select
VSSQ
Ground for DQ circuit
/RAS, /CAS, /WE Command input
VREF
Input reference voltage
CKE
Clock enable
VDDL
Supply voltage for DLL circuit
CK, /CK
Differential clock input
VSSDL
Ground for DLL circuit
DM
Write data mask
NC
No connection
RDQS, /RDQS
Differential Redundant Data Strobe
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Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
PIN CONFIGURATION
package code: B 84 bALL fbga (Top View) (8.00 mm x 12.50 mm Body, 0.8 mm Ball Pitch)
1 2 3 4 5 6 7 8 9
A
B
C
D
E
F
G
H
J
K
L
M
N
P
R
VDD
VSS
VSSQ UDQS VDDQ
DQ14 VSSQ UDM
UDQS VSSQ DQ15
VDDQ DQ9 VDDQ
VDDQ DQ8 VDDQ
DQ12 VSSQ DQ11
DQ10 VSSQ DQ13
VDD
VSSQ LDQS VDDQ
DQ6
NC
NC
VSS
VSSQ LDM
LDQS VSSQ DQ7
VDDQ DQ1 VDDQ
DQ4
VDDQ DQ0 VDDQ
VSSQ DQ3
DQ2
VSSQ DQ5
VDDL VREF
VSS
VSSDL
CK
VDD
CKE
WE
RAS
CK
ODT
BA0
BA1
CAS
CS
A2
A0
BA2
A10/AP A1
VSS
VDD
A3
A5
A6
A4
A7
A9
A11
A8
A12
NC
NC
NC
VDD
VSS
Not populated
Pin name
Function
Pin name
Function
A0 to A12
Address inputs
ODT
ODT control
BA0 to BA2
Bank select
VDD
Supply voltage for internal circuit
DQ0 to DQ15
Data input/output
VSS
Ground for internal circuit
LDQS, UDQS
Differential data strobe
VDDQ
Supply voltage for DQ circuit
Chip select
VSSQ
Ground for DQ circuit
/RAS, /CAS, /WE Command input
VREF
Input reference voltage
CKE
Clock enable
VDDL
Supply voltage for DLL circuit
CK, /CK
Differential clock input
VSSDL
Ground for DLL circuit
LDM to UDM
Write data mask
NC
No connection
/LDQS, /UDQS
/CS
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Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
electrical specifications
Absolute Maximum DC Ratings
Symbol
Parameter
Rating
Units
Notes
Vdd
Voltage on VDD pin relative to Vss
- 1.0~ 2.3
V
1,3
Vddq
Voltage on VDDQ pin relative to Vss
- 0.5~ 2.3
V
1,3
Vddl
Voltage on VDDL pin relative to Vss
- 0.5~ 2.3
V
1,3
Vin, Vout
Voltage on any pin relative to Vss
- 0.5~ 2.3
V
1,4
Tstg
Storage Temperature
-55 to +150
°C
1, 2
Ii
Input Leakage Current
- 5~ 5
uA
4
Ioz
Output Leakage Current
- 5~ 5
uA
4
Ivref
Vref Leakage Current
- 2~ 2
uA
3
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. Storage Temperature is the case surface temperature on the center/top side of the DRAM. For the measurement conditions, please refer to
JESD51-2 standard.
3. VDD and VDDQ must be within 300mV of each other at all times; and VREF must be not greater than 0.6 x VDDQ. When VDD and VDDQ and
VDDL are less than 500 mV, Vref may be equal to or less than 300 mV.
4. Voltage on any input or I/O may not exceed voltage on VDDQ.
AC & DC Recommended Operating Conditions
Recommended DC Operating Conditions (SSTL-1.8)
Symbol
Parameter
Rating
Units Notes
Min.
Typ.
Max.
VDD
Supply Voltage
1.7
1.8
1.9
V
1
VDDL
Supply Voltage for DLL
1.7
1.8
1.9
V
5
VDDQ
Supply Voltage for Output
1.7
1.8
1.9
V
1, 5
VREF
Input Reference Voltage
0.49 x VDDQ
0.50 x VDDQ
0.51 x VDDQ
V
2. 3
VTT
Termination Voltage
VREF - 0.04
VREF
VREF + 0.04
V
4
Notes:
1. There is no specific device VDD supply voltage requirement for SSTL_18 compliance. However under all conditions VDDQ must be less than
or equal to VDD.
2. The value of VREF may be selected by the user to provide optimum noise margin in the system. Typically the value of VREF is expected to be
about 0.5 x VDDQ of the transmitting device and VREF is expected to track variations in VDDQ.
3. Peak to peak ac noise on VREF may not exceed +/-2 % VREF(dc).
4. VTT of transmitting device must track VREF of receiving device.
5. VDDQ tracks with VDD, VDDL tracks with VDD. AC parameters are measured with VDD, VDDQ and VDDL tied together
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Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
Operating Temperature Condition
Symbol
Parameter
Rating(1,2,3)
TOPER
Commercial Temperature
Units
Tc = 0 to +85
o
C
Industrial Temperature,
Tc = -40 to +95
o
C
Automotive Temperature (A1)
Ta = -40 to +85
o
C
Automotive Temperature (A2)
Tc = -40 to +105
o
C
Ta = -40 to +105
o
C
Notes:
1. Tc = Operating case temperature at center of package
2. Ta = Operating ambient temperature immediately above package center.
3. Both temperature specifications must be met.
Thermal Resistance:
Package
Substrate
Theta-ja
(Airflow = 0m/s)
Theta-ja
(Airflow = 1m/s)
Theta-ja
(Airflow = 2m/s)
Theta-jc
Units
60-ball BGA
4-layer
55.1
34.7
32.2
8.0
C/W
84-ball BGA
4-layer
53.4
33.6
31.3
7.9
C/W
ODT DC Electrical Characteristics
PARAMETER/CONDITION
SYMBOL
MIN
NOM
MAX
UNITS NOTES
Rtt effective impedance value for EMR(1)[A6,A2]=0,1; 75 Ω
Rtt1(eff)
60
75
90
Ω
1
Rtt effective impedance value for EMR(1)[A6,A2]=1,0; 150 Ω Rtt2(eff)
120
150
180
Ω
1
Rtt effective impedance value for EMR(1)[A6,A2]=1,1; 50 Ω
Rtt3(eff)
40
50
60
Ω
1
Deviation of VM with respect to VDDQ/2
ΔVM
-6
+6
%
1
Notes:
1. Test condition for Rtt measurements
Measurement Definition for Rtt(eff): Apply VIH (ac) and VIL (ac) to test pin separately, then measure current I(VIH (ac)) and I( VIL
(ac)) respectively. VIH (ac), VIL (ac), and VDDQ values defined in SSTL_18
Rtt (eff)
Vih (ac) - Vil (ac)
I(Vih (ac)) - I(Vil (ac))
Measurement Definition for VM: Measure voltage (VM) at test pin (midpoint) with no load.
ΔVM = [(2 x VM / VDDQ) - 1] x 100%
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IS43/46DR81280C, IS43/46DR16640C
Input DC logic level
Symbol
Parameter
Min.
Max.
Units
VIH(dc)
dc input logic HIGH
VREF + 0.125
VDDQ + 0.3
V
VIL(dc)
dc input logic LOW
- 0.3
VREF - 0.125
V
Notes
Input AC logic level
Symbol Parameter
DDR2-400, DDR2-533
DDR2-667, DDR2-800
Min.
Max.
Min.
Max
VIH (ac) ac input logic HIGH
VREF + 0.250
VDDQ + Vpeak
VREF + 0.200
VDDQ + Vpeak
V
1
VIL (ac)
VSSQ - Vpeak
VREF - 0.250
VSSQ - Vpeak
VREF - 0.200
V
1
ac input logic LOW
Units Notes
Notes:
1. Refer to Overshoot/undershoot specifications for Vpeak value: maximum peak amplitude allowed for overshoot and undershoot.
AC Input Test Conditions
Symbol
Condition
VREF
Input reference voltage
Value
Units
0.5 x VDDQ
V
VSWING(MAX)
SLEW
Notes
1
Input signal maximum peak to peak swing
1.0
V
1
Input signal minimum slew rate
1.0
V/ns
2, 3
Notes:
1. Input waveform timing is referenced to the input signal crossing through the VIH/IL(AC) level applied to the device under test.
2. The input signal minimum slew rate is to be maintained over the range from VREF to VIH(ac) min for rising edges and the range from VREF to
VIL(ac) max for falling edges as shown in the below figure.
3. AC timings are referenced with input waveforms switching from VIL(ac) to VIH(ac) on the positive transitions and VIH(ac) to VIL(ac) on the
negative transitions.
AC input test signal waveform
VDDQ
VIH(ac) min
VIH(dc) min
VSWING(MAX)
VREF
VIL(dc) max
VIL(ac) max
DTF
Falling Slew =
DTR
VREF - VIL(ac) max
DTF
Rising Slew =
VSS
VIH(ac) min - VREF
DTR
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IS43/46DR81280C, IS43/46DR16640C
Differential input AC Logic Level
Symbol
Parameter
Min.
Max.
Units
Notes
VID (ac)
ac differential input voltage
0.5
VDDQ
V
1,3
VIX (ac)
ac differential crosspoint voltage
0.5 x VDDQ - 0.175
0.5 x VDDQ + 0.175
V
2
Notes:
1. VID(AC) specifies the input differential voltage |VTR -VCP | required for switching, where VTR is the true input signal (such as CK, DQS and
VCP is the complementary input signal (such as CK or DQS). The minimum value is equal to VIH(AC) - VIL(AC).
2. The typical value of VIX(AC) is expected to be about 0.5 x VDDQ of the transmitting device and VIX(AC) is expected to track variations in
VDDQ. VIX(AC) indicates the voltage at which differential input signals must cross.
3. Refer to Overshoot/undershoot specifications for Vpeak value: maximum peak amplitude allowed for overshoot and undershoot.
Differential signal levels
VDDQ
VTR
Crossing point
VID
VIX or VOX
VCP
VSSQ
Differential AC Output Parameters
Symbol
Parameter
VOX (ac) ac differential crosspoint voltage
Min.
Max.
0.5 x VDDQ - 0.125
0.5 x VDDQ + 0.125
Units Notes
V
1
Note:
1. The typical value of VOX(AC) is expected to be about 0.5 x VDDQ of the transmitting device and VOX(AC) is expected to track variations in
VDDQ. VOX(AC) indicates the voltage at which differential output signals must cross.
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IS43/46DR81280C, IS43/46DR16640C
Overshoot/Undershoot Specification
AC overshoot/undershoot specification for Address and Control pins
Parameter
Specification
Maximum peak amplitude allowed for overshoot area
Maximum peak amplitude allowed for undershoot area
DDR2-400
DDR2-533
DDR2-667
DDR2-800
0.5V
0.5V
0.5V
0.5V
0.5V
0.5V
0.5V
0.5V
Maximum overshoot area above VDD (see figure below)
1.33 V-ns
1.0 V-ns
0.8 V-ns
0.66 V-ns
Maximum undershoot area below VSS (see figure below)
1.33 V-ns
1.0 V-ns
0.8 V-ns
0.66 V-ns
Maximum Amplitude
Overshoot Area
VDD
Volts VSS
(V)
Maximum Amplitude
Undershoot Area
Time (ns)
AC overshoot and undershoot definition for address and control pins
AC overshoot/undershoot specification for Clock, Data, Strobe, and Mask pins:
DQ, (U/L/R) DQS, (U/L/R) DQS, DM, CK, CK
Parameter
Specification
DDR2-400
DDR2-533
DDR2-667
DDR2-800
Maximum peak amplitude allowed for overshoot area
0.5V
0.5V
0.5V
0.5V
Maximum peak amplitude allowed for undershoot area
0.5V
0.5V
0.5V
0.5V
Maximum overshoot area above VDDQ (See Figure below)
0.38 V-ns
0.28 V-ns
0.23 V-ns
0.23 V-ns
Maximum undershoot area below VSSQ (See Figure below)
0.38 V-ns
0.28 V-ns
0.23 V-ns
0.23 V-ns
Maximum Amplitude
Overshoot Area
VDDQ
Volts VSSQ
(V)
Maximum Amplitude
Undershoot Area
Time (ns)
AC overshoot and undershoot definition for clock, data, strobe, and mask pins
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IS43/46DR81280C, IS43/46DR16640C
Output Buffer Characteristics
Output AC Test Conditions
Symbol
Parameter
SSTL_18
Units
VOTR
Output Timing Measurement Reference Level
0.5 x VDDQ
V
Notes
1
Output DC Current Drive
Symbol
Parameter
IOH(dc)
Output Minimum Source DC Current
IOL(dc)
Output Minimum Sink DC Current
SSTL_18
Units
Notes
- 13.4
mA
1, 3, 4
13.4
mA
2, 3, 4
Notes:
1. VDDQ = 1.7 V; VOUT = 1420 mV. (VOUT - VDDQ)/IOH must be less than 21 Ω for values of VOUT between VDDQ and VDDQ - 280 mV.
2. VDDQ = 1.7 V; VOUT = 280 mV. VOUT/IOL must be less than 21 Ω for values of VOUT between 0 V and 280 mV.
3. The dc value of VREF applied to the receiving device is set to VTT
4. The values of IOH(dc) and IOL(dc) are based on the conditions given in Notes 1 and 2. They are used to test device drive current capability to
ensure VIH min plus a noise margin and VIL max minus a noise margin are delivered to an SSTL_18 receiver. The actual current values are
derived by shifting the desired driver operating point (see Section 3.3 of JESD8-15A) along a 21 Ω load line to define a convenient driver current for measurement.
OCD Default Characteristics
Description
Parameter
Output impedance
Min
Nom
Max
See full strength default
driver characteristics
Unit
Notes
Ω
1
Output impedance step size
for OCD calibration
0
1.5
Ω
6
Pull-up and pull-down
mismatch
0
4
Ω
1,2,3
1.5
5
V/ns
Output slew rate
Sout
1,4,5,7,8,9
Notes:
1. Absolute Specifications (TOPER; VDD = +1.8V ±0.1V, VDDQ = +1.8V ±0.1V). DRAM I/O specifications for timing, voltage, and slew rate are no
longer applicable if OCD is changed from default settings.
2. Impedance measurement condition for output source dc current: VDDQ = 1.7 V; VOUT = 1420 mV; (VOUTVDDQ)/IOH must be less than 23.4
Ω for values of VOUT between VDDQ and VDDQ - 280 mV. Impedance measurement condition for output sink dc current: VDDQ = 1.7 V;
VOUT = 280 mV; VOUT/IOL must be less than 23.4 Ω for values of VOUT between 0 V and 280 mV.
3. Mismatch is absolute value between pull-up and pull-down, both are measured at same temperature and voltage.
4. Slew rate measured from VIL(ac) to VIH(ac).
5. The absolute value of the slew rate as measured from DC to DC is equal to or greater than the slew rate as measured from AC to AC. This is
guaranteed by design and characterization.
6. This represents the step size when the OCD is near 18 Ω at nominal conditions across all process corners/variations and represents only the
DRAM uncertainty. A 0 Ω value (no calibration) can only be achieved if the OCD impedance is 18 Ω +/-0.75 Ω under nominal conditions.
7. DRAM output slew rate specification applies to 400 MT/s, 533 MT/s & 667 MT/s speed bins.
8. Timing skew due to DRAM output slew rate mis-match between DQS / DQS and associated DQ’s is included in tDQSQ and tQHS specification.
9. DDR2 SDRAM output slew rate test load is defined in General Note 3 of the AC Timing specification Table.
12
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IS43/46DR81280C, IS43/46DR16640C
IDD Specifications & Test Conditions
Symbol Conditions
IDD0
Operating one bank active-precharge current;
tCK = tCK(IDD), tRC = tRC(IDD), tRAS = tRASmin(IDD);
CKE is HIGH, CS is HIGH between valid commands;
-25D/-25E
-3D
-37C
-5B
Units
DDR2800D/800E
DDR2667D
DDR2533C
DDR2400B
100
90
85
80
mA
115
105
95
85
mA
25
23
20
20
mA
35
30
25
23
mA
35
30
28
25
mA
40
35
35
35
mA
30
28
28
28
80
70
65
60
mA
200
180
170
160
mA
Address bus inputs are SWITCHING; Data bus inputs are
SWITCHING
IDD1
Operating one bank active-read-precharge current;
IOUT = 0mA; BL = 4, CL = CL(IDD), AL = 0;
tCK = tCK(IDD), tRC = tRC (IDD), tRAS = tRASmin(IDD), tRCD =
tRCD(IDD);
CKE is HIGH, CS is HIGH between valid commands;
Address bus inputs are SWITCHING; Data pattern is same as
IDD4W
IDD2P
Precharge power-down current; All banks idle;
tCK = tCK(IDD); CKE is LOW;
Other control and address bus inputs are STABLE;
Data bus inputs are FLOATING
IDD2Q Precharge quiet standby current; All banks idle;
tCK = tCK(IDD);
CKE is HIGH, CS is HIGH; Other control and address bus inputs
are STABLE;
Data bus inputs are FLOATING
IDD2N
Precharge standby current; All banks idle;
tCK = tCK(IDD);
CKE is HIGH, CS is HIGH; Other control and address bus inputs
are SWITCHING;
Data bus inputs are SWITCHING
Active power-down current; All banks open;
IDD3P tCK = tCK(IDD); CKE is LOW;
Other control and address bus inputs are STABLE;
Data bus inputs are FLOATING
Power Down
Fast Exit
Power Down
Slow Exit
IDD3N Active standby current; All banks open;
tCK = tCK(IDD), tRAS = tRASmax(IDD), tRP = tRP(IDD);
CKE is HIGH, CS is HIGH between valid commands;
Other control and address bus inputs are SWITCHING; Data bus
inputs are SWITCHING
IDD4W Operating burst write current; All banks open, Continuous burst
writes;
BL = 4, CL = CL(IDD), AL = 0; tCK = tCK(IDD), tRAS =
tRASmax(IDD), tRP = tRP(IDD);
CKE is HIGH, CS is HIGH between valid commands;
Address bus inputs are SWITCHING; Data bus inputs are
SWITCHING
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Rev. B
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IS43/46DR81280C, IS43/46DR16640C
IDD Specifications & Test Conditions (continued)
Symbol Conditions
-25D/-25E
-3D
-37C
-5B
Units
DDR2800D/800E
DDR2667D
DDR2533C
DDR2400B
180
160
150
140
mA
180
170
160
150
mA
10
10
10
10
mA
260
240
220
200
mA
IDD4R Operating burst read current; All banks open, Continuous burst
reads,
IOUT = 0 mA; BL = 4, CL = CL(IDD), AL = 0; tCK = tCK(IDD), tRAS
= tRASmax(IDD), tRP = tRP(IDD);
CKE is HIGH, CS is HIGH between valid commands;
Address bus inputs are SWITCHING; Data pattern is same as
IDD4W
IDD5B Burst refresh current;
tCK = tCK(IDD); Refresh command at every tRFC(IDD) interval;
CKE is HIGH, CS is HIGH between valid commands; Other control
and address bus inputs are SWITCHING;
Data bus inputs are SWITCHING
IDD6
Self refresh current;
CK and CK at 0 V; CKE ≤ 0.2 V;
Other control and address bus inputs are FLOATING;
Data bus inputs are FLOATING
IDD7
Operating bank interleave read current;
All bank interleaving reads, IOUT = 0mA; BL = 4, CL = CL(IDD), AL
= tRCD(IDD) - 1 x tCK(IDD);
tCK = tCK(IDD), tRC = tRC(IDD), tRRD = tRRD(IDD),
tRCD = 1 x tCK(IDD);
CKE is HIGH, CS is HIGH between valid commands; Address bus
inputs are STABLE during DESELECTs;
Data pattern is same as IDD4R
Notes:
1. IDD specifications are tested after the device is properly initialized
2. Input slew rate is specified by AC Parametric Test Condition
3. IDD parameters are specified with ODT disabled.
4. Data bus consists of DQ, DM, DQS, DQS, RDQS, RDQS, LDQS, LDQS, UDQS, and UDQS. IDD values must be met with all combinations of
EMR(1) bits 10 and 11.
5. For DDR2-667/800 testing, tCK in the Conditions should be interpreted as tCK(avg)
6. Definitions for IDD
LOW = Vin ≤ VILAC(max)
HIGH = Vin ≥ VIHAC(min)
STABLE = inputs stable at a HIGH or LOW level
FLOATING = inputs at VREF = VDDQ/2
SWITCHING = inputs changing between HIGH and LOW every other clock cycle (once per two clocks) for address and control signals, and inputs
changing between HIGH and LOW every other data transfer (once per clock) for DQ signals not including masks or strobes.
7. The -25E, -37C, and-5B device specifications are shown for reference only.
14
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IS43/46DR81280C, IS43/46DR16640C
IDD testing parameters
Speed
Bin(CL-tRCD-tRP)
DDR2-800D DDR2-667D
Units
5-5-5
5-5-5
5
5
tCK
12.5
15
ns
tRC(IDD)
55
55
ns
tRRD(IDD) x8
7.5
7.5
ns
tRRD(IDD) x16
10
10
ns
tCK(IDD)
2.5
3
ns
tRASmin(IDD)
40
40
ns
tRASmax(IDD)
70
70
ms
CL(IDD)
tRCD(IDD)
tRP(IDD)
12.5
15
ns
tRFC(IDD)
105
105
ns
Input/Output Capacitance:
Parameter
Symbol
DDR2-400
DDR2-667
DDR2-800
Units
DDR2-553
Min.
Max.
Min.
Max
Min.
Max.
1.0
2.0
1.0
2.0
1.0
2.0
pF
–
0.25
–
0.25
–
0.25
pF
1.0
2.0
1.0
2.0
1.0
1.75
pF
Input capacitance, CK and CK
CCK
Input capacitance delta, CK and CK
CDCK
Input capacitance, all other input-only pins
CI
Input capacitance delta, all other input-only
pins
CDI
–
0.25
–
0.25
–
0.25
pF
Input/output capacitance, DQ, DM, DQS,
DQS
CIO
2.5
4.0
2.5
3.5
2.5
3.5
pF
Input/output capacitance delta, DQ, DM,
DQS, DQS
CDIO
–
0.5
–
0.5
–
0.5
pF
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Rev. B
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IS43/46DR81280C, IS43/46DR16640C
Electrical Characteristics & AC Timing Specifications
Refresh parameters (TOPER; VDDQ = 1.8 V +/- 0.1 V; VDD = 1.8 V +/- 0.1 V)
Parameter
Symbol
Refresh to active/Refresh command time
Units
tRFC
127.5
ns
1
-40 C ≤ Tc < 0 C
7.8
ms
1,2
0 C ≤ Tc ≤ 85 C
7.8
ms
1
85 C < Tc ≤ 95 C
3.9
ms
1,2
95 C < Tc ≤ 105 C
3.9
ms
1,2,3
o
o
o
Average periodic refresh interval
tREFI
Notes
o
o
o
o
o
Notes:
1. If refresh timing is violated, data corruption may occur and the data must be re-written with valid data before a valid READ can be executed.
2. Specified for Industrial and Automotive grade only; not applicable for Commercial grade. Toper may not be violated.
3. Specified for Automotive grade (A2) only; not applicable for any other grade. Toper may not be violated.
Key Timing Parameters by Speed Grade
-25D
-25E
-3D
-37C
-5B
DDR2-800D
DDR2-800E
DDR2-667D
DDR2-533C
DDR2-400B
CL-tRCD-tRP
5-5-5
6-6-6
5-5-5
4-4-4
3-3-3
tRCD
12.5
15
15
15
15
tRP
12.5
15
15
15
15
tRC
55
55
55
55
55
tRAS
40
40
40
40
40
tCK(avg)@CL=3
5
5
5
5
5
tCK(avg)@CL=4
3.75
3.75
3.75
3.75
5
tCK(avg)@CL=5
2.5
3
3
–
–
tCK(avg)@CL=6
2.5
2.5
–
–
–
Speed bin (JEDEC)
Note:
Each of the -25D and -3D speed options is individually backward compatible with all the timing specifications for slower options (ie. -25D
complies with specifications for -25D, -25E, -3D, -37C, -5B). -25E, -37C, and -5B shown for reference only.
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12/6/2017
IS43/46DR81280C, IS43/46DR16640C
Timing Parameters by Speed Grade (DDR2-400 and DDR2-533)
(For information related to the entries in this table, refer to both the Guidelines and the Specific Notes following this Table.)
Parameter
Symbol
DDR2-400
DDR2-553
Min.
Max.
Min.
Max
Units Notes
Clock cycle time, CL=x
tCK
5
8
3.75
8
ns
CK HIGH pulse width
tCH
0.45
0.55
0.45
0.55
tCK
CK LOW pulse width
tCL
0.45
0.55
0.45
0.55
tCK
tDQSS
- 0.25
0.25
- 0.25
0.25
tCK
DQS falling edge to CK setup time
tDSS
0.2
–
0.2
–
tCK
DQS falling edge hold time from CK
tDSH
0.2
–
0.2
–
tCK
DQS input HIGH pulse width
tDQSH
0.35
–
0.35
–
tCK
DQS input LOW pulse width
tDQSL
0.35
–
0.35
–
tCK
Write preamble
tWPRE
0.35
–
0.35
–
tCK
Write postamble
tWPST
0.4
0.6
0.4
0.6
tCK
Address and control input setup time
tIS(base)
350
–
250
–
ps
Address and control input hold time
tIH(base)
475
–
375
–
ps
DQS latching rising transitions to associated clock
edges
Control & Address input pulse width for each input
15
10
5, 7, 9,
22
5, 7, 9,
23
tIPW
0.6
–
0.6
–
tCK
DQ and DM input setup time (differential strobe)
tDS(base)
150
–
100
–
ps
6, 7, 8,
20, 28
DQ and DM input hold time (differential strobe)
tDH(base)
275
–
225
–
ps
DQ and DM input setup time (single-ended strobe)
tDS1(base)
25
–
- 25
–
ps
DQ and DM input hold time (single-ended strobe)
tDH1(base)
25
–
- 25
–
ps
6, 7, 8,
21, 28
6, 7, 8,
25
6, 7, 8,
26
DQ and DM input pulse width for each input
tDIPW
0.35
–
0.35
–
tCK
DQ output access time from CK/CK
DQS output access time from CK/ CK
Data-out high-impedance time from CK/ CK
tAC
tDQSCK
tHZ
- 600
- 500
+ 600
+ 500
tAC max
- 500
- 450
ps
ps
DQS(DQS) low-impedance time from CK/ CK
tLZ(DQS)
tAC min
tAC max
tAC min
DQ low-impedance time from CK/ CK
tLZ(DQ)
2 x tAC
min
tAC max
2 x tAC
min
+ 500
+ 450
tAC
max
tAC
max
tAC
max
DQS-DQ skew for DQS and associated DQ signals
tDQSQ
–
350
–
300
ps
13
min (tCL,
tCH)
–
min (tCL,
tCH)
–
ps
11,12
12
–
–
ps
ps
ps
18
18
18
CK half pulse width
tHP
DQ hold skew factor
tQHS
–
450
–
400
ps
tQH
tHP tQHS
–
tHP - tQHS
–
ps
Read preamble
tRPRE
0.9
1.1
0.9
1.1
tCK
19
Read postamble
tRPST
0.4
0.6
0.4
0.6
tCK
19
DQ/DQS output hold time from DQS
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IS43/46DR81280C, IS43/46DR16640C
Timing Parameters by Speed Grade (DDR2-400 and DDR2-533) cont'd
(For information related to the entries in this table, refer to both the Guidelines and the Specific Notes following this Table.)
Parameter
Symbol
Active to active command period
tRRD
Four Activate Window
tFAW
CAS to CAS command delay
DDR2-400
DDR2-533
Units Notes
Min.
Max.
Min.
Max.
x8
7.5
–
7.5
–
x16
10
–
10
–
x8
x16
37.5
50
–
–
37.5
50
–
–
ns
ns
tCCD
2
–
2
–
tCK
Write recovery time
tWR
Auto precharge write recovery + precharge
tDAL
time
Internal write to read command delay
tWTR
15
–
15
–
ns
WR + tRP
–
WR + tRP
–
tCK
14
10
–
7.5
–
ns
24
Internal read to precharge command delay tRTP
7.5
–
7.5
–
ns
3
3
–
3
–
tCK
27
ns
4
CKE minimum pulse width (HIGH and
LOW pulse width)
tCKE
Exit self refresh to a non-read command
tXSNR
tRFC + 10
–
tRFC + 10
–
ns
Exit self refresh to a read command
tXSRD
200
–
200
–
tCK
Exit precharge power down to any nonread command
tXP
2
–
2
–
tCK
Exit active power down to read command
tXARD
2
–
2
–
tCK
1
Exit active power down to read command
(slow exit, lower power)
tXARDS
6 - AL
–
6 - AL
–
tCK
1,2
ODT turn-on delay
tAOND
2
2
2
2
tCK
16
ODT turn-on
tAON
tAC(min)
tAC(max)+1
tAC(min)
tAC (max)+1
ns
16
ODT turn-on (Power-Down mode)
tAONPD
tAC(min)+2
2 x tCK +
tAC(max)+1
tAC(min) + 2
2 x tCK +
tAC(max)+1
ns
ODT turn-off delay
tAOFD
2.5
2.5
2.5
2.5
tCK
17,
44
ODT turn-off
tAOF
tAC(min)
tAC(max) +
0.6
tAC(min)
tAC(max) + 0.6
ns
17,
44
ODT turn-off (Power-Down mode)
tAOFPD
tAC(min)+2
2.5 x tCK +
tAC(max)+1
tAC(min)+2
2.5 x tCK+
tAC(max)+1
ns
ODT to power down entry latency
tANPD
3
–
3
–
tCK
ODT power down exit latency
tAXPD
8
–
8
–
tCK
Mode register set command cycle time
tMRD
2
–
2
–
tCK
MRS command to ODT update delay
tMOD
0
12
0
12
ns
OCD drive mode output delay
tOIT
0
12
0
12
ns
Minimum time clocks remains ON after
CKE asynchronously drops LOW
tDelay
tIS+tCK+tIH
–
tIS+tCK+tIH
–
ns
18
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IS43/46DR81280C, IS43/46DR16640C
Timing Parameters by Speed Grade (DDR2-667 and DDR2-800)
(For information related to the entries in this table, refer to both the Guidelines and the Specific Notes following this Table.)
Parameter
Symbol
Average clock period
DDR2-667
DDR2-800
Units
Notes
8
ns
35,36
0.45
0.55
tCK(avg)
35,36
0.55
0.45
0.55
tCK(avg)
35,36
- 0.25
0.25
- 0.25
0.25
tCK(avg)
30
tDSS
0.2
–
0.2
–
tCK(avg)
30
DQS falling edge hold time from CK
tDSH
0.2
–
0.2
–
tCK(avg)
30
DQS input HIGH pulse width
tDQSH
0.35
–
0.35
–
tCK(avg)
DQS input LOW pulse width
tDQSL
0.35
–
0.35
–
tCK(avg)
Write preamble
tWPRE
0.35
–
0.35
–
tCK(avg)
Write postamble
tWPST
0.4
0.6
0.4
0.6
tCK(avg)
10
Address and control input setup time
tIS(base)
200
–
175
–
ps
5, 7, 9, 22,
29
Address and control input hold time
tIH(base)
275
–
250
–
ps
5, 7, 9, 23,
29
Control & Address input pulse width for each
tIPW
input
0.6
–
0.6
–
tCK(avg)
DQ and DM input setup time
tDS(base)
50
–
50
–
ps
6, 7, 8, 20,
28, 31
DQ and DM input hold time
tDH(base)
175
–
125
–
ps
6, 7, 8, 21,
28, 31
DQ and DM input pulse width for each input
tDIPW
0.35
–
0.35
–
tCK(avg)
DQ output access time from CK/CK
tAC
- 450
450
- 400
400
ps
40
DQS output access time from CK/CK
tDQSCK
- 400
400
- 350
ps
40
Data-out high-impedance time from CK/CK
tHZ
–
tAC,max
–
ps
18,40
DQS/DQS low-impedance time from CK/CK
tLZ(DQS)
tAC,min
tAC,max
tAC,min
ps
18,40
DQ low-impedance time from CK/CK
tLZ(DQ)
350
tAC,
max
tAC,
max
tAC,
max
ps
18,40
DQS-DQ skew for DQS and associated DQ
signals
tDQSQ
CK half pulse width
tHP
DQ hold skew factor
Min.
Max.
Min.
Max
tCK(avg)
3
8
2.5
Average clock HIGH pulse width
tCH(avg)
0.45
0.55
Average clock LOW pulse width
tCL(avg)
0.45
DQS latching rising transitions to associated
clock edges
tDQSS
DQS falling edge to CK setup time
2 x tAC,min tAC,max 2 x tAC,min
–
240
–
200
ps
13
Min(
tCH(abs),
tCL(abs) )
–
Min(
tCH(abs),
tCL(abs) )
–
ps
37
tQHS
–
340
–
300
ps
38
DQ/DQS output hold time from DQS
tQH
tHP - tQHS
–
tHP - tQHS
–
ps
39
Read preamble
tRPRE
0.9
1.1
0.9
1.1
tCK(avg)
19,41
Read postamble
tRPST
0.4
0.6
0.4
0.6
tCK(avg)
19,42
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IS43/46DR81280C, IS43/46DR16640C
Timing parameters by speed grade (DDR2-667 and DDR2-800) cont'd
(For information related to the entries in this table, refer to both the Guidelines and the Specific Notes following this Table.)
Parameter
Activate to activate command period
Four Activate Window
DDR2-667
Symbol
Units Notes
Min.
Max
Min.
Max.
x8
7.5
–
7.5
–
x16
10
–
10
–
x8
37.5
–
35
–
ns
x16
50
–
45
–
ns
tRRD
tFAW
DDR2-800
ns
4,32
CAS to CAS command delay
tCCD
2
–
2
–
nCK
Write recovery time
tWR
15
–
15
–
ns
Auto precharge write recovery +
precharge time
tDAL
WR + tnRP
–
WR +
tnRP
–
Internal write to read command delay
tWTR
7.5
–
7.5
–
ns
24, 32
Internal read to precharge command
delay
tRTP
7.5
–
7.5
–
ns
3, 32
CKE minimum pulse width (HIGH and
LOW pulse width)
tCKE
3
–
3
–
tRFC + 10
–
tRFC + 10
–
ns
200
–
200
–
nCK
tXP
2
–
2
–
nCK
tXARD
2
–
2
–
nCK 1
Exit active power down to read
command (slow exit, lower power)
tXARDS
7 - AL
–
8 - AL
–
nCK 1, 2
ODT turn-on delay
tAOND
2
2
2
2
ODT turn-on
tAON
tAC, min
tAC,max + 0.7
tAC,min
tAC,max + 0.7
nCK 16
6, 16,
ns
40
ODT turn-on (Power-Down mode)
tAONPD
tAC, min + 2
2 x tCK(avg) +
tAC,max + 1
tAC,min
+2
2 x tCK(avg) +
tAC,max + 1
ODT turn-off delay
tAOFD
2.5
2.5
2.5
2.5
ODT turn-off
tAOF
tAC, min
tAC,max + 0.6
tAC,min
tAC,max + 0.6
ODT turn-off (Power-Down mode)
tAOFPD
tAC, min+2
ODT to power down entry latency
tANPD
3
ODT Power Down Exit Latency
tAXPD
Mode register set command cycle time
Exit self refresh to a non-read command tXSNR
Exit self refresh to a read command
Exit precharge power down to any
command
Exit active power down to read
command
tXSRD
2.5 x tCK(avg)
2.5 x tCK(avg) +
tAC,min+2
+ tAC,max + 1
tAC,max + 1
8
–
–
tMRD
2
OCD drive mode output delay
tOIT
Minimum time clocks remains ON after
CKE asynchronously drops LOW
tDelay
20
3
32
nCK 33
nCK 27
32
ns
nCK 17, 45
17,
ns
43, 45
ns
8
–
–
nCK
nCK
–
2
–
nCK
0
12
0
12
ns
32
tIS + tCK(avg)
+ tIH
–
tIS +
tCK(avg)
+ tIH
–
ns
15
Integrated Silicon Solution, Inc. — www.issi.com
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
Guidelines for AC Parameters
1. DDR2 SDRAM AC Timing Reference Load
Figure "AC Timing Reference Load" represents the timing reference load used in defining the relevant timing
parameters of the part. It is not intended to be either a precise representation of the typical system environment or
a depiction of the actual load presented by a production tester. System designers will use IBIS or other simulation
tools to correlate the timing reference load to a system environment. Manufacturers correlate to their production test
conditions (generally a coaxial transmission line terminated at the tester electronics).
VDDQ
DUT
DQ
DQS
DQS
RDQS
RDQS
Output
Timing
reference
point
VTT = VDDQ/2
25Ω
Figure - AC Timing Reference Load
The output timing reference voltage level for single ended signals is the crosspoint with VTT. The output timing
reference voltage level for differential signals is the crosspoint of the true (e.g. DQS) and the complement (e.g. DQS)
signal.
2. Slew Rate Measurement Levels
a) Output slew rate for falling and rising edges is measured between VTT - 250 mV and VTT + 250 mV for single
ended signals. For differential signals (e.g. DQS - DQS) output slew rate is measured between DQS - DQS = - 500 mV
and DQS - DQS = + 500 mV. Output slew rate is guaranteed by design, but is not necessarily tested on each device.
b) Input slew rate for single ended signals is measured from Vref(dc) to VIH(ac),min for rising edges and from Vref(dc)
to VIL(ac),max for falling edges.
For differential signals (e.g. CK - CK) slew rate for rising edges is measured from CK - CK = - 250 mV to CK - CK = +
500 mV (+ 250 mV to - 500 mV for falling edges).
c) VID is the magnitude of the difference between the input voltage on CK and the input voltage on CK, or between
DQS and DQS for differential strobe.
3. DDR2 SDRAM output slew rate test load
Output slew rate is characterized under the test conditions as shown in Figure "Slew Rate Test Load".
4. Differential data strobe
DDR2 SDRAM pin timings are specified for either single ended mode or differential mode depending on the setting of
the EMRS “Enable DQS” mode bit; timing advantages of differential mode are realized in system design. The method
by which the DDR2 SDRAM pin timings are measured is mode dependent. In single ended mode, timing relationships
are measured relative to the rising or falling edges of DQS crossing at VREF. In differential mode, these timing
VDDQ
DUT
DQ
DQS, DQS
Output
VTT = VDDQ/2
RDQS, RDQS
Test point
25Ω
Figure - Slew Rate Test Load
relationships are measured relative to the crosspoint of DQS and its complement, DQS. This distinction in timing
methods is guaranteed by design and characterization. Note that when differential data strobe mode is disabled via
the EMRS, the complementary pin, DQS, must be tied externally to VSS through a 20 Ω to 10 kΩ resistor to insure
proper operation.
Integrated Silicon Solution, Inc. — www.issi.com 21
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
tDQSH
DQS
DQS/
DQS
tDQSL
DQS
tWPRE
DQ
D
D
D
D
VIL(dc)
VIL(ac)
tDS
DM
tWPST
VIH(dc)
VIH(ac)
DMin
tDH
tDS
VIH(ac)
tDH
VIH(dc)
DMin
DMin
DMin
VIL(ac)
VIL(dc)
Data Input (Write) Timing
tCH
tCL
CK
CK/CK
CK
DQS
DQS/DQS
DQS
tRPRE
tRPST
DQ
Q
tDQSQmax
Q
Q
Q
tDQSQmax
tQH
tQH
Data Output (Read) Timing
5. AC timings are for linear signal transitions. See Specific Notes on derating for other signal transitions.
6. All voltages are referenced to VSS.
7. These parameters guarantee device behavior, but they are not necessarily tested on each device They may be
guaranteed by device design or tester correlation.
8. Tests for AC timing, IDD, and electrical (AC and DC) characteristics, may be conducted at nominal reference/supply
voltage levels, but the related specifications and device operation are guaranteed for the full voltage range specified.
Specific Notes for Dedicated AC Parameters
1. User can choose which active power down exit timing to use via Mode Register Set [A12]. tXARD is expected to be
used for fast active power down exit timing. tXARDS is expected to be used for slow active power down exit timing.
2. AL = Additive Latency.
3. This is a minimum requirement. Minimum read to precharge timing is AL + BL / 2 provided that the tRTP and
tRAS(min) have been satisfied.
4. A minimum of two clocks (2 x tCK or 2 x nCK) is required irrespective of operating frequency.
5. Timings are specified with command/address input slew rate of 1.0 V/ns. See Specific Notes on derating for other
slew rate values.
6. Timings are specified with DQs, DM, and DQS’s (DQS/RDQS in single ended mode) input slew rate of 1.0V/ns. See
Specific Notes on derating for other slew rate values.
22
Integrated Silicon Solution, Inc. — www.issi.com
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
7. Timings are specified with CK/CK differential slew rate of 2.0 V/ns. Timings are guaranteed for DQS signals with
a differential slew rate of 2.0 V/ns in differential strobe mode and a slew rate of 1 V/ns in single ended mode. See
Specific Notes on derating for other slew rate values.
8. Data setup and hold time derating (tds, tdh).
DtDS, DtDH derating values for DDR2-400, DDR2-553 (All units in ‘ps’; the note applies to the entire table)
DQS, DQS Differential Slew Rate
4.0 V/ns
3.0 V/ns
2.0 V/ns
1.8 V/ns
1.6 V/ns
1.4 V/ns
1.2 V/ns
1.0 V/ns
0.8 V/ns
DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH
DQ 2.0
Slew 1.5
rate 1.0
V/ns
0.9
0.8
0.7
0.6
0.5
0.4
125
45
125
45
125
45
-
-
83
21
83
21
83
0
0
0
0
0
-
-
-11
-14
-11
-14
-
-
-
-
-25
-31
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
21
95
33
0
12
12
1
-2
13
-13
-19
-1
-31
-42
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
24
24
-
-
-
-
-
-
-
-
-
-
-
10
25
22
-
-
-
-
-
-
-7
11
5
23
17
-
-
-
-
-19
-30
-7
-18
5
-6
17
6
-
-
-
-43
-59
-31
-47
-19
-35
-7
-23
5
-11
-
-
-
-74
-89
-62
-77
-50
-65
-38
-53
-
-
-
-
-
-127 -140 -115 -128 -103 -116
DDR2-400/533 tDS/tDH derating with differential data strobe
DtDS, DtDH derating values for DDR2-667, DDR2-800 (All units in ‘ps’; the note applies to the entire table)
DQS, DQS Differential Slew Rate
4.0 V/ns
3.0 V/ns
2.0 V/ns
1.8 V/ns
1.6 V/ns
1.4 V/ns
1.2 V/ns
1.0 V/ns
0.8 V/ns
DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH DtDS DtDH
DQ 2.0
Slew 1.5
rate 1.0
V/ns
0.9
0.8
0.7
0.6
0.5
0.4
100
67
0
-
45
21
0
-
100
67
0
-5
-
45
21
0
-14
-
100
67
0
-5
-13
-
45
21
0
-14
-31
-
79
12
7
-1
-10
-
33
12
-2
-19
-42
-
24
19
11
2
-10
-
24
10
-7
-30
-59
-
31
23
14
2
-24
-
22
5
-18
-47
-89
-
35 17
26
-6
38
6
14 -35 26 -23 38 -11
-12 -77
0
-65 12 -53
-52 -140 -40 -128 -28 -116
DDR2-667/800 tDS/tDH derating with differential data strobe
Integrated Silicon Solution, Inc. — www.issi.com 23
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
DtDS1, DtDH1 derating values for DDR2-400, DDR2-533 (All units in ‘ps’; the note applies to the entire table)
DQS, Single-ended Slew Rate
2.0 V/ns
1.5 V/ns
1.0 V/ns
DtDS1 DtDH1 DtDS1 DtDH1 DtDS1
DQ
Slew
rate
V/ns
DtDH
0.9 V/ns
0.8 V/ns
0.7 V/ns
0.6 V/ns
0.5 V/ns
0.4 V/ns
DtDS1 DtDH1 DtDS1 DtDH1 DtDS1 DtDH1 DtDS1 DtDH1 DtDS1 DtDH1 DtDS1 DtDH1
2.0
188
167
145
125
63
-
-
-
-
-
-
-
-
-
-
-
-
-
1.5
1.0
0.9
0.8
0.7
0.6
0.5
0.4
146
63
-
167
125
-
125
42
31
-
125
83
69
-
83
0
-11
-25
-
42
0
-14
-31
-
81
-2
-13
-27
-45
-
43
1
-13
-30
-53
-
-7
-18
-32
-50
-74
-
-13
-27
-44
-67
-96
-
-29
-43
-61
-85
-128
-
-45
-62
-85
-114
-156
-
-60
-78
-102
-145
-210
-86
-109
-138
-180
-243
-108
-132
-175
-240
-152
-181
-223
-286
-183
-226
-291
-246
-288
-351
DDR2-400/533 tDS1/tDH1 derating with single-ended data strobe
For all input signals the total tDS (setup time) and tDH (hold time) required is calculated by adding the data sheet
tDS(base) and tDH(base) value to the DtDS and DtDH derating value respectively. Example: tDS (total setup time) =
tDS(base) + DtDS.
Setup (tDS) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of VREF(dc) and
the first crossing of Vih(ac)min. Setup (tDS) nominal slew rate for a falling signal is defined as the slew rate between
the last crossing of VREF(dc) and the first crossing of Vil(ac)max. If the actual signal is always earlier than the nominal
slew rate line between shaded ‘VREF(dc) to ac region’, use nominal slew rate for derating value. If the actual signal is
later than the nominal slew rate line anywhere between shaded ‘VREF(dc) to ac region’, the slew rate of a tangent line
to the actual signal from the ac level to dc level is used for derating value.
Hold (tDH) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of Vil(dc)max and
the first crossing of VREF(dc). Hold (tDH) nominal slew rate for a falling signal is defined as the slew rate between the
last crossing of Vih(dc)min and the first crossing of VREF(dc). If the actual signal is always later than the nominal slew
rate line between shaded ‘dc level to VREF(dc) region’, use nominal slew rate for derating value. If the actual signal is
earlier than the nominal slew rate line anywhere between shaded ‘dc to VREF(dc) region’, the slew rate of a tangent
line to the actual signal from the dc level to VREF(dc) level is used for derating value.
Although for slow slew rates the total setup time might be negative (i.e. a valid input signal will not have reached VIH/
IL(ac) at the time of the rising clock transition) a valid input signal is still required to complete the transition and reach
VIH/IL(ac).
For slew rates in between the values listed in the "Data Setup and Hold Time Derating" tables, the derating values
may obtained by linear interpolation.
These values are typically not subject to production test. They are verified by design and characterization.
24
Integrated Silicon Solution, Inc. — www.issi.com
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
9. Input Setup and Hold Time Derating (tIS, tIH)
tIS, tIH Derating Values for DDR2-400, DDR2-533
CK, /CK Differential Slew Rate
2.0 V/ns
Command/
Address
Slew rate
(V/ns)
1.5 V/ns
1.0 V/ns
Units
Notes
∆tIS
∆tIH
∆tIS
∆tIH
∆tIS
∆tIH
4.0
187
94
217
124
247
154
ps
1
3.5
179
89
209
119
239
149
ps
1
3
167
83
197
113
227
143
ps
1
2.5
150
75
180
105
210
135
ps
1
2.0
125
45
155
75
185
105
ps
1
1.5
83
21
113
51
143
81
ps
1
1.0
0
0
30
30
60
60
ps
1
0.9
-11
-14
19
16
49
46
ps
1
0.8
-25
-31
5
-1
35
29
ps
1
0.7
-43
-54
-13
-24
17
6
ps
1
0.6
-67
-83
-37
-53
-7
-23
ps
1
0.5
-110
-125
-80
-95
-50
-65
ps
1
0.4
-175
-188
-145
-158
-115
-128
ps
1
0.3
-285
-292
-255
-262
-225
-232
ps
1
0.25
-350
-375
-320
-345
-290
-315
ps
1
0.2
-525
-500
-495
-470
-465
-440
ps
1
0.15
-800
-708
-770
-678
-740
-648
ps
1
0.1
-1450
-1125
-1420
-1095
-1390
-1065
ps
1
Integrated Silicon Solution, Inc. — www.issi.com 25
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
∆tIS and ∆tIH Derating Values for DDR2-667, DDR2-800
CK,CK Differential Slew Rate
2.0 V/ns
1.5 V/ns
1.0 V/ns
Units
Notes
∆tIS
∆tIH
∆tIS
∆tIH
∆tIS
∆tIH
4
150
94
180
124
210
154
ps
1
3.5
143
89
173
119
203
149
ps
1
3
133
83
163
113
193
143
ps
1
2.5
120
75
150
105
180
135
ps
1
2
100
45
130
75
160
105
ps
1
1.5
67
21
97
51
127
81
ps
1
1
0
0
30
30
60
60
ps
1
Command/
0.9
-5
-14
25
16
55
46
ps
1
Address
0.8
-13
-31
17
-1
47
29
ps
1
Slew rate
0.7
-22
-54
8
-24
38
6
ps
1
(V/ns)
0.6
-34
-83
-4
-53
26
-23
ps
1
0.5
-60
-125
-30
-95
0
-65
ps
1
0.4
-100
-188
-70
-158
-40
-128
ps
1
0.3
-168
-292
-138
-262
-108
-232
ps
1
0.25
-200
-375
-170
-345
-140
-315
ps
1
0.2
-325
-500
-295
-470
-265
-440
ps
1
0.15
-517
-708
-487
-678
-457
-648
ps
1
0.1
-1000
-1125
-970
-1095
-940
-1065
ps
1
For all input signals the total tIS (setup time) and tIH (hold time) required is calculated by adding the data sheet
tIS(base) and tIH(base) value to the ∆tIS and ∆tIH derating value respectively. Example: tIS (total setup time) =
tIS(base) + ∆tIS
Setup (tIS) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of VREF(dc) and
the first crossing of Vih(ac)min. Setup (tIS) nominal slew rate for a falling signal is defined as the slew rate between
the last crossing of VREF(dc) and the first crossing of Vil(ac)max. If the actual signal is always earlier than the nominal
slew rate line between shaded ‘VREF(dc) to ac region’, use nominal slew rate for derating value. If the actual signal is
later than the nominal slew rate line anywhere between shaded ‘VREF(dc) to ac region’, the slew rate of a tangent line
to the actual signal from the ac level to dc level is used for derating value.
Hold (tIH) nominal slew rate for a rising signal is defined as the slew rate between the last crossing of Vil(dc)max and
the first crossing of VREF(dc). Hold (tIH) nominal slew rate for a falling signal is defined as the slew rate between
the last crossing of Vih(dc)min and the first crossing of VREF(dc). If the actual signal is always later than the nominal
slew rate line between shaded ‘dc to VREF(dc) region’, use nominal slew rate for derating value. If the actual signal is
earlier than the nominal slew rate line anywhere between shaded ‘dc to VREF(dc) region’, the slew rate of a tangent
line to the actual signal from the dc level to VREF(dc) level is used for derating value.
Although for slow slew rates the total setup time might be negative (i.e. a valid input signal will not have reached VIH/
IL(ac) at the time of the rising clock transition) a valid input signal is still required to complete the transition and reach
VIH/IL(ac).
For slew rates in between the values listed in the "Input Setup and Hold Time Derating" tables, the derating values
may obtained by linear interpolation.
These values are typically not subject to production test. They are verified by design and characterization.
26
Integrated Silicon Solution, Inc. — www.issi.com
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
10. The maximum limit for this parameter is not a device limit. The device will operate with a greater value for this
parameter, but system performance (bus turnaround) will degrade accordingly.
11. MIN ( tCL, tCH) refers to the smaller of the actual clock LOW time and the actual clock HIGH time as provided to
the device (i.e. this value can be greater than the minimum specification limits for tCL and tCH). For example, tCL and
tCH are = 50% of the period, less the half period jitter ( tJIT(HP)) of the clock source, and less the half period jitter due
to crosstalk ( tJIT(crosstalk)) into the clock traces.
12. tQH = tHP – tQHS, where:
t HP = minimum half clock period for any given cycle and is defined by clock HIGH or clock LOW (tCH, tCL). tQHS
accounts for:
1) The pulse duration distortion of on-chip clock circuits; and
2) The worst case push-out of DQS on one transition followed by the worst case pull-in of DQ on the next transition,
both of which are, separately, due to data pin skew and output pattern effects, and p-channel to n-channel variation of
the output drivers.
13. tDQSQ: Consists of data pin skew and output pattern effects, and p-channel to n-channel variation of the output
drivers as well as output slew rate mismatch between DQS / DQS and associated DQ in any given cycle.
14. tDAL = WR + RU{ tRP[ns] / tCK[ns] }, where RU stands for round up.
WR refers to the tWR parameter stored in the MRS. For tRP, if the result of the division is not already an integer, round
up to the next highest integer. tCK refers to the application clock period.
Example: For DDR533 at tCK = 3.75ns with WR programmed to 4 clocks.
tDAL = 4 + (15 ns / 3.75 ns) clocks = 4 + (4) clocks = 8 clocks.
15. The clock frequency is allowed to change during self–refresh mode or precharge power-down mode. In case of
clock frequency change during precharge power-down, a specific procedure is required as described in section 3.13.
16. 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 measured from tAOND, which is interpreted differently
per speed bin. For DDR2-400/533, tAOND is 10 ns (= 2 x 5 ns) after the clock edge that registered a first ODT HIGH
if tCK = 5 ns. For DDR2-667/800, tAOND is 2 clock cycles after the clock edge that registered a first ODT HIGH
counting the actual input clock edges.
17. 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, which is interpreted differently per speed bin. For
DDR2-400/533, tAOFD is 12.5 ns (= 2.5 x 5 ns) after the clock edge that registered a first ODT LOW if tCK = 5 ns.
For DDR2-667/800, if tCK(avg) = 3 ns is assumed, tAOFD is 1.5 ns (= 0.5 x 3 ns) after the second trailing clock edge
counting from the clock edge that registered a first ODT LOW and by counting the actual input clock edges.
18. tHZ and tLZ transitions occur in the same access time as valid data transitions. These parameters are referenced
to a specific voltage level which specifies when the device output is no longer driving (tHZ), or begins driving (tLZ) .
One method to calculate the point when device is no longer driving (tHZ), or begins driving (tLZ) is by measuring the
signal at two different voltages. The actual voltage measurement points are not critical as long as the calculation is
consistent. tLZ(DQ) refers to tLZ of the DQ’s and tLZ(DQS) refers to tLZ of the (U/L/R)DQS and (U/L/R)DQS each
treated as single-ended signal.
19. tRPST end point and tRPRE begin point are not referenced to a specific voltage level but specify when the device
output is no longer driving (tRPST), or begins driving (tRPRE). One method to calculate these points when the device
is no longer driving (tRPST), or begins driving (tRPRE) is by measuring the signal at two different voltages. The actual
voltage measurement points are not critical as long as the calculation is consistent.
Integrated Silicon Solution, Inc. — www.issi.com 27
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
20. Input waveform timing tDS with differential data strobe enabled is referenced from the input signal crossing at
the VIH(ac) level to the differential data strobe crosspoint for a rising signal, and from the input signal crossing at the
VIL(ac) level to the differential data strobe crosspoint for a falling signal applied to the device under test. DQS, DQS
signals must be monotonic between Vil(dc)max and Vih(dc)min.
21. Input waveform timing tDH with differential data strobe enabled is referenced from the differential data strobe
crosspoint to the input signal crossing at the VIH(dc) level for a falling signal and from the differential data strobe
crosspoint to the input signal crossing at the VIL(dc) level for a rising signal applied to the device under test. DQS,
DQS signals must be monotonic between Vil(dc)max and Vih(dc)min.
22. Input waveform timing is referenced from the input signal crossing at the VIH(ac) level for a rising signal and
VIL(ac) for a falling signal applied to the device under test.
23. Input waveform timing is referenced from the input signal crossing at the VIL(dc) level for a rising signal and
VIH(dc) for a falling signal applied to the device under test.
24. tWTR is at lease two clocks (2 x tCK or 2 x nCK) independent of operation frequency.
25. Input waveform timing with single-ended data strobe enabled, is referenced from the input signal crossing at the
VIH(ac) level to the single-ended data strobe crossing VIH/L(dc) at the start of its transition for a rising signal, and
from the input signal crossing at the VIL(ac) level to the single-ended data strobe crossing VIH/L(dc) at the start of its
transition for a falling signal applied to the device under test. The DQS signal must be monotonic between Vil(dc)max
and Vih(dc)min.
26. Input waveform timing with single-ended data strobe enabled, is referenced from the input signal crossing at the
VIH(dc) level to the single-ended data strobe crossing VIH/L(ac) at the end of its transition for a rising signal, and
from the input signal crossing at the VIL(dc) level to the single-ended data strobe crossing VIH/L(ac) at the end of its
transition for a falling signal applied to the device under test. The DQS signal must be monotonic between Vil(dc)max
and Vih(dc)min.
27. tCKEmin of 3 clocks means CKE must be registered on three consecutive positive clock edges. CKE must remain
at the valid input level the entire time it takes to achieve the 3 clocks of registration. Thus, after any CKE transition,
CKE may not transition from its valid level during the time period of tIS + 2 x tCK + tIH.
28. If tDS or tDH is violated, data corruption may occur and the data must be re-written with valid data before a valid
READ can be executed.
29. These parameters are measured from a command/address signal (CKE, CS, RAS, CAS, WE, ODT, BA0, A0, A1,
etc.) transition edge to its respective clock signal (CK/CK) crossing. The spec values are not affected by the amount
of clock jitter applied (i.e. tJIT(per), tJIT(cc), etc.), as the setup and hold are relative to the clock signal crossing that
latches the command/address. That is, these parameters should be met whether clock jitter is present or not.
30. These parameters are measured from a data strobe signal ((L/U/R)DQS/DQS) crossing to its respective clock
signal (CK/CK) crossing. The spec values are not affected by the amount of clock jitter applied (i.e. tJIT(per), tJIT(cc),
etc.), as these are relative to the clock signal crossing. That is, these parameters should be met whether clock jitter is
present or not.
31. These parameters are measured from a data signal ((L/U)DM, (L/U)DQ0, (L/U)DQ1, etc.) transition edge to its
respective data strobe signal ((L/U/R)DQS/ DQS) crossing.
32. For these parameters, the DDR2 SDRAM device is characterized and verified to support tnPARAM = RU{tPARAM
/ tCK(avg)}, which is in clock cycles, assuming all input clock jitter specifications are satisfied.
For example, the device will support tnRP = RU{tRP / tCK(avg)}, which is in clock cycles, if all input clock jitter
specifications are met. This means: For DDR2-667 5-5-5, of which tRP = 15ns, the device will support tnRP = RU{tRP
/ tCK(avg)} = 5, i.e. as long as the input clock jitter specifications are met, Precharge command at Tm and Active
command at Tm+5 is valid even if (Tm+5 - Tm) is less than 15ns due to input clock jitter.
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33. tDAL [nCK] = WR [nCK] + tnRP [nCK] = WR + RU {tRP [ps] / tCK(avg) [ps] }, where WR is the value programmed
in the mode register set.
34. New units, ‘tCK(avg)’ and ‘nCK’, are introduced in DDR2-667 and DDR2-800.
Unit ‘tCK(avg)’ represents the actual tCK(avg) of the input clock under operation.
Unit ‘nCK’ represents one clock cycle of the input clock, counting the actual clock edges.
Note that in DDR2-400 and DDR2-533, ‘tCK’ is used for both concepts.
ex) tXP = 2 [nCK] means; if Power Down exit is registered at Tm, an Active command may be registered at Tm+2,
even if (Tm+2 - Tm) is 2 x tCK(avg) + tERR(2per),min.
35. Input clock jitter spec parameter. These parameters and the ones in the table below are referred to as 'input clock
jitter spec parameters' and these parameters apply to DDR2-667 and DDR2-800 only. The jitter specified is a random
jitter meeting a Gaussian distribution.
Parameter
Symbol
DDR2-667
DDR2-800
min
max
min
max
Units
Notes
Clock period jitter
tJIT(per)
-125
125
-100
100
ps
35
Clock period jitter during DLL locking
period
tJIT(per,lck)
-100
100
-80
80
ps
35
Cycle to cycle clock period jitter
tJIT(cc
-250
250
-200
200
ps
35
Cycle to cycle clock period jitter during
DLL locking period
tJIT(cc,lck)
-200
200
-160
160
ps
35
Cumulative error across 2 cycles
tERR(2per)
-175
175
-150
150
ps
35
Cumulative error across 3 cycles
tERR(3per)
-225
225
-175
175
ps
35
Cumulative error across 4 cycles
tERR(4per)
-250
250
-200
200
ps
35
Cumulative error across 5 cycles
tERR(5per)
-250
250
-200
200
ps
35
Cumulative error across n cycles, n = 6 ...
10, inclusive
tERR(610per)
-350
350
-300
300
ps
35
Cumulative error across n cycles, n = 11
... 50, inclusive
tERR(1150per)
-450
450
-450
450
ps
35
Duty cycle jitter
tJIT(duty)
-125
125
-100
100
ps
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36. These parameters are specified per their average values, however it is understood that the following relationship
between the average timing and the absolute instantaneous timing holds at all times. (Min and max of SPEC values
are to be used for calculations in the table below.)
Parameter
Symbol
min
max
Units
Absolute clock period
tCK(abs)
tCK(avg),min + tJIT(per),min
tCK(avg),max + tJIT(per),max
ps
Absolute clock HIGH
pulse width
tCH(abs)
tCH(avg),min x tCK(avg),min +
tJIT(duty),min
tCH(avg),max x tCK(avg),max +
tJIT(duty),max
ps
Absolute clock LOW
pulse width
tCL(abs)
tCL(avg),min x tCK(avg),min +
tJIT(duty),min
tCL(avg),max x tCK(avg),max +
tJIT(duty),max
ps
Example: For DDR2-667, tCH(abs),min = ( 0.48 x 3000 ps ) - 125 ps = 1315 ps
37. tHP is the minimum of the absolute half period of the actual input clock. tHP is an input parameter but not an input
specification parameter. It is used in conjunction with tQHS to derive the DRAM output timing tQH.
The value to be used for tQH calculation is determined by the following equation;
tHP = Min ( tCH(abs), tCL(abs) ),
where,
tCH(abs) is the minimum of the actual instantaneous clock HIGH time;
tCL(abs) is the minimum of the actual instantaneous clock LOW time;
38. tQHS accounts for:
1) The pulse duration distortion of on-chip clock circuits, which represents how well the actual tHP at the input is
transferred to the output; and
2) The worst case push-out of DQS on one transition followed by the worst case pull-in of DQ on the next transition,
both of which are independent of each other, due to data pin skew, output pattern effects, and pchannel to n-channel
variation of the output drivers
39. tQH = tHP – tQHS, where:
tHP is the minimum of the absolute half period of the actual input clock; and
tQHS is the specification value under the max column.
{The less half-pulse width distortion present, the larger the tQH value is; and the larger the valid data eye will be.}
Examples:
1) If the system provides tHP of 1315 ps into a DDR2-667 SDRAM, the DRAM provides tQH of 975 ps minimum.
2) If the system provides tHP of 1420 ps into a DDR2-667 SDRAM, the DRAM provides tQH of 1080 ps minimum.
40. When the device is operated with input clock jitter, this parameter needs to be derated by the actual tERR(610per) of the input clock. (output deratings are relative to the SDRAM input clock.)
For example, if the measured jitter into a DDR2-667 SDRAM has tERR(6-10per),min = - 272 ps and tERR(6-10per),
max = + 293 ps, then tDQSCK,min(derated) = tDQSCK,min - tERR(6-10per),max = - 400 ps - 293 ps = - 693 ps and
tDQSCK,max(derated) = tDQSCK,max - tERR(6-10per),min = 400 ps + 272 ps = + 672 ps. Similarly, tLZ(DQ) for
DDR2-667 derates to tLZ(DQ),min(derated) = - 900 ps - 293 ps = - 1193 ps and tLZ(DQ),max(derated) = 450 ps + 272
ps = + 722 ps. (Caution on the min/max usage!)
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41. When the device is operated with input clock jitter, this parameter needs to be derated by the actual tJIT(per) of
the input clock. (output deratings are relative to the SDRAM input clock.)
For example, if the measured jitter into a DDR2-667 SDRAM has tJIT(per),min = - 72 ps and tJIT(per),max = + 93 ps,
then tRPRE,min(derated) = tRPRE,min + tJIT(per),min = 0.9 x tCK(avg) - 72 ps = + 2178 ps and tRPRE,max(derated)
= tRPRE,max + tJIT(per),max = 1.1 x tCK(avg) + 93 ps = + 2843 ps. (Caution on the min/max usage!)
42. When the device is operated with input clock jitter, this parameter needs to be derated by the actual tJIT(duty) of
the input clock. (output deratings are relative to the SDRAM input clock.)
For example, if the measured jitter into a DDR2-667 SDRAM has tJIT(duty),min = - 72 ps and tJIT(duty),max
= + 93 ps, then tRPST,min(derated) = tRPST,min + tJIT(duty),min = 0.4 x tCK(avg) - 72 ps = + 928 ps and
tRPST,max(derated) = tRPST,max + tJIT(duty),max = 0.6 x tCK(avg) + 93 ps = + 1592 ps. (Caution on the min/max
usage!)
43. When the device is operated with input clock jitter, this parameter needs to be derated by { -tJIT(duty),max tERR(6-10per),max } and { - tJIT(duty),min - tERR(6-10per),min } of the actual input clock. (output deratings are
relative to the SDRAM input clock.)
For example, if the measured jitter into a DDR2-667 SDRAM has tERR(6-10per),min = - 272 ps, tERR(6-10per),max =
+ 293 ps, tJIT(duty),min = - 106 ps and tJIT(duty),max = + 94 ps, then tAOF,min(derated) = tAOF,min + { - tJIT(duty),
max - tERR(6-10per),max } = - 450 ps + { - 94 ps - 293 ps} = - 837 ps and tAOF,max(derated) = tAOF,max + { tJIT(duty),min - tERR(6-10per),min } = 1050 ps + { 106 ps + 272 ps } = + 1428 ps. (Caution on the min/max usage!)
44. For tAOFD of DDR2-400/533, the 1/2 clock of tCK in the 2.5 x tCK assumes a tCH, input clock HIGH pulse width
of 0.5 relative to tCK. tAOF,min and tAOF,max should each be derated by the same amount as the actual amount of
tCH offset present at the DRAM input with respect to 0.5. For example, if an input clock has a worst case tCH of 0.45,
the tAOF,min should be derated by subtracting 0.05 x tCK from it, whereas if an input clock has a worst case tCH of
0.55, the tAOF,max should be derated by adding 0.05 x tCK to it. Therefore, we have;
tAOF,min(derated) = tAC,min - [0.5 - Min(0.5, tCH,min)] x tCK
tAOF,max(derated) = tAC,max + 0.6 + [Max(0.5, tCH,max) - 0.5] x tCK
or
tAOF,min(derated) = Min(tAC,min, tAC,min - [0.5 - tCH,min] x tCK)
tAOF,max(derated) = 0.6 + Max(tAC,max, tAC,max + [tCH,max - 0.5] x tCK)
where tCH,min and tCH,max are the minimum and maximum of tCH actually measured at the DRAM input balls.
45. For tAOFD of DDR2-667/800, the 1/2 clock of nCK in the 2.5 x nCK assumes a tCH(avg), average input clock
HIGH pulse width of 0.5 relative to tCK(avg). tAOF,min and tAOF,max should each be derated by the same amount
as the actual amount of tCH(avg) offset present at the DRAM input with respect to 0.5. For example, if an input clock
has a worst case tCH(avg) of 0.48, the tAOF,min should be derated by subtracting 0.02 x tCK(avg) from it, whereas
if an input clock has a worst case tCH(avg) of 0.52, the tAOF,max should be derated by adding 0.02 x tCK(avg) to it.
Therefore, we have;
tAOF,min(derated) = tAC,min - [0.5 - Min(0.5, tCH(avg),min)] x tCK(avg)
tAOF,max(derated) = tAC,max + 0.6 + [Max(0.5, tCH(avg),max) - 0.5] x tCK(avg)
or
tAOF,min(derated) = Min(tAC,min, tAC,min - [0.5 - tCH(avg),min] x tCK(avg))
tAOF,max(derated) = 0.6 + Max(tAC,max, tAC,max + [tCH(avg),max - 0.5] x tCK(avg))
where tCH(avg),min and tCH(avg),max are the minimum and maximum of tCH(avg) actually measured at the DRAM
input balls.
Note that these deratings are in addition to the tAOF derating per input clock jitter, i.e. tJIT(duty) and tERR(6-10per).
However tAC values used in the equations shown above are from the timing parameter table and are not derated.
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Thus the final derated values for tAOF are;
tAOF,min(derated_final) = tAOF,min(derated) + { - tJIT(duty),max - tERR(6-10per),max }
tAOF,max(derated_final) = tAOF,max(derated) + { - tJIT(duty),min - tERR(6-10per),min }
46. Flexibility is provided for the absolute refresh interval. A maximum of 8 Refresh commands can be posted to the
DRAM, meaning that the maximum absolute interval between any refresh command and the next Refresh command
is 9x tREFI.
FUNCTIONAL DESCRIPTION
Power-up and Initialization
DDR2 SDRAMs must be powered up and initialized in a predefined manner. Operational procedures other than those
specified may result in undefined operation. For DDR2 SDRAMs, both bits BA0 and BA1 must be decoded for Mode/
Extended Mode Register Set (MRS/EMRS) commands. Users must initialize all four Mode Registers. The registers
may be initialized in any order.
Power-up and Initialization Sequence
The following sequence is required for Power-up and Initialization.
a) Either one of the following sequence is required for Power-up.
a1) While applying power, attempt to maintain CKE below 0.2 x VDDQ and ODT*1 at a LOW state (all other
inputs may be undefined.) The VDD voltage ramp time must be no greater than 200 ms from when VDD ramps
from 300 mV to VDD min; and during the VDD voltage ramp, |VDD-VDDQ| ≤ 0.3 volts. Once the ramping of the
supply voltages is complete (when VDDQ crosses VDDQ min), the supply voltage specifications provided in
"Recommended DC operating conditions" (SSTL_1.8), prevail.
- VDD, VDDL and VDDQ are driven from a single power converter output, AND
- VTT is limited to 0.95V max, AND
- VREF tracks VDDQ/2, VREF must be within +/- 300mV with respect to VDDQ/2 during supply ramp time.
- VDDQ ≥ VREF must be met at all times.
a2) While applying power, attempt to maintain CKE below 0.2 x VDDQ and ODT*1 at a LOW state, all other inputs
may be undefined, voltage levels at I/Os and outputs must be less than VDDQ during voltage ramp time to avoid
DRAM latch-up. During the ramping of the supply voltages, VDD ≥ VDDL ≥ VDDQ must be maintained and is
applicable to both AC and DC levels until the ramping of the supply voltages is complete, which is when VDDQ
crosses VDDQ min. Once the ramping of the supply voltages is complete, the supply voltage specifications provided
in "Recommended DC operating conditions" (SSTL_1.8), prevail.
- Apply VDD/VDDL before or at the same time as VDDQ.
- VDD/VDDL voltage ramp time must be no greater than 200ms from when VDD ramps from 300mV to VDD min
- Apply VDDQ before or at the same time as VTT.
- The VDDQ voltage ramp time from when VDD min is achieved on VDD to when VDDQ min is achieved on VDDQ
must be no greater than 500ms.
(Note: While VDD is ramping, current may be supplied from VDD through the DRAM to VDDQ.)
- VREF must track VDDQ/2, VREF must be within +/- 300mv with respect to VDDQ/2 during supply ramp time.
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- VDDQ ≥ VREF must be met at all times.
- Apply VTT.
- The VTT voltage ramp time from when VDDQ min is achieved on VDDQ to when VTT min is achieved on VTT must
be no greater than 500ms.
b) Start clock and maintain stable condition.
c) For the minimum of 200ms after stable power (VDD, VDDL, VDDQ, VREF and VTT are between their minimum and
maximum values as stated in "Recommended DC operating conditions" (SSTL_1.8)) and stable clock (CK, CK), then
apply NOP or Deselect & take CKE HIGH.
d) Wait minimum of 400ns then issue precharge all command. NOP or Deselect applied during 400 ns period.
e) Issue an EMRS command to EMR(2).
Power-up and Initialization Sequence (cont'd)
f) Issue an EMRS command to EMR(3).
g) Issue EMRS to enable DLL.
h) Issue a Mode Register Set command for DLL reset.
i) Issue a precharge all command.
j) Issue 2 or more auto-refresh commands.
k) Issue a MRS command with LOW to A8 to initialize device operation. (i.e. to program operating parameters without
resetting the DLL.)
l) At least 200 clocks after step h, execute OCD Calibration. This is done by EMRS to EMR(1) to set OCD Calibration
Default (A9=A8=A7=HIGH) followed by EMRS to EMR(1) to exit OCD Calibration Mode (A9=A8=A7=LOW) must be
issued with other operating parameters of EMR(1).
m) The DDR2 SDRAM is now ready for normal operation.
tCH tCL
CK
/CK
tIS
CKE
tIS
ODT
Command
PRE
ALL
NOP
400ns
tRP
PRE
ALL
MRS
EMRS
tMRD
tMRD
DLL
ENABLE
DLL
RESET
REF
tRP
MRS
REF
tRFC
tRFC
EMRS
tMRD
ANY
CMD
EMRS
Follow OCD
Flowchart
tOIT
min 200 Cycle
OCD
Default
OCD
CAL. MODE
EXIT
Initialization Sequence after Power-Up
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Programming the Mode and Extended Mode Registers
For application flexibility, burst length, burst type, CAS latency, DLL reset function, write recovery time (WR) are user
defined variables and must be programmed with a Mode Register Set (MRS) command. Additionally, DLL disable
function, driver impedance, additive CAS latency, ODT (On Die Termination), single-ended strobe, and OCD (off chip
driver impedance adjustment) are also user defined variables and must be programmed with an Extended Mode
Register Set (EMRS) command. Contents of the Mode Register or Extended Mode Registers can be altered by reexecuting the MRS or EMRS Commands. Even if the user chooses to modify only a subset of the MR, or EMR(1),
EMR(2), or EMR(3) variables, all variables within the addressed register must be redefined when the MRS or EMRS
commands are issued.
MRS, EMRS and Reset DLL do not affect memory array contents, which means re-initialization including those can be
executed at any time after power-up without affecting memory array contents.
Mode Register (MR)
The mode register stores the data for controlling the various operating modes of the DDR2 SDRAM. It controls CAS
latency, burst length, burst sequence, test mode, DLL reset, and Write Recovery time (WR) to make DDR2 SDRAM
useful for various applications. The default value of the mode register is not defined, therefore the mode register
must be programmed during initialization for proper operation. The mode register is written by asserting LOW on
CS, RAS, CAS, WE, BA0, BA1 and BA2, while controlling the state of address pins A0-A13(x8) or A0-A12(x16). The
DDR2 SDRAM should be in all bank precharge state with CKE already HIGH prior to writing into the mode register.
The mode register set command cycle time (tMRD) is required to complete the write operation to the mode register.
The mode register contents can be changed using the same command and clock cycle requirements during normal
operation as long as all banks are in the precharge state. The mode register is divided into various fields depending on
functionality. Burst length is defined by A0 - A2 with options of 4 and 8 bit burst lengths. The burst length decodes are
compatible with DDR SDRAM. Burst address sequence type is defined by A3, CAS latency is defined by A4 - A6. The
DDR2 does not support half clock latency mode. A7 is a mode bit and must be set to LOW for normal MRS operation.
A8 is used for DLL reset. Write recovery time WR is defined by A9 - A11. Refer to the table for specific codes.
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DDR2 SDRAM Mode Register Set (MRS)
Address
Field
BA1
Mode
Register
A12
0
0
Fast exit (use tXARD)
1
Slow exit(use tXARDS)
BA0
0
A13
0
A12
PD
A11
A10
WR
A9
A8
A7
DLL
TM
A6
A5
CAS
Latency
A4
A3
BT
A2
A1
A0
Burst
Length
Active power down exit time
A11
A10
A9
0
0
0
WR(cycles)*1
Reserved
0
0
1
2
0
1
0
3
0
1
1
4
1
0
0
5
1
0
1
6
1
1
0
7
1
1
1
8
A8
DLL Reset
A7
Mode
0
No
0
Normal
1
Yes
1
Reserved
A6
A5
A4
CAS Latency
0
0
0
Reserved
0
0
1
Reserved
0
1
0
Reserved
0
1
1
1
0
0
32
42
1
0
1
52
1
1
0
1
1
1
62
72
A3
Burst Type
A2
A1
A0
BL
0
Sequential
0
1
0
4
1
Interleave
0
1
1
8
Notes:
1. For DDR2-400/533, WR (write recovery for autoprecharge) min is determined by tCK max and WR max is determined by tCK min. WR in clock
cycles is calculated by dividing tWR (in ns) by tCK (in ns) and rounding up to the next integer (WR[cycles] = RU{ tWR[ns] / tCK[ns] }, where RU
stands for round up). For DDR2-667/800, WR min is determined by tCK(avg) max and WR max is determined by tCK(avg) min. WR[cycles] =
RU{ tWR[ns] / tCK(avg)[ns] }, where RU stands for round up. The mode register must be programmed to this value. This is also used with tRP
to determine tDAL.
2. Speed bin determined. Refer to Key Timing Parameter table.
3. A13, only applicable for x8.
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Burst mode operation
Burst mode operation is used to provide a constant flow of data to memory locations (write cycle), or from memory
locations (read cycle). The parameters that define how the burst mode will operate are burst sequence and burst
length. DDR2 SDRAM supports 4 bit burst and 8 bit burst modes only. For 8 bit burst mode, full interleave address
ordering is supported, however, sequential address ordering is nibble based for ease of implementation. The burst
type, either sequential or interleaved, is programmable and defined by MR[A3], which is similar to the DDR SDRAM
operation. Seamless burst read or write operations are supported. Unlike DDR devices, interruption of a burst read or
write cycle during BL = 4 mode operation is prohibited. However in case of BL = 8 mode, interruption of a burst read or
write operation is limited to two cases, reads interrupted by a read, or writes interrupted by a write. Therefore the Burst
Stop command is not supported on DDR2 SDRAM devices.
Burst Length and Sequence
Burst Length Starting Address (A1, A0)
4
Sequential Addressing (decimal)
Interleave Addressing (decimal)
00
0, 1, 2, 3
0, 1, 2, 3
01
1, 2, 3, 0
1, 0, 3, 2
10
2, 3, 0, 1
2, 3, 0, 1
11
3, 0, 1, 2
3, 2, 1, 0
Burst Length Starting Address (A2, A1, A0)
8
36
Sequential Addressing (decimal)
Interleave Addressing (decimal)
000
0, 1, 2, 3, 4, 5, 6, 7
0, 1, 2, 3, 4, 5, 6, 7
001
1, 2, 3, 0, 5, 6, 7, 4
1, 0, 3, 2, 5, 4, 7, 6
010
2, 3, 0, 1, 6, 7, 4, 5
2, 3, 0, 1, 6, 7, 4, 5
011
3, 0, 1, 2, 7, 4, 5, 6
3, 2, 1, 0, 7, 6, 5, 4
100
4, 5, 6, 7, 0, 1, 2, 3
4, 5, 6, 7, 0, 1, 2, 3
101
5, 6, 7, 4, 1, 2, 3, 0
5, 4, 7, 6, 1, 0, 3, 2
110
6, 7, 4, 5, 2, 3, 0, 1
6, 7, 4, 5, 2, 3, 0, 1
111
7, 4, 5, 6, 3, 0, 1, 2
7, 6, 5, 4, 3, 2, 1, 0
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Extended Mode Registers (EMR)
Extended Mode Register 1 (EMR1)
The EMR(1) stores the data for enabling or disabling the DLL, output driver strength, additive latency, ODT, DQS
disable, OCD program, RDQS enable. The default value of the EMR(1) is not defined, therefore the extended mode
register must be programmed during initialization for proper operation. The EMR(1) is written by asserting LOW
on CS, RAS, CAS, WE, HIGH on BA0 and LOW on BA1 and BA2, while controlling the states of address pins A0 A13. The DDR2 SDRAM should be in all bank precharge with CKE already HIGH prior to writing into the extended
mode register. The mode register set command cycle time (tMRD) must be satisfied to complete the write operation
to the extended mode register. Mode register contents can be changed using the same command and clock cycle
requirements during normal operation as long as all banks are in the precharge state.
DLL enable/disable
The DLL must be enabled for normal operation. DLL enable is required during power-up and initialization, and upon
returning to normal operation after having the DLL disabled. The DLL is automatically disabled when entering self
refresh operation and is automatically re-enabled upon exit of self refresh operation. Any time the DLL is enabled (and
subsequently reset), 200 clock cycles must occur before a Read command can be issued to allow time for the internal
clock to be synchronized with the external clock. Failing to wait for synchronization to occur may result in a violation of
the tAC or tDQSCK parameters.
Integrated Silicon Solution, Inc. — www.issi.com 37
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
Address
Field
Mode
Register
BA2
BA1
0
0
BA0
1
A134
0
A12
Qoff
*1
A11
RDQS
A10
/DQS
A9
A8
OCD
Program
A7
A6
Rtt
A5
A4
Additive
Latency
A3
A2
Rtt
A1
D.I.C
A0
DLL
0
Qoff*3
Output buffer enabled
1
Ouput buffer disabled
A12
A11*1
0
RDQS Enable
A11*1
(RDQS)
(/DQS)
RDQS/DM
/RDQS
DQS
/DQS
0
0
DM
Hi-z
DQS
/DQS
Strobe Function Marix
A10
1
Disable
Enable
A10
/DQS
0
1
DM
Hi-z
DQS
Hi-z
0
Enable
Disable
1
0
RDQS
/RDQS
DQS
/DQS
1
1
RDQS
Hi-z
DQS
Hi-z
1
A9
A8
A7
OCD Calibration Program
0
0
0
OCD Calibration mode exit; maintain setting
0
0
1
0
1
0
Reserved
1
0
0
Reserved
1
1
1
OCD Calibration default*2
A5
A4
A3
Additive Latency
A6
A2
Rtt(NOMINAL)
0
0
0
0
0
0
ODT Disabled
0
0
1
1
0
1
75 ohm
0
1
0
1
0
0
1
1
2
3
1
1
150 ohm
50 ohm
1
0
0
4
DLL enable
Reserved
1
0
1
5
1
1
0
6
1
1
1
Reserved
A1
Output Drive Impedance Control
A0
0
Full Strength
0
Enable
1
Reduced strength
1
Disable
EMR(1)
Notes:
1. x16 doesn't support RDQS option; this must be set to 0 when programming the EMR(1).
2. After setting to default, OCD calibration mode needs to be exited by setting A9-A7 to 000.
3. Output disabled - DQs, DQSs, DQSs, RDQS and RDQS. This feature is used in conjunction with DIMM IDD measurements when IDDQ is not
desired to be included.
4. A13 is only applicable for x8.
38
Integrated Silicon Solution, Inc. — www.issi.com
Rev. B
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IS43/46DR81280C, IS43/46DR16640C
Extended Mode Register 2 (EMR2)
The Extended Mode Register 2 controls refresh related features. The default value of the EMR(2) is not defined,
therefore the mode register must be programmed during initialization for proper operation. The EMR(2) is written
by asserting LOW on CS, RAS, CAS, WE, HIGH on BA1 and LOW on BA0 and BA2, while controlling the states
of address pins A0 - A13. The DDR2 SDRAM should be in all bank precharge state with CKE already HIGH prior
to writing into the EMR(2). The mode register set command cycle time (tMRD) must be satisfied to complete the
write operation to the EMR(2). Mode register contents can be changed using the same command and clock cycle
requirements during normal operation as long as all banks are in the precharge state.
Address
Field
BA2
Mode
Register
0
BA1
1
BA0
0
A13
0
A12*1
0
A11*1
0
A10*1
0
A9*1
0
A8*1
0
*1,3
A7
SRF
A6*1
0
A5*1
0
A4*1
0
A3*1
0
A2*1
0
A1*1
0
A0*1
0
A7
High Temperature Self-Refresh Rate Enable
0
Disable
1
Enable*2
EMR(2)
Notes:
1. A0-A6, A8-A13 are reserved for future use and must be set to 0 when programming the EMR(2).
2. Only Industrial and Automotive grade devices support the high temperature Self-Refresh Mode. The controller can set the EMR (2) [A7] bit to
enable this self-refresh rate if Tc > 85oC while in self-refresh operation. Toper may not be violated.
3. A13 is only applicable for x8.
Integrated Silicon Solution, Inc. — www.issi.com 39
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
DDR2 SDRAM Extended Mode Register 3 (EMR3)
No function is defined in Extended Mode Register (3). The default value of the EMR(3) is not defined, therefore the
EMR(3) must be programmed during initialization for proper operation.
All bits in EMR(3) except BA0, BA1 and BA2 are reserved for future use and must be set to 0 when programming this
mode register.
Address Field
Mode Register
40
BA2 BA1 BA0 A13
0
1
1
0
A12
0
A11 A10
0
0
A9
A8
A7
A6
A5
A4
A3
0
0
0
0
0
0
0
A2 A1 A0
0
0
0
Integrated Silicon Solution, Inc. — www.issi.com
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
Truth tables
Operation or timing that is not specified is illegal, and after such an event, in order to guarantee proper operation,
the DRAM must be powered down and then restarted through the speechified initialization sequence before normal
operation can continue.
Command Truth Table
Function
CKE
CS
RAS
CAS
WE
BA2 BA0
Previous Current
Cycle
Cycle
A13A11
A10
A9-A0
OP Code
Notes
(Extended) Mode
Register Set (Load
Mode)
H
H
L
L
L
L
BA
1, 2
Refresh (REF)
H
H
L
L
L
H
X
X
X
X
Self Refresh Entry
H
L
L
L
L
H
X
X
X
X
1, 8
Self Refresh Exit
L
H
H
X
X
X
X
X
X
X
1, 7, 8
L
H
H
H
1
Single Bank
Precharge
H
H
L
L
H
L
BA
X
L
X
1, 2
Precharge all Banks
H
H
L
L
H
L
X
X
H
X
1
Bank Activate
H
H
L
L
H
H
BA
Write
H
H
L
H
L
L
BA
Write with Auto
Precharge
H
H
L
H
L
L
Read
H
H
L
H
L
Read with AutoPrecharge
H
H
L
H
No Operation
H
X
L
Device Deselect
H
X
Power Down Entry
H
L
Power Down Exit
L
H
Row Address
1,2,10
X
L
Column
1, 2, 3
BA
X
H
Column
1, 2, 3
H
BA
X
L
Column
1, 2, 3
L
H
BA
X
H
Column
1, 2, 3
H
H
H
X
X
X
X
1
H
X
X
X
X
X
X
X
1
H
X
X
X
X
X
X
X
1, 4
L
H
H
H
H
X
X
X
X
X
X
X
1, 4
L
H
H
H
Notes:
1. All DDR2 SDRAM commands are defined by states of CS, RAS, CAS , WE and CKE at the rising edge of the clock.
2. Bank addresses BA0, BA1 and BA2 (BA) determine which bank is to be operated upon. For (E)MRS BA selects an (Extended) Mode Register.
3. Burst reads or writes at BL=4 cannot be terminated or interrupted. See sections "Reads interrupted by a Read" and "Writes interrupted by a
Write" for details.
4. The Power Down Mode does not perform any refresh operations. The duration of Power Down is therefore limited by the refresh requirements
5. The state of ODT does not affect the states described in this table. The ODT function is not available during Self Refresh. See section 3.4.4.
6. “X” means “H or L (but a defined logic level)”
7. Self refresh exit is asynchronous.
8. VREF must be maintained during Self Refresh operation.
9. BAx and Axx refers to the MSBs of bank addresses and addresses, respectively.
10. For x16 option, A13 is "Don't Care" (X) for Activate.
Integrated Silicon Solution, Inc. — www.issi.com 41
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
Clock Enable (CKE) Truth Table
Current
State2
CKE
Command (N)3
Action (N)3
Notes
Previous Cycle
(N-1)
Current Cycle
(N)
L
L
X
Maintain Power-Down
11, 13, 15
L
H
DESELECT or
NOP
Power Down Exit
4, 8, 11, 13
L
L
X
Maintain Self Refresh
11, 15,16
L
H
DESELECT or
NOP
Self Refresh Exit
4, 5, 9, 16
Bank(s)
Active
H
L
DESELECT or
NOP
Active Power Down Entry
4, 8, 10, 11, 13
All Banks
Idle
H
L
DESELECT or
NOP
Precharge Power Down
Entry
4, 8, 10, 11,13
H
L
REFRESH
Self Refresh Entry
H
H
Power Down
Self Refresh
1
1
RAS, CAS, WE,
CS
Refer to the Command Truth Table
6, 9, 11,13
7
Notes:
1. CKE (N) is the logic state of CKE at clock edge N; CKE (N–1) was the state of CKE at the previous clock edge.
2. Current state is the state of the DDR2 SDRAM immediately prior to clock edge N.
3. COMMAND (N) is the command registered at clock edge N, and ACTION (N) is a result of COMMAND (N).
4. All states and sequences not shown are illegal or reserved unless explicitly described elsewhere in this document.
5. On Self Refresh Exit DESELECT or NOP commands must be issued on every clock edge occurring during the tXSNR period. Read commands
may be issued only after tXSRD (200 clocks) is satisfied.
6. Self Refresh mode can only be entered from the All Banks Idle state.
7. Must be a legal command as defined in the Command Truth Table.
8. Valid commands for Power Down Entry and Exit are NOP and DESELECT only.
9. Valid commands for Self Refresh Exit are NOP and DESELECT only.
10. Power Down and Self Refresh cannot be entered while Read or Write operations, (Extended) Mode Register Set operations or Precharge
operations are in progress.
11. tCKEmin of 3 clocks means CKE must be registered on three consecutive positive clock edges. CKE must remain at the valid input level the
entire time it takes to achieve the 3 clocks of registration. Thus, after any CKE transition, CKE may not transition from its valid level during the
time period of tIS + 2 x tCK + tIH.
12. The state of ODT does not affect the states described in this table. The ODT function is not available during Self Refresh.
13. The Power Down does not perform any refresh operations. The duration of Power Down Mode is therefore limited by the refresh requirements
outlined in this datasheet.
14. CKE must be maintained HIGH while the DDRII SDRAM is in OCD calibration mode .
15. “X” means “don’t care (including floating around VREF)” in Self Refresh and Power Down. However ODT must be driven HIGH or LOW in
Power Down if the ODT function is enabled (Bit A2 or A6 set to “1” in EMR(1) ).
16. VREF must be maintained during Self Refresh operation.
Data Mask Truth Table
Name (Functional)
DM
DQs
Note
Write enable
L
Valid
1
Write inhibit
H
X
1
Note:
1. Used to mask write data, provided coincident with the corresponding data
42
Integrated Silicon Solution, Inc. — www.issi.com
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
DESELECT
The DESELECT function (CS HIGH) prevents new commands from being executed by the DDR2 SDRAM. The DDR2
SDRAM is effectively deselected. Operations already in progress are not affected. DESELECT is also referred to as
COMMAND INHIBIT.
NO OPERATION (NOP)
The NO OPERATION (NOP) command is used to instruct the selected DDR2 SDRAM to perform a NOP (CS is LOW;
RAS, CAS, and WE are HIGH). This prevents unwanted commands from being registered during idle or wait states.
Operations already in progress are not affected.
MODE REGISTER SET (MRS or EMRS)
The mode registers are loaded via bank address and address inputs. The bank address balls determine which mode
register will be programmed. See sections on Mode Register and Extended Mode Register. The MRS and EMRS
commands can only be issued when all banks are idle, and a subsequent executable command cannot be issued until
tMRD is met.
ACTIVATE
The ACTIVATE command is used to open (or activate) a row in a particular bank for a subsequent access. The value
on the bank address inputs determines the bank, and the address inputs select the row. This row remains active (or
open) for accesses until a PRECHARGE command is issued to that bank. A PRECHARGE command must be issued
before opening a different row in the same bank.
READ
The READ command is used to initiate a burst read access to an active row. The value on the bank address inputs
determine the bank, and the address provided on address inputs A0–A9 selects the starting column location. The
value on input A10 determines whether or not auto precharge is used. If auto precharge is selected, the row being
accessed will be precharged at the end of the READ burst; if auto precharge is not selected, the row will remain open
for subsequent accesses.
DDR2 SDRAM also supports the AL feature, which allows a READ or WRITE command to be issued prior to tRCD
(MIN) by delaying the actual registration of the READ/WRITE command to the internal device by AL clock cycles.
WRITE
The WRITE command is used to initiate a burst write access to an active row. The value on the bank select inputs
selects the bank, and the address provided on inputs A0–A9 selects the starting column location. The value on input
A10 determines whether or not auto precharge is used. If auto precharge is selected, the row being accessed will be
precharged at the end of the WRITE burst; if auto precharge is not selected, the row will remain open for subsequent
accesses.
DDR2 SDRAM also supports the AL feature, which allows a READ or WRITE command to be issued prior to tRCD
(MIN) by delaying the actual registration of the READ/WRITE command to the internal device by AL clock cycles.
Input data appearing on the DQ is written to the memory array subject to the DM input logic level appearing coincident
with the data. If a given DM signal is registered LOW, the corresponding data will be written to memory; if the DM
signal is registered HIGH, the corresponding data inputs will be ignored, and a WRITE will not be executed to that
byte/column location.
Integrated Silicon Solution, Inc. — www.issi.com 43
Rev. B
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IS43/46DR81280C, IS43/46DR16640C
PRECHARGE
The PRECHARGE command is used to deactivate the open row in a particular bank or the open row in all banks.
The bank(s) will be available for a subsequent row activation a specified time (tRP) after the PRECHARGE command
is issued, except in the case of concurrent auto precharge, where a READ or WRITE command to a different bank
is allowed as long as it does not interrupt the data transfer in the current bank and does not violate any other timing
parameters. After a bank has been precharged, it is in the idle state and must be activated prior to any READ or
WRITE commands being issued to that bank. A PRECHARGE command is allowed if there is no open row in that
bank (idle state) or if the previously open row is already in the process of precharging. However, the precharge period
will be determined by the last PRECHARGE command issued to the bank.
REFRESH
REFRESH is used during normal operation of the DDR2 SDRAM and is analogous to CAS-before-RAS (CBR)
REFRESH. All banks must be in the idle mode prior to issuing a REFRESH command. This command is
nonpersistent, so it must be issued each time a refresh is required. The addressing is generated by the internal refresh
controller. This makes the address bits a “Don’t Care” during a REFRESH command.
Flexibility is provided for the absolute refresh interval. A maximum of 8 Refresh commands can be posted to the
DRAM, meaning that the maximum absolute interval between any Refresh command and the next Refresh command
is 9x tREFI.
SELF REFRESH
The SELF REFRESH command can be used to retain data in the DDR2 SDRAM, even if the rest of the system is
powered down. When in the self refresh mode, the DDR2 SDRAM retains data without external clocking. All power
supply inputs (including VREF) must be maintained at valid levels upon entry/exit and during SELF REFRESH
operation.
The SELF REFRESH command is initiated like a REFRESH command except CKE is LOW. The DLL is automatically
disabled upon entering self refresh and is automatically enabled upon exiting self refresh.
ODT (On-Die Termination)
The On-Die Termination feature allows the DDR2 SDRAM to easily implement a termination resistance (Rtt) for each
DQ, DQS, DQS, RDQS, and RDQS signal. The ODT feature can be configured with the Extended Mode Register Set
(EMRS) command, and turned on or off using the ODT input signal. Before and after the EMRS is issued, the ODT
input must be received with respect to the timings of tAOFD, tMOD(max), tAOND; and the CKE input must be held
HIGH throughout the duration of tMOD(max).
The DDR2 SDRAM supports the ODT on and off functionality in Active, Standby, and Power Down modes, but not in
Self Refresh mode. ODT timing diagrams follow for Active/Standby mode and Power Down mode.
EMRS to ODT Update Delay
CMD
E MRS
NOP
NOP
NOP
NOP
NOP
CK
CK
ODT
tIS
tAOFD
Rtt
44
Old setting
tMOD,max
tMOD,min
tAOND
ODT Ready
Updated
Integrated Silicon Solution, Inc. — www.issi.com
Rev. B
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IS43/46DR81280C, IS43/46DR16640C
ODT On/Off Timing for Active/Standby mode
T0
T1
T2
T3
T4
T5
T6
CK
CK
tIS
CKE
tIS
tIS
VIH(ac)
ODT
VIL(ac)
tAOFD
tAOND
Valid
Rtt
tAOF,min
tAON,max
tAON,min
tAOF,max
ODT On/Off Timing for Power-Down mode
T0
T1
T2
T3
T4
T5
T6
CK
CK
CKE
ODT
tIS
tIS
VIH(ac)
VIL(ac)
tAOFPD,max
tAOFPD,min
Rtt
tAONPD,min
tAONPD,max
Valid
Integrated Silicon Solution, Inc. — www.issi.com 45
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
Ordering Information: x8
Commercial Range: Tc = 0°C to +85°C
Clock (MHz) Speed Grade
CL-tRCD-tRP
Order Part No.
Package
400
DDR2-800D
5-5-5
IS43DR81280C-25DBL
60 Ball BGA, Lead-free
333
DDR2-667D
5-5-5
IS43DR81280C-3DBL
60 Ball BGA, Lead-free
Industrial Range: Tc = -40°C to +95°C, Ta = -40°C to +85°C
Clock (MHz) Speed Grade
CL-tRCD-tRP
Order Part No.
Package
400
DDR2-800D
5-5-5
IS43DR81280C-25DBLI
60 Ball BGA, Lead-free
333
DDR2-667D
5-5-5
IS43DR81280C-3DBLI
60 Ball BGA, Lead-free
Automotive Range, A1: Tc = -40°C to +95°C, Ta = -40°C to +85°C
Clock (MHz) Speed Grade
CL-tRCD-tRP
Order Part No.
Package
400
DDR2-800D
5-5-5
IS46DR81280C-25DBLA1
60 Ball BGA, Lead-free
333
DDR2-667D
5-5-5
IS46DR81280C-3DBLA1
60 Ball BGA, Lead-free
Automotive Range, A2: Tc = -40°C to +105°C, Ta = -40°C to +105°C
Clock (MHz) Speed Grade
CL-tRCD-tRP
Order Part No.
Package
400
DDR2-800D
5-5-5
IS46DR81280C-25DBLA2
60 Ball BGA, Lead-free
333
DDR2-667D
5-5-5
IS46DR81280C-3DBLA2
60 Ball BGA, Lead-free
Notes:
1. Please contact ISSI for availability of leaded options.
2. The -3D, and -25D speed options are backward compatible with all the timing specifications for slower grades.
46
Integrated Silicon Solution, Inc. — www.issi.com
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
Ordering Information: x16
Commercial Range: Tc = 0°C to +85°C
Clock (MHz) Speed Grade
CL-tRCD-tRP
Order Part No.
Package
400
DDR2-800D
5-5-5
IS43DR16640C-25DBL
84 Ball BGA, Lead-free
333
DDR2-667D
5-5-5
IS43DR16640C-3DBL
84 Ball BGA, Lead-free
Industrial Range: Tc = -40°C to +95°C, Ta = -40°C to +85°C
Clock (MHz) Speed Grade
CL-tRCD-tRP
Order Part No.
Package
400
DDR2-800D
5-5-5
IS43DR16640C-25DBLI
84 Ball BGA, Lead-free
333
DDR2-667D
5-5-5
IS43DR16640C-3DBLI
84 Ball BGA, Lead-free
Automotive Range, A1: Tc = -40°C to +95°C, Ta = -40°C to +85°C
Clock (MHz) Speed Grade
CL-tRCD-tRP
Order Part No.
Package
400
DDR2-800D
5-5-5
IS46DR16640C-25DBLA1
84 Ball BGA, Lead-free
333
DDR2-667D
5-5-5
IS46DR16640C-3DBLA1
84 Ball BGA, Lead-free
Automotive Range, A2: Tc = -40°C to +105°C, Ta = -40°C to +105°C
Clock (MHz) Speed Grade
CL-tRCD-tRP
Order Part No.
Package
400
DDR2-800D
5-5-5
IS46DR16640C-25DBLA2
84 Ball BGA, Lead-free
333
DDR2-667D
5-5-5
IS46DR16640C-3DBLA2
84 Ball BGA, Lead-free
Notes:
1. Please contact ISSI for availability of leaded options.
2. The -3D, and -25D speed options are backward compatible with all the timing specifications for slower grades.
Integrated Silicon Solution, Inc. — www.issi.com 47
Rev. B
12/6/2017
IS43/46DR81280C, IS43/46DR16640C
48
Integrated Silicon Solution, Inc. — www.issi.com
Rev. B
12/6/2017
Package Outline
11/11/2008
IS43/46DR81280C, IS43/46DR16640C
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