SAMSUNG K4N56163QF-GC30

256M gDDR2 SDRAM
K4N56163QF-GC
256Mbit gDDR2 SDRAM
Revision 1.6
April 2005
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AND IS SUBJECT TO CHANGE WITHOUT NOTICE.
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ON AS "AS IS" BASIS WITHOUT GUARANTEE OR WARRANTY OF ANY KIND.
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Samsung Electronics reserves the right to change products or specification without notice.
- 1 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Revision History
Revision 1.6 (April 14, 2005)
• Modified Power-up and Initialization Sequence on page 22.
Revision 1.5 (March 04, 2005)
• Removed K4N56163QF-GC20/22 from the datasheet
Revision 1.4 (February 5, 2005)
• Added Lead-Free part number in the datasheet.
Revision 1.3 (January 5, 2005)
• Typo corrected
Revision 1.2 (December 28, 2004)
• Changed the DC characteristics table
• Added 50 ohm at the EMRS(1) programming table.
Revision 1.1 (December 1, 2004)
• Changed ICC2P and ICC6 to 10mA
Revision 1.0 (October 20, 2004)
• DC spec defined.
• Changed VDD&VDDQ of K4N56163QF-GC20/22 from 1.8V+0.1V to 2.0V+0.1V
Revision 0.0 (April 29, 2004) - Target Spec
• Defined Target Specification
- 2 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
4M x 16Bit x 4 Banks graphic DDR2 Synchronous DRAM
with Differential Data Strobe
FEATURES
• 1.8V + 0.1V power supply for device operation
• 1.8V + 0.1V power supply for I/O interface
• Bi-directional Differential Data-Strobe
(Single-ended data-strobe is an optional feature)
• 4 Banks operation
• Off-chip Driver (OCD) Impedance Adjustment
• Posted CAS
• On Die Termination
• Programmable CAS Letency : 4, 5, 6 and 7
• Refresh and Self Refresh
• Programmable Additive Latency : 0, 1, 2, 3, 4 and 5
Average Refesh Period 7.8us at lower then TCASE 85×C,
• Write Latency (WL) = Read Latency (RL) -1
3.9us at 85×C < TCASE < 95 ×C
• Burst Legth : 4 and 8 (Interleave/nibble sequential)
• 84 ball FBGA
• Programmable Sequential/ Interleave Burst Mode
ORDERING INFORMATION
Part NO.
Max Freq.
Max Data Rate
K4N56163QF-GC25
400MHz
800Mbps/pin
K4N56163QF-GC30
333MHz
667Mbps/pin
K4N56163QF-GC37
266MHz
533Mbps/pin
Interface
Package
SSTL
84 Ball FBGA
* K4N56163QF-ZC is the Lead-Free part number.
GENERAL DESCRIPTION
FOR 4M x 16Bit x 4 Bank gDDR2 SDRAM
The 256Mb gDDR2 SDRAM chip is organized as 4Mbit x 16 I/O x 4banks banks device. This synchronous device
achieve high speed graphic double-data-rate transfer rates of up to 1000Mb/sec/pin for general applications. The chip is
designed to comply with the following key gDDR2 SDRAM features such as posted CAS with additive latency, write latency
= read latency - 1, Off-Chip Driver(OCD) impedance adjustment and On Die Termination.
All of the control and address inputs are synchronized with a pair of externally supplied differential clocks. Inputs are
latched at the cross point of differential clocks (CK rising and CK falling). All I/Os are synchronized with a pair of bidirectional strobes (DQS and DQS) in a source synchronous fashion. A thirteen bit address bus is used to convey row, column,
and bank address information in a RAS/CAS multiplexing style. For example, 256Mb(x16) device receive 13/9/2 addressing. The 256Mb gDDR2 devices operate with a single 1.8V ± 0.1V power supply and 1.8V ± 0.1V VDDQ.
The 256Mb gDDR2 devices are available in 84ball FBGAs(x16).
Note : The functionality described and the timing specifications included in this data sheet are for the DLL Enabled mode of
operation.
- 3 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
PIN CONFIGURATION
Normal Package (Top View)
1
2
3
7
8
VDD
NC
VSS
UDQ6
VSSQ
VDDQ
UDQ4
A
VSSQ
UDQS
UDM
B
UDQS
VSSQ
UDQ7
UDQ1
VDDQ
C
VDDQ
UDQ0
VDDQ
VSSQ
UDQ3
D
UDQ2
VSSQ
UDQ5
NC
VSS
E
VSSQ
LDQS
VDDQ
LDQ6
VSSQ
LDM
F
LDQS
VSSQ
LDQ7
VDDQ
LDQ1
VDDQ
G
VDDQ
LDQ0
VDDQ
LDQ4
VSSQ
LDQ3
H
LDQ2
VSSQ
LDQ5
VDDL
VREF
VSS
J
VSSDL
CK
VDD
CKE
WE
K
RAS
CK
ODT
BA0
BA1
L
CAS
CS
A10
A1
M
A2
A0
A3
A5
N
A6
A4
A7
A9
P
A11
A8
A12
NC
R
NC
NC
VDD
NC
VSS
VDD
9
VDDQ
VDD
VSS
Notes:
VDDL and VSSDL are power and ground for the DLL. lt is recommended that they are isolated on the device from VDD,
VDDQ, VSS, and VSSQ.
1
Ball Locations
2
A
B
C
: Populated Ball
+ : Depopulated Ball
D
E
F
Top View
(See the balls through the Package)
G
H
J
K
+
L
M
+
N
P
+
R
- 4 -
3
4
5
6
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
7
8
9
+
+
+
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
PACKAGE DIMENSIONS (84 Ball FBGA)
11.00 ± 0.10
# A1 INDEX MARK (OPTIONAL)
6.40
0.80
9
8
7
1.60
6
5
4
3
2
1
A
B
C
D
E
11.20
H
0.80
M
J
K
5.60
N
13.00 ± 0.10
F
G
1.60
L
P
R
3.20
∅0.2 M A B
(6.15)
(0.90)
(1.80)
0.10MAX
84-∅0.45±0.05
11.00 ± 0.10
0.50±0.05
13.00 ± 0.10
#A1
0.35±0.05
MAX.1.20
Unit : mm
- 5 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
INPUT/OUTPUT FUNCTIONAL DESCRIPTION
Symbol
Type
Function
Input
Clock: CK and CK are differential clock inputs. CMD, ADD inputs 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. CKE must be maintained high throughout read and write accesses. Input buffers, excluding CK, CK 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 bank
selection on systems with multiple banks. CS is considered part of the command code.
ODT
Input
On Die Termination: ODT (registered HIGH) enables termination resistance internal to the gDDR2
SDRAM. When enabled, ODT is only applied to each DQ, UDQS/UDQS, LDQS/LDQS, UDM, and LDM
signal for x16 configurations. The ODT pin will be ignored if the Extended Mode Register (EMRS) is programmed to disable ODT.
RAS, CAS, WE
Input
Command Inputs: RAS, CAS and WE (along with CS) define the command being entered.
(L)UDM
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.
BA0 - BA1
Input
Bank Address Inputs: BA0 and BA1 define to which bank an Actove, Read, Write or Precharge command is being applied. BA0 also determines if the mode register or extended mode register is to be
accessed during a MRS or EMRS cycle.
Input
Address Inputs: Provided the row address for Active commands and the column address and Auto Precharge bit for Read/Write commands to select one location out of the memory array in the respective
bank. A10 is sampled during a Precharge command to determine whether the Precharge applies to one
bank (A10 LOW) or all banks (A10 HIGH). If only one bank is to be precharged, the bank is selected by
BA0, BA1. The address inputs also provide the op-code during Mode Register Set commands.
CK, CK
A0 - A12
DQ
LDQS,(LDQS)
UDQS,(UDQS)
NC/RFU
Input/ Data Input/ Output: Bi-directional data bus.
Output
Data Strobe: output with read data, input with write data. Edge-aligned with read data, centered in write
data. LDQS corresponds to the data on DQ0-DQ7; UDQS corresponds to the data on DQ8-DQ15. The
Input/ data strobes LDQS and UDQS may be used in single ended mode or paired with optional complementary
Output
signals LDQS and UDQS to provide differential pair signaling to the system during both reads and writes.
An EMRS(1) control bit enables or disables all complementary data strobe signals.
No Connect: No internal electrical connection is present.
VDDQ
Supply DQ Power Supply: 1.8V ± 0.1V
VSSQ
Supply DQ Ground
VDDL
Supply DLL Power Supply: 1.8V ± 0.1V
VSSL
Supply DLL Ground
VDD
Supply Power Supply: 1.8V ± 0.1V
VSS
Supply Ground
VREF
Supply Reference voltage
- 6 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Absolute Maximum DC Ratings
1.
Symbol
Parameter
Rating
Units
Notes
VDD
Voltage on VDD pin relative to Vss
- 1.0 V ~ 2.3 V
V
1
VDDQ
Voltage on VDDQ pin relative to Vss
- 0.5 V ~ 2.3 V
V
1
VDDL
Voltage on VDDL pin relative to Vss
- 0.5 V ~ 2.3 V
V
1
VIN, VOUT
Voltage on any pin relative to Vss
- 0.5 V ~ 2.3 V
V
1
TSTG
Storage Temperature
-55 to +100
°C
1, 2
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.
AC & DC Operating Conditions
Recommended DC Operating Conditions (SSTL - 1.8)
Rating
Symbol
Parameter
Units
Min.
Typ.
Max.
Notes
VDD
Supply Voltage
1.7
1.8
1.9
V
VDDL
Supply Voltage for DLL
1.7
1.8
1.9
V
4
VDDQ
Supply Voltage for Output
1.7
1.8
1.9
V
4
VREF
Input Reference Voltage
0.49*VDDQ
0.50*VDDQ
0.51*VDDQ
mV
1,2
Termination Voltage
VREF-0.04
VREF
VREF+0.04
V
3
VTT
There is no specific device VDD supply voltage requirement for SSTL-1.8 compliance. However under all conditions VDDQ must
be less than or equal to VDD.
1. 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.
2. Peak to peak AC noise on VREF may not exceed +/-2% VREF(DC).
3. VTT of transmitting device must track VREF of receiving device.
4. AC parameters are measured with VDD, VDDQ and VDDDL tied together.
- 7 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Operating Temperature Condition
Symbol
Parameter
Rating
Units
Notes
TOPER
Operating Temperature
0 to 95
°C
1, 2, 3
1. Operating Temperature is the case surface temperature on the center/top side of the DRAM. For the measurement conditions,
please refer to JESD51.2 standard.
2. At 0 - 85 °C, operation temperature range are the temperature which all DRAM specification will be supported.
3. At 85 - 95 °C operation temperature range, doubling refresh commands in frequency to a 32ms period ( tREFI=3.9 us ) is required,
and to enter to self refresh mode at this temperature range, an EMRS command is required to change internal refresh rate.
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
Parameter
Min.
Max.
Units
VIH(AC)
Symbol
AC input logic high
VREF + 0.250
-
V
VIL(AC)
AC input logic low
-
VREF - 0.250
V
Notes
AC Input Test Conditions
Symbol
Condition
Value
Units
Notes
VREF
Input reference voltage
0.5 * VDDQ
V
1
VSWING(MAX)
Input signal maximum peak to peak swing
1.0
V
1
SLEW
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.
VDDQ
VIH(AC) min
VIH(DC) min
VSWING(MAX)
VREF
VIL(DC) max
VIL(AC) max
delta TF
Falling Slew =
delta TR
VREF - VIL(AC) max
Rising Slew =
delta TF
VSS
VIH(AC) min - VREF
delta TR
< AC Input Test Signal Waveform >
- 8 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Differential input AC logic Level
Symbol
Parameter
Min.
Max.
Units
Notes
VID(AC)
AC differential input voltage
0.5
VDDQ + 0.6
V
1
VIX(AC)
AC differential cross point voltage
0.5 * VDDQ - 0.175
0.5 * 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, LDQS or UDQS) and VCP is the complementary input signal (such as CK, DQS, LDQS or UDQS).
The minimum value is equal to VIH(AC) - VIL(AC).
2. The typical value of VIX(AC) is expected to be about 0.5 * 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.
VDDQ
VTR
Crossing point
VID
VIX or VOX
VCP
VSSQ
< Differential signal levels >
Differential AC output parameters
Symbol
VOX(AC)
Parameter
AC differential cross point voltage
Min.
Max.
Units
Note
0.5 * VDDQ - 0.125
0.5 * VDDQ + 0.125
V
1
Note :
1. The typical value of VOX(AC) is expected to be about 0.5 * 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.
- 9 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
OCD default characteristics
Description
Parameter
Min
Nom
Output impedance
12.6
Output impedance step size for
OCD calibration
Pull-up and pull-down mismatch
Output slew rate
Sout
18
Max
Unit
Notes
23.4
ohms
1,2
0
1.5
ohms
6
0
4
ohms
1,2,3
1.5
5
V/ns
1,4,5,6,7,8
Notes:
1. Absolute Specifications (0°C ≤ TCASE ≤ +95°C; VDD = +1.8V ±0.1V, VDDQ = +1.8V ±0.1V)
2. Impedance measurement condition for output source dc current: VDDQ = 1.7V; VOUT = 1420mV;
(VOUT-VDDQ)/Ioh must be
less than 23.4 ohms for values of VOUT between VDDQ and VDDQ280mV. Impedance measurement condition for output sink dc current: VDDQ = 1.7V; VOUT = 280mV; VOUT/Iol must be less than
23.4 ohms for values of VOUT between 0V and 280mV.
3. Mismatch is absolute value between pull-up and pull-dn, 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 ohms at nominal conditions across all process and represents only the
DRAM uncertainty.
Output slew rate load :
VTT
25 ohms
Output
(VOUT)
Reference
Point
7. DRAM output slew rate specification applies to 533Mb/sec/pin, 667Mb/sec/pin, 800Mb/sec/pin, 900Mbps/sec/pin and
1000Mbps/sec/pin speed bins.
8. Timing skew due to DRAM output slew rate mis-match between DQS / DQS and associated DQs is included in tDQSQ and tQHS
specification.
- 10 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
DC CHARACTERISTICS
(Recommended operating conditions unless otherwise noted, 0°C ≤ Tc ≤85°C )
Version
Parameter
Symbol
Test Condition
Unit
- 25
- 30
- 37
150
135
120
Operating Current
(One Bank Active)
ICC1
Burst Length=4 tRC ≥ tRC(min). IOL=0mA, tCC= tCC(min).
DQ,DM,DQS inputs changing twice per clock cycle.
Address and control inputs changing once per clock
cycle
Precharge Standby Current
in Power-down mode
ICC2P
CKE ≤ VIL(max), tCC= tCC(min)
Precharge Standby Current
in Non Power-down mode
ICC2N
CKE ≥ VIH(min), CS ≥ VIH(min),tCC= tCC(min)
Address and control inputs changing once per clock
cycle
45
45
40
mA
Active Standby Current
power-down mode
ICC3P
CKE ≤ VIL(max), tCC= tCC(min)
50
50
50
mA
Active Standby Current in
in Non Power-down mode
ICC3N
CKE ≥ VIH(min), CS ≥ VIH(min), tCC= tCC(min)
DQ,DM,DQS inputs changing twice per clock cycle.
Address and control inputs changing once per clock
cycle
85
85
80
mA
Operating Current
( Burst Mode)
ICC4
IOL=0mA ,tCC= tCC(min),
Page Burst, All Banks activated. DQ,DM,DQS inputs
changing twice per clock cycle. Address and control
inputs changing once per clock.
300
280
260
mA
Refresh Current
ICC5
tRC≥ tRFC
190
180
160
mA
Self Refresh Current
ICC6
CKE ≤ 0.2V
Operating Current
(4Bank interleaving)
ICC7
Burst Length=4 tRC ≥ tRC(min). IOL=0mA, tCC= tCC(min).
DQ,DM,DQS inputs changing twice per clock cycle.
Address and control inputs changing once per clock
cycle
10
mA
10
430
400
mA
mA
350
mA
Note : 1. Measured with outputs open and ODT off
2. Refresh period is 32ms
- 11 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Input/Output capacitance
- 30
- 25
- 37
Parameter
Symbol
Min
Max
Min
Max
Units
1.0
2.0
1.0
2.0
pF
x
0.25
x
0.25
pF
1.0
2.0
1.0
2.0
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
x
0.25
x
0.25
pF
Input/output capacitance, DQ, DM, DQS, DQS
CIO
2.5
4.0
2.5
3.5
pF
Input/output capacitance delta, DQ, DM, DQS, DQS
CDIO
x
0.5
x
0.5
pF
Electrical Characteristics & AC Timing for - 35/30/37
(0 °C < TCASE < 95 °C; VDDQ = 1.8V + 0.1V; VDD = 1.8V + 0.1V)
Refresh Parameters by Device Density
Parameter
Symbol
Refresh to active/Refresh command time
tRFC
Average periodic refresh interval
tREFI
256Mb
Units
75
ns
0 °C ≤ TCASE ≤ 85°C
7.8
µs
85 °C < TCASE ≤ 95°C
3.9
µs
Speed Bins and CL, tRCD, tRP, tRC and tRAS
SPEED
- 25
- 30
- 37
Bin (CL-tRCD-tRP)
6-6-6
5-5-5
4-5-5
Parameter
min
min
min
6
5
4
tCK
2.5
3.0
3.75
ns
tRCD
6
5
5
tCK
tRP
6
5
5
tCK
tRC
22
18
16
tCK
tRAS
16
13
11
tCK
CAS LATENCY
tCK
- 12 -
Units
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Timing Parameters by Speed Grade
(Refer to notes for informations related to this table at the bottom)
- 25
Parameter
- 30
- 37
Symbol
Units
min
max
min
DQ output access time from CK/CK
tAC
-400
400
-450
DQS output access time from CK/CK
tDQSCK
-350
+350
-400
CK high-level width
tCH
0.45
0.55
CK low-level width
tCL
0.45
CK half period
tHP
Clock cycle time, CL=x
max
Notes
max
-500
+500
ps
+400
-450
+450
ps
0.45
0.55
0.45
0.55
tCK
0.55
0.45
0.55
0.45
0.55
tCK
min
(tCL, tCH)
x
min
(tCL, tCH)
x
min
(tCL, tCH)
x
ps
20,21
tCK
2.5
8.0
3.0
8.0
3.75
8.0
ns
24
DQ and DM input hold time
tDH
175
x
175
x
225
x
ps
15,16,17
DQ and DM input setup time
tDS
50
x
50
x
100
x
ps
15,16,17
Control & Address input pulse width
for each input
tIPW
0.6
x
0.6
x
0.6
x
tCK
DQ and DM input pulse width for
each input
tDIPW
0.35
x
0.35
x
0.35
x
tCK
Data-out high-impedance time from
CK/CK
tHZ
x
tAC max
x
tAC max
x
tAC max
ps
DQS low-impedance time from CK/
CK
tLZ
(DQS)
tAC min
tAC max
tAC min
tAC max
tAC min
tAC max
ps
27
DQ low-impedance time from CK/CK
tLZ(DQ)
2*tAC min
tAC max
2*tAC min
tAC max
2* tACmin
tAC max
ps
27
DQS-DQ skew for DQS and
associated DQ signals
tDQSQ
x
280
x
310
x
340
ps
22
DQ hold skew factor
tQHS
x
380
x
410
x
440
ps
21
DQ/DQS output hold time from DQS
tQH
tHP tQHS
x
tHP tQHS
x
tHP tQHS
x
ps
Write command to first DQS latching
transition
tDQSS
WL
-0.25
WL
+0.25
WL
-0.25
WL
+0.25
WL
-0.25
WL
+0.25
tCK
DQS input high pulse width
tDQSH
0.35
x
0.35
x
0.35
x
tCK
DQS input low pulse width
tDQSL
0.35
x
0.35
x
0.35
x
tCK
DQS falling edge to CK setup time
tDSS
0.2
x
0.2
x
0.2
x
tCK
DQS falling edge hold time from CK
tDSH
0.2
x
0.2
x
0.2
x
tCK
Mode register set command cycle
time
tMRD
2
x
2
x
2
x
tCK
Write postamble
tWPST
0.4
0.6
0.4
0.6
0.4
0.6
tCK
Write preamble
tWPRE
0.35
x
0.35
x
x
tCK
- 13 -
+450
min
0.35
19
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
- 25
Parameter
- 30
- 37
Symbol
Units
min
max
min
max
min
max
Notes
Address and control input hold time
tIH
475
x
475
x
475
x
ps
14,16,18
Address and control input setup time
tIS
350
x
350
x
350
x
ps
14,16,18
Read preamble
tRPRE
0.9
1.1
0.9
1.1
0.9
1.1
tCK
28
Read postamble
tRPST
0.4
0.6
0.4
0.6
0.4
0.6
tCK
28
Active to active command period for
1KB page size products
tRRD
7.5
x
7.5
x
7.5
x
ns
12
Active to active command period for
2KB page size products
tRRD
10
x
10
x
10
x
ns
12
Four Activate Window for 1KB page
size products
tFAW
37.5
37.5
37.5
ns
Four Activate Window for 2KB page
size products
tFAW
50
50
50
ns
CAS to CAS command delay
tCCD
2
2
2
tCK
Write recovery time
tWR
6
x
5
x
4
x
tCK
Auto precharge write recovery +
precharge time
tDAL
tWR
+tRP
x
tWR
+tRP
x
tWR
+tRP
x
tCK
Internal write to read command delay
tWTR
3
x
3
x
2
x
tCK
Internal read to precharge command
delay
tRTP
3
3
2
tCK
Exit self refresh to a non-read
command
tXSNR
tRFC + 10
tRFC + 10
tRFC +
10
ns
Exit self refresh to a read command
tXSRD
200
200
200
tCK
Exit precharge power down to any
non-read command
tXP
2
x
2
x
2
x
tCK
Exit active power down to read
command
tXARD
2
x
2
x
2
x
tCK
9
Exit active power down to read
command
(Slow exit, Lower power)
tXARDS
tCK
9, 10
CKE minimum pulse width
(high and low pulse width)
6-AL
6 - AL
6 - AL
tCKE
3
3
3
ODT turn-on delay
tAOND
3
3
2
2
2
2
tCK
ODT turn-on
tAON
tAC
(min)
tAC
(max)+0.7
tAC
(min)
tAC
(max)+0.7
tAC
(min)
tAC
(max)+1
ns
ODT turn-on(Power-Down mode)
tAONPD
tAC
(min)
+2
3tCK+
tAC(max)
+1
tAC
(min)+2
2tCK+
tAC(max)
+1
tAC
(min)+2
2tCK+tA
C(max)+1
ns
ODT turn-off delay
tAOFD
3.5
3.5
2.5
2.5
2.5
2.5
tCK
- 14 -
23
11
tCK
13, 25
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
- 25
Parameter
- 30
- 37
Symbol
Units
Notes
tAC
(max)+ 0.6
ns
26
2.5tCK+
tAC(max)+
1
ns
min
max
min
max
min
max
tAC
(min)
tAC
(max)+ 0.6
tAC
(min)
tAC
(max)+ 0.6
tAC
(min)
tAC(min)+2
3.5tCK+tA
C(max)+1
tAC(min)+2
2.5tCK+tA
C(max)+1
tAC(min)+
2
ODT turn-off
tAOF
ODT turn-off (Power-Down
mode)
tAOFPD
ODT to power down entry
latency
tANPD
3
3
3
tCK
ODT power down exit latency
tAXPD
8
8
8
tCK
OCD drive mode output delay
tOIT
0
Minimum time clocks remains
ON after CKE
asynchronously drops LOW
tDelay
12
0
tIS+tCK
+tIH
12
0
tIS+tCK
+tIH
tIS+tCK
+tIH
12
ns
ns
24
General notes, which may apply for all AC parameters
1. 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 = +500mV. 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 dc-level to ac-level: from VREF - 125 mV to VREF + 250 mV for rising
edges and from VREF + 125 mV and VREF - 250 mV 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
(250mV to -500 mV for falling egdes).
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.
2. gDDR2 SDRAM AC timing reference load
Following figure 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
will correlate to their production test conditions (generally a coaxial transmission line terminated at the tester electronics).
VDDQ
DUT
DQ
DQS
DQS
Output
VTT = VDDQ/2
Timing
reference
point
25Ω
<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.
- 15 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
3. gDDR2 SDRAM output slew rate test load
Output slew rate is characterized under the test conditions as shown in the following figure.
VDDQ
DUT
DQ
DQS, DQS
Output
VTT = VDDQ/2
25Ω
Test point
<Slew Rate Test Load>
4. Differential data strobe
gDDR2 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 gDDR2 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 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 ohm to 10 K ohm
resisor to insure proper operation.
tDQSH
DQS
DQS/
DQS
tDQSL
DQS
tWPRE
tWPST
VIH(dc)
VIH(ac)
DQ
D
D
VIL(dc)
VIL(ac)
tDS
tDS
VIH(ac)
DM
D
D
DMin
DMin
tDH
tDH
VIH(dc)
DMin
DMin
VIL(ac)
VIL(dc)
<Data input (write) timing>
tCH
tCL
CK
CK/CK
CK
DQS
DQS/DQS
DQS
tRPST
tRPRE
DQ
Q
Q
tDQSQmax
Q
Q
tDQSQmax
tQH
tQH
<Data output (read) timing>
5. AC timings are for linear signal transitions.
6. These parameters guarantee device behavior, but they are not necessarily tested on each device.
They may be guaranteed by device design or tester correlation.
- 16 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
7. All voltages are referenced to VSS.
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
9. User can choose which active power down exit timing to use via MRS(bit 12). 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.
10. AL = Additive Latency
11. This is a minimum requirement. Minimum read to precharge timing is AL + BL/2 providing the tRTP and tRAS(min) have been
satisfied.
12. A minimum of two clocks (2 * tCK) is required irrespective of operating frequency
13. Timings are guaranteed with command/address input slew rate of 1.0 V/ns.
14. These parameters guarantee device behavior, but they are not necessarily tested on each device. They may be guaranteed by
device design or tester correlation.
15. Timings are guaranteed with data, mask, and (DQS in singled ended mode) input slew rate of 1.0 V/ns.
16. Timings are guaranteed 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 1V/ns in single ended mode.
17. tDS and tDH (data setup and hold) derating
1) 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.
2) Input waveform timing is referenced from the input signal crossing at the VIH(DC) level for a rising signal and VIL(DC) for a
falling signal applied to the device under test.
DQS
DQS
tDS
tDH
tDS
tDH
VDDQ
VIH(AC) min
VIH(DC) min
VREF
VIL(DC) max
VIL(AC) max
VSS
<Data setup/hold timing>
- 17 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
18. tIS and tIH (input setup and hold) derating
1) 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.
2) Input waveform timing is referenced from the input signal crossing at the VIH(DC) level for a rising
signal and VIL(DC) for a falling signal applied to the device under test
CK
CK
tIS
tIH
tIS
tIH
VDDQ
VIH(AC) min
VIH(DC) min
VREF
VIL(DC) max
VIL(AC) max
VSS
<Input setup/hold timing>
19. 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.
20. 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.
21. tQH = tHP – tQHS, where:
tHP = 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.
22. 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.
23. tDAL = (nWR) + ( tRP/tCK):
For each of the terms above, if not already an integer, round to the next highest integer. tCK refers to the application clock period. nWR
refers to the tWR parameter stored in the MRS.
Example: For gDDR533 at t CK = 3.75 ns with tWR programmed to 4 clocks. tDAL = 4 + (15 ns / 3.75 ns) clocks =4 +(4)clocks=8clocks.
- 18 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
24. 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 gDDR2 device operation
25. 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.
26. 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.
27. 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) . Following figure shows a method to
calculate the point when device is no longer driving (tHZ), or begins driving (tLZ) by measuring the signal at two different voltages. The
actual voltage measurement points are not critical as long as the calculation is consistent.
28. 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). Following figure shows a method to calculate these points when the device is no
longer driving (tRPST), or begins driving (tRPRE) by measuring the signal at two different voltages. The actual voltage measurement
points are not critical as long as the calculation is consistent.
These notes are referenced to the “Timing parameters by speed grade” tables for gDDR2-533/667 and gDDR2-800.
VOH + x mV
VTT + 2x mV
VOH + 2x mV
VTT + x mV
tLZ
tHZ
tRPRE begin point
tRPST end point
T2
VOL + 2x mV
VTT - x mV
VOL + x mV
VTT - 2x mV
T1
T2
T1
tHZ,tRPST end point = 2*T1-T2
tLZ,tRPRE begin point = 2*T1-T2
<Test method for tLZ, tHZ, tRPRE and tRPST>
- 19 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
gDDR2 SDRAM
Device Operation & Timing Diagram
- 20 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Functional Description
Simplified State Diagram
Initialization
Sequence
CKEL
OCD
calibration
Self
Refreshing
SRF
CKEH
PR
Setting
MRS
EMRS
Idle
MRS
REF
All banks
precharged
Refreshing
CKEL
ACT
CKEL
CKEH
Precharge
Power
Down
Activating
CKEL
CKEL
CKEL
Automatic Sequence
Active
Power
Down
Command Sequence
CKEH
CKEL
Bank
Active
Read
Write
Write
Read
WRA
Writing
RDA
Read
Reading
RDA
WRA
RDA
Writing
with
Autoprecharge
PR, PRA
PR, PRA
PR, PRA
Precharging
Reading
with
Autoprecharge
CKEL = CKE low, enter Power Down
CKEH = CKE high, exit Power Down, exit Self Refresh
ACT = Activate
WR(A) = Write (with Autoprecharge)
RD(A) = Read (with Autoprecharge)
PR(A) = Precharge (All)
MRS = (Extended) Mode Register Set
SRF = Enter Self Refresh
REF = Refresh
Note: Use caution with this diagram. It is indented to provide a floorplan of the possible state transitions
and the commands to control them, not all details. In particular situations involving more than one bank,
enabling/disabling on-die termination, Power Down entry/exit - among other things - are not captured
in full detail.
- 21 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Basic Functionality
Read and write accesses to the gDDR2 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, BA1 select the bank; A0-A12 select the row). The address bits registered coincident with the Read or Write command are used to select the starting column location for the burst access
and to determine if the auto precharge command is to be issued.
Prior to normal operation, the gDDR2 SDRAM must be initialized. The following sections provide detailed information covering device initialization, register definition, command descriptions and device operation.
Power up and Initialization
gDDR2 SDRAMs must be powered up and initialized in a predefined manner. Operational procedures other than those
specified may result in undefined operation.
Power-up and Initialization Sequence
The following sequence is required for POWER UP and Initialization.
1. Apply power and attempt to maintain CKE below 0.2*VDDQ and ODT*1 at a low state (all other inputs may be undefined.) The power voltage ramps are without any slope reversal, ramp time must be no greater than 20mS; and during
the ramp, VDD>VDDL>VDDQ and VDD-VDDQ<0.3 volts.
- VDD, VDDL and VDDQ are driven from a single power converter output, AND
- VTT is limited to 0.95 V max, AND
- Vref tracks VDDQ/2.
or
- Apply VDD before or at the same time as VDDL.
- Apply VDDL before or at the same time as VDDQ.
- Apply VDDQ before or at the same time as VTT & VREF.
at least one of these two sets of conditions must be met.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Start clock and maintain stable condition.
For the minimum of 200µs after stable power and clock(CK, CK), then apply NOP or deselect & take CKE high.
Wait minimum of 400ns then issue precharge all command. NOP or deselect applied during 400ns period.
Issue EMRS(2) command. (To issue EMRS(2) command, provide “Low” to BA0, “High” to BA1.)
Issue EMRS(3) command. (To issue EMRS(3) command, provide “High” to BA0 and BA1.)
Issue EMRS to enable DLL. (To issue "DLL Enable" command, provide "Low" to A0, "High" to BA0 and "Low" to BA1
and A12.)
Issue a Mode Register Set command for “DLL reset”.
(To issue DLL reset command, provide "High" to A8 and "Low" to BA0-1)
Issue precharge all command.
Issue 2 or more auto-refresh commands.
Issue a mode register set command with low to A8 to initialize device operation. (i.e. to program operating parameters
without resetting the DLL.
At least 200 clocks after step 8, execute OCD Calibration ( Off Chip Driver impedance adjustment ).
If OCD calibration is not used, EMRS OCD Default command (A9=A8= A7=1) followed by EMRS OCD
- 22 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
1. Calibration Mode Exit command (A9=A8=A7=0) must be issued with other operating parameters of EMRS.
2. The gDDR2 SDRAM is now ready for normal operation.
*1) To guarantee ODT off, VREF must be valid and a low level must be applied to the ODT pin.
Initialization Sequence after Power Up
tCH tCL
CK
/CK
tIS
CKE
VIH(ac)
ODT
Command
PRE
ALL
NOP
400ns
EMRS
tRP
PRE
ALL
MRS
tMRD
tMRD
DLL
ENABLE
REF
tRP
MRS
REF
tRFC
tRFC
EMRS
tMRD
ANY
CMD
EMRS
Follow OCD
Flowchart
tOIT
min. 200 Cycle
DLL
RESET
OCD
Default
OCD
CAL. MODE
EXIT
Programming the Mode Register
For application flexibility, burst length, burst type, CAS latency, DLL reset function, write recovery time(tWR) 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(MR) or Extended Mode Registers(EMR(#)) can be altered by re-executing the MRS and EMRS Commands. If the user chooses to modify only a subset of the MRS or EMRS variables, all
variables must be redefined when the MRS or EMRS commands are issued.
MRS, EMRS and Reset DLL do not affect array contents, which means reinitialization including those can be executed
any time after power-up without affecting array contents.
- 23 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
gDDR2 SDRAM Mode Register Set (MRS)
The mode register stores the data for controlling the various operating modes of gDDR2 SDRAM. It controls CAS latency,
burst length, burst sequence, test mode, DLL reset, tWR and various vendor specific options to make gDDR2 SDRAM
useful for various applications. The default value of the mode register is not defined, therefore the mode register must be
written after power-up for proper operation. The mode register is written by asserting low on CS, RAS, CAS, WE, BA0 and
BA1, while controlling the state of address pins A0 ~ A15. The gDDR2 SDRAM should be in all bank precharge 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 gDDR SDRAM. Burst address sequence type is defined by A3,
CAS latency is defined by A4 ~ A6. The gDDR2 doesn’t support half clock latency mode. A7 is used for test mode. A8 is
used for DLL reset. A7 must be set to low for normal MRS operation. Write recovery time tWR is defined by A9 ~ A11.
Refer to the table for specific codes.
BA1
BA0
A12
RFU
0
PD
A11
A10
tWR
A9
A8
A7
DLL
TM
Active Power
Down exit time
A12
0
BA0
0
0
MRS
0
1
EMRS (1)
1
0
EMRS (2) : Reserved
1
1
EMRS (3) : Reserved
A4
A3
CAS Latency
A7
Slow exit (use tXARDS)
BA1
A5
BT
Normal
1
Test
A1
A0
Burst Length
A3
mode
0
A2
Burst Type
Test Mode
Fast exit (use tXARD)
1
A6
Type
0
Sequential
1
Interleave
MRS Mode
Burst Length
DLL
A8
DLL Reset
0
No
1
Yes
A10
A9
0
0
0
Reserved
0
0
1
Reserved
0
1
0
Reserved
0
1
1
4
1
0
0
5
1
0
1
6
1
1
0
7
1
1
1
8
A1
A0
Burst Length
0
1
0
4
0
1
1
8
CAS Latency
Write Recovery for Auto Precharge
A11
A2
MRS Select
A6
A5
A4
Latency
0
0
0
Reserved
0
0
1
Reserved
0
1
0
Reserved
0
1
1
Reserved
1
0
0
4
1
0
1
5
1
1
0
6
1
1
1
7
*1 : A13 is reserved for future use and must be programmed to 0 when setting the mode register.
BA2 and A14 are not used for 512Mb, but used for 1Gb and 2Gb gDDR2 SDRAMs. A15 is reserved for future
usage.
*2 : 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 a non-integer value to the next integer
(WR[cycles] = tWR(ns)/tCK(ns)). The mode register must be programmed to this value. This is also used with tRP to determine tDAL.
- 24 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
gDDR2 SDRAM Extended Mode Register Set
EMRS(1)
The extended mode register(1) stores the data for enabling or disabling the DLL, output driver strength, ODT value selection and additive latency. The default value of the extended mode register is not defined, therefore the extended mode register must be written after power-up for proper operation. The extended mode register is written by asserting low on CS,
RAS, CAS, WE and high on BA0, while controlling the states of address pins A0 ~ A12. The gDDR2 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. A0 is used for DLL enable or disable. A1 is used for enabling a half strength data-output driver.
A3~A5 determines the additive latency, A2 and A6 are used for ODT value selection, A7~A9 are used for OCD control,
A10 is used for DQS# disable.
DLL Enable/Disable
The DLL must be enabled for normal operation. DLL enable is required during power up 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.
- 25 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
EMRS (1) Programming
BA1
BA0
A12
A11
A10
0
1
Qoff
0
DQS
BA1
BA0
A9
A8
A7
OCD Program
MRS mode
A6
A5
Rtt
A4
Additive Latency
A6
A2
0
0
MRS
0
0
ODT Disabled
0
1
EMRS(1)
0
1
75 ohm
1
0
EMRS(2): Reserved
1
0
150 ohm
1
1
EMRS(3): Reserved
1
1
50 ohm
A1
A0
Rtt
D.I.C
DLL
Rtt (NOMINAL)
DLL Enable
0
Enable
1
Disable
A8
A7
A5
A4
A3
0
0
OCD Calibration mode exit; maintain setting
0
0
0
0
0
0
1
Drive(1)
0
0
1
1
0
1
0
Drive(0)
0
1
0
2
0
1
1
3
1
0
0
4
1
0
1
5
1
1
0
Reserved
1
1
1
Reserved
0
1
0
1
OCD Calibration Program
A0
A9
1
a
Adjust mode
OCD Calibration default
b
a: When Adjust mode is issued, AL from previously set value must be applied.
b: After setting to default, OCD mode needs to be exited by setting A9-A7 to
000. Refer to the following 3.2.2.3 section for detailed information
Additive Latency
Qoff (Optional)a
0
Output buffer enabled
1
Output buffer disabled
A1
a. Outputs disabled - DQs, DQSs, DQSs .
This feature is used in conjunction with dimm
IDD meaurements when IDDQ is not desired to
be included.
A10
A2
0
1
A12
A3
DQS
0
Enable
1
Disable
A10
(DQS Enable)
Output Driver
Impedance Control
Driver
Size
0
Normal
100%
1
Weak
60%
Strobe Function
Matrix
DQS
DQS
0 (Enable)
DQS
DQS
1 (Disable)
DQS
Hi-z
- 26 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
EMRS(2) Programming
BA1
BA0
1
0*1
BA1
A12
A11
A10
A9
A8
A7
A6
0*1
BA0
A5
A7
A3
MRS
1
Enable
0
1
EMRS(1)
0
Disable
1
0
EMRS(2)
1
1
EMRS(3): Reserved
A0
0
0
0
0
0
1
0
1
0
A0
Address Field
Extended Mode Register(2)
High Temperature Self-Refresh Rate Enable
0
A1
A1
PSAR*2
0
A2
A2
0*1
SRF
MRS mode
A4
Partial Array Self Refresh for 8 Banks
A2
A1
A0
Partial Array Self Refresh for 4 Banks
Full array
0
0
0
Full array
Half Array(BA[2:0]=000,001,010,&011)
0
0
1
Half Array(BA[1:0]=00&01)
Quarter Array(BA[2:0]=000&001)
0
1
0
Quarter Array(BA[1:0]=00)
0
1
1
1/8th array(BA[2:0]=000)
0
1
1
Not defined
1
0
0
3/4 array(BA[2:0]=010,011,100,101,110,&111)
1
0
0
3/4 array(BA[1:0]=01, 10&11)
1
0
1
Half array(BA[2:0]=100,101,110,&111)
1
0
1
Half array(BA[1:0]=10&11)
1
1
0
Quarter array(BA[2:0]=110&111)
1
1
0
Quarter array(BA[1:0]=11)
1
1
1
1/8th array(BA[2:0]=111)
1
1
1
Not defined
*1 : The rest bits in EMRS(2) is reserved for future use and all bits except A0, A1, A2, A7and BA0, BA1, must be programmed to 0 when setting the mode register during initialization.
.
*2 : If PASR (Partial Array Self Refresh) is enabled, data located in areas of the array beyond the specified location will
be loast if self refresh is entered. Data integrity will be maintained if tREF conditions are met and no Self Refresh command is issued. PASR is supported from the device of 90nm technology(512Mb C-die, 256Mb G-die, 1Gb A-die).
EMRS(3) Programming: Reserved*1
BA1
BA0
1
1
A12
A11
A10
A9
A8
A7
A6
A5
0*1
A4
A3
A2
A1
A0
Address Field
Extended Mode Register(3)
*1 : All bits in EMRS(3) except BA0 and BA1 are reserved for future use and must be programmed to 0 when setting the
mode register during initialization.
- 27 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Off-Chip Driver (OCD) Impedance Adjustment
gDDR2 SDRAM supports driver calibration feature and the flow chart below is an example of sequence. Every calibration
mode command should be followed by “OCD calibration mode exit” before any other command being issued. MRS should
be set before entering OCD impedance adjustment and ODT (On Die Termination) should be carefully controlled depending on system environment.
MRS shoud be set before entering OCD impedance adjustment and ODT should
be carefully controlled depending on system environment
Start
EMRS: OCD calibration mode exit
EMRS: Drive(1)
DQ & DQS High; DQS Low
EMRS: Drive(0)
DQ & DQS Low; DQS High
ALL OK
ALL OK
Test
Test
Need Calibration
Need Calibration
EMRS: OCD calibration mode exit
EMRS: OCD calibration mode exit
EMRS :
Enter Adjust Mode
EMRS :
Enter Adjust Mode
BL=4 code input to all DQs
Inc, Dec, or NOP
BL=4 code input to all DQs
Inc, Dec, or NOP
EMRS: OCD calibration mode exit
EMRS: OCD calibration mode exit
EMRS: OCD calibration mode exit
End
- 28 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Extended Mode Register Set for OCD impedance adjustment
OCD impedance adjustment can be done using the following EMRS mode. In drive mode all outputs are driven out by
gDDR2 SDRAM and drive of DQS is dependent on EMRS bit enabling DQS operation. In Drive(1) mode, all DQ, DQS signals are driven high and all DQS signals are driven low. In drive(0) mode, all DQ, DQS signals are driven low and all DQS
signals are driven high. In adjust mode, BL = 4 of operation code data must be used. In case of OCD calibration default,
output driver characteristics have a nominal impedance value of 18 ohms during nominal temperature and voltage conditions. Output driver characteristics for OCD calibration default are specified in section 6. OCD applies only to normal full
strength output drive setting defined by EMRS(1) and if half strength is set, OCD default output driver
characteristics are not applicable. When OCD calibration adjust mode is used, OCD default output driver
characteristics are not applicable. After OCD calibration is completed or driver strength is set to default,
subsequent EMRS commands not intended to adjust OCD characteristics must specify A9-A7 as '000' in order to maintain
the default or calibrated value.
Off- Chip-Driver program
A9
A8
A7
Operation
0
0
0
OCD calibration mode exit
0
0
1
Drive(1) DQ, DQShigh and DQS low
0
1
0
Drive(0) DQ, DQS low and DQS high
1
0
0
Adjust mode
1
1
1
OCD calibration default
OCD impedance adjust
To adjust output driver impedance, controllers must issue the ADJUST EMRS command along with a 4bit burst code to
gDDR2 SDRAM as in the folowing table. For this operation, Burst Length has to be set to BL = 4 via MRS command before
activating OCD and controllers must drive this burst code to all DQs at the same time. DT0 in the following table means all
DQ bits at bit time 0, DT1 at bit time 1, and so forth. The driver output impedance is adjusted for all gDDR2 SDRAM DQs
simultaneously and after OCD calibration, all DQs of a given gDDR2 SDRAM will be adjusted to the same driver strength
setting. The maximum step count for adjustment is 16 and when the limit is reached, further increment or decrement code
has no effect. The default setting may be any step within the 16 step range. When Adjust mode command is issued, AL
from previously set value must be applied
Off- Chip-Driver Program
4bit burst code inputs to all DQs
Operation
DT0
DT1
DT2
DT3
0
0
0
0
NOP (No operation)
Pull-up driver strength
0
0
0
1
Increase by 1 step
NOP
0
0
1
0
Decrease by 1 step
NOP
0
1
0
0
NOP
Increase by 1 step
1
0
0
0
NOP
Decrease by 1 step
0
1
0
1
Increase by 1 step
Increase by 1 step
0
1
1
0
Decrease by 1 step
Increase by 1 step
- 29 -
Pull-down driver strength
NOP (No operation)
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
1
0
0
1
Increase by 1 step
Decrease by 1 step
1
0
1
0
Decrease by 1 step
Decrease by 1 step
Other Combinations
Reserved
For proper operation of adjust mode, WL = RL - 1 = AL + CL - 1 clocks and tDS/tDH should be met as the following timing
diagram. For input data pattern for adjustment, DT0 - DT3 is a fixed order and "not affected by
MRS addressing mode (ie. sequential or interleave).
OCD adjust mode
CMD
EMRS
OCD calibration mode exit
NOP
NOP
NOP
NOP
NOP
EMRS
NOP
CK
CK
WL
WR
DQS
DQS_in
tDS tDH
DQ_in
VIH(AC)
VIH(DC)
VIL(AC)
VIL(DC)
DT0
DT1
DT2
DT3
DM
Drive Mode
Drive mode, both Drive(1) and Drive(0), is used for controllers to measure gDDR2 SDRAM Driver impedance. In this
mode, all outputs are driven out tOIT after “enter drive mode” command and all output drivers are turned-off tOIT after
“OCD calibration mode exit” command as the following timing diagram.
- 30 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
ODT (On Die Termination)
On Die Termination (ODT) is a feature that allows a DRAM to turn on/off termination resistance. For x16 configuration
ODT is applied to each DQ, UDQS/UDQS, LDQS/LDQS, UDM, and LDM signal via the ODT control pin. The ODT feature
is designed to improve signal integrity of the memory channel by allowing the DRAM controller to independently turn on/off
termination resistance for any or all DRAM devices.
The ODT function is supported for ACTIVE and STANDBY modes, and turned off and not supported in SELF REFRESH
mode.
Functional Representation of ODT
VDDQ
VDDQ
sw1
sw2
Rval2
Rval1
DRAM
Input
Buffer
Input
Pin
Rval1
Rval2
sw1
sw2
VSSQ
VSSQ
Switch sw1 or sw2 is enabled by ODT pin.
Selection between sw1 or sw2 is determined by “Rtt (nominal)” in EMRS
Termination included on all DQs, DM, DQS and DQS pins.
Target Rtt (ohm) = (Rval1) / 2 or (Rval2) / 2
ODT DC Electrical Characteristics
Parameter/Condition
Rtt effective impedance value for EMRS(A6,A2)=0,1; 75 ohm
Rtt effective impedance value for EMRS(A6,A2)=1,0; 150 ohm
Rtt mismatch tolerance between any pull-up/pull-down pair
Symbol
Rtt1(eff)
Rtt2(eff)
Rtt(mis)
Min
60
120
-3.75
Nom
75
150
Max
90
180
+3.75
Units
ohm
ohm
%
Notes
1
1
1
Note 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
VIH (AC) - VIL (AC)
Rtt(eff) =
I(VIH (AC)) - I(VIL (AC))
Measurement Definition for VM: Measure voltage (VM) at test pin (midpoint) with no load.
2 x Vm
delta VM =
VDDQ
-1
x 100%
- 31 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
ODT timing for active/standby mode
T0
T1
T2
T3
T4
T5
T6
CK
CK
CKE
tIS
tIS
VIH(AC)
ODT
VIL(AC)
tAOFD
tAOND
Internal
Term Res.
RTT
tAOF,min
tAON,max
tAON,min
tAOF,max
ODT timing for powerdown mode
T0
T1
T2
T3
T4
T5
T6
CK
CK
CKE
tIS
ODT
tIS
VIH(AC)
VIL(AC)
tAOFPD,max
tAOFPD,min
Internal
Term Res.
RTT
tAONPD,min
tAONPD,max
- 32 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
ODT timing mode switch at entering power down mode
T-5
T-4
T-3
T-2
CK
CK
T-1
T0
T2
T1
T3
T4
tANPD
tIS
CKE
Entering Slow Exit Active Power Down Mode
or Precharge Power Down Mode.
tIS
ODT
VIL(AC)
Active & Standby
mode timings to
be applied.
tAOFD
Internal
Term Res.
RTT
tIS
ODT
VIL(AC)
Power Down
mode timings to
be applied.
tAOFPDmax
Internal
Term Res.
RTT
tIS
ODT
VIH(AC)
tAOND
Internal
Term Res.
RTT
Active & Standby
mode timings to
be applied.
tIS
ODT
VIH(AC)
tAONPDmax
Internal
Term Res.
RTT
- 33 -
Power Down
mode timings to
be applied.
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
ODT timing mode switch at exiting power down mode
T0
T1
T4
T5
T6
T7
T8
T9
T10
T11
CK
CK
tIS
CKE
tAXPD
VIH(AC)
Exiting from Slow Active Power Down Mode
or Precharge Power Down Mode.
tIS
Active & Standby
mode timings to
be applied.
ODT
VIL(AC)
tAOFD
Internal
Term Res.
RTT
tIS
Power Down
mode timings to
be applied.
ODT
VIL(AC)
tAOFPDmax
Internal
Term Res.
RTT
tIS
Active & Standby
mode timings to
be applied.
VIH(AC)
ODT
tAOND
Internal
Term Res.
RTT
tIS
Power Down
mode timings to
be applied.
ODT
VIH(AC)
tAONPDmax
Internal
RTT
Term Res.
- 34 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Bank Activate Command
The Bank Activate command is issued by holding CAS and WE high with CS and RAS low at the rising edge of the clock.
The bank addresses BA0 and BA1 are used to select the desired bank. The row address A0 through A12 is used to determine which row to activate in the selected bank. The Bank Activate command must be applied before any Read or Write
operation can be executed. Immediately after the bank active command, the gDDR2 SDRAM can accept a read or write
command on the following clock cycle. If a R/W command is issued to a bank that has not satisfied the tRCDmin specification, then additive latency must be programmed into the device to delay when the R/W command is internally issued to the
device. The additive latency value must be chosen to assure tRCDmin is satisfied. Additive latencies of 0, 1, 2, 3, 4, 5 are
supported. Once a bank has been activated it must be precharged before another Bank Activate command can be applied
to the same bank. The bank active and precharge times are defined as tRAS and tRP, respectively. The minimum time
interval between successive Bank Activate commands to the same bank is determined by the RAS cycle time of the
device (tRC). The minimum time interval between Bank Activate commands is tRRD.
Bank Activate Command Cycle: tRCD = 3, AL = 2, tRP = 3, tRRD = 2, tCCD = 2
T0
T1
T2
T3
Tn
Tn+1
Tn+2
Tn+3
..........
CK / CK
Internal RAS-CAS delay (>= tRCDmin)
ADDRESS
Bank A
Row Addr.
Bank B
Bank B
Col. Addr.
Row Addr.
CAS-CAS delay time (tCCD)
additive latency delay (AL)
Bank A
Col. Addr.
RCD =1
A
. . . . . . . . Bank
..
Addr.
Bank B
Addr.
Bank A
Row Addr.
Bank B
Precharge
Bank A
Active
Read Begins
RAS - RAS delay time (>= tRRD)
COMMAND
: “H” or “L”
Bank A
Activate
Post CAS
Read A
Bank B
Activate
Post CAS
Read B
. . . . . . . .Bank
.. A
Precharge
Bank Active (>= tRAS)
Bank Precharge time (>= tRP)
RAS Cycle time (>= tRC)
- 35 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Read and Write Access Modes
After a bank has been activated, a read or write cycle can be executed. This is accomplished by setting RAS high, CS and
CAS low at the clock’s rising edge. WE must also be defined at this time to determine whether the access cycle is a read
operation (WE high) or a write operation (WE low).
The gDDR2 SDRAM provides a fast column access operation. A single Read or Write Command will initiate a serial read
or write operation on successive clock cycles. The boundary of the burst cycle is strictly restricted to specific segments of
the page length. For example, the 32Mbit x 4 I/O x 4 Bank chip has a page length of 2048 bits (defined by CA0-CA9,
CA11). The page length of 2048 is divided into 512 or 256 uniquely addressable boundary segments depending on burst
length, 512 for 4 bit burst, 256 for 8 bit burst respectively. A 4-bit or 8 bit burst operation will occur entirely within one of the
512 or 256 groups beginning with the column address supplied to the device during the Read or Write Command (CA0CA9, CA11). The second, third and fourth access will also occur within this group segment, however, the burst order is a
function of the starting address, and the burst sequence.
A new burst access must not interrupt the previous 4 bit burst operation in case of BL = 4 setting. However, in case of BL
= 8 setting, two cases of interrupt by a new burst access are allowed, one reads interrupted by a read, the other writes
interrupted by a write with 4 bit burst boundry respectively. The minimum CAS to CAS delay is defined by tCCD, and is a
minimum of 2 clocks for read or write cycles.
- 36 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Posted CAS
Posted CAS operation is supported to make command and data bus efficient for sustainable bandwidths in gDDR2
SDRAM. In this operation, the gDDR2 SDRAM allows a CAS read or write command to be issued immediately after the
RAS bank activate command (or any time during the RAS-CAS-delay time, tRCD, period). The command is held for the
time of the Additive Latency (AL) before it is issued inside the device. The Read Latency (RL) is controlled by the sum of
AL and the CAS latency (CL). Therefore if a user chooses to issue a R/W command before the tRCDmin, then AL (greater
than 0) must be written into the EMR(1). The Write Latency (WL) is always defined as RL - 1 (read latency -1) where read
latency is defined as the sum of additive latency plus CAS latency (RL=AL+CL). Read or Write operations using AL allow
seamless bursts (refer to seamless operation timing diagram examples in Read burst and Write burst section)
Examples of posted CAS operation
Example 1
Read followed by a write to the same bank
[AL = 2 and CL = 3, RL = (AL + CL) = 5, WL = (RL - 1) = 4]
-1
0
1
2
3
4
5
6
7
8
9
10
11
12
11
12
CK/CK
Active
A-Bank
CMD
Write
A-Bank
Read
A-Bank
DQS/DQS
> = tRCD
DQ
Example 2
WL = RL -1 = 4
CL = 3
AL = 2
RL = AL + CL = 5
Dout0
Dout1
Dout2
Dout3
Din0
Din1
Din2
Din3
> = tRAC
Read followed by a write to the same bank
[AL = 0 and CL = 3, RL = (AL + CL) = 3, WL = (RL - 1) = 2]
-1
0
1
2
3
4
5
6
7
8
9
10
CK/CK
AL = 0
CMD
DQS/DQS
DQ
Active
A-Bank
Write
A-Bank
Read
A-Bank
WL = RL -1 = 2
CL = 3
> = tRCD
RL = AL + CL = 3
Dout0
Dout1
Dout2
Dout3
Din0
Din1
Din2
Din3
> = tRAC
- 37 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
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.
gDDR2 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 the address bit 3 (A3) of the MRS, 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 gDDR2 SDRAM devices.
Burst Length and Sequence
BL = 4
Burst Length
Starting Address (A1 A0)
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
Starting Address (A2 A1 A0)
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
4
BL = 8
Burst Length
8
Note: Page length is a function of I/O organization and column addressin
- 38 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Burst Read Command
The Burst Read command is initiated by having CS and CAS low while holding RAS and WE high at the rising edge of the
clock. The address inputs determine the starting column address for the burst. The delay from the start of the command to
when the data from the first cell appears on the outputs is equal to the value of the read latency (RL). The data strobe output (DQS) is driven low 1 clock cycle before valid data (DQ) is driven onto the data bus. The first bit of the burst is synchronized with the rising edge of the data strobe (DQS). Each subsequent data-out appears on the DQ pin in phase with the
DQS signal in a source synchronous manner. The RL is equal to an additive latency (AL) plus CAS latency (CL). The CL is
defined by the Mode Register Set (MRS), similar to the existing SDR and DDR SDRAMs. The AL is defined by the
Extended Mode Register Set (1)(EMRS(1)).
gDDR2 SDRAM pin timings are specified for either single ended mode or differen-tial 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 gDDR2 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 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 ohm to 10 Kohm resistor to insure proper operation.
tCH
tCL
CK
CK
CK
DQS
DQS
DQS
tRPST
tRPRE
DQ
Q
Q
Q
tDQSQmax
Q
tDQSQmax
tQH
tQH
Burst Read Operation: RL = 5 (AL = 2, CL = 3, BL = 4)
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK/CK
CMD
Posted CAS
READ A
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
=< tDQSCK
DQS
AL = 2
CL =3
RL = 5
DQs
DOUT A0
- 39 -
DOUT A1
DOUT A2
DOUT A3
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Burst Read Operation: RL = 3 (AL = 0 and CL = 3, BL = 8)
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK/CK
CMD
CAS
READ A
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
=< tDQSCK
DQS
CL =3
RL = 3
DQs
DOUT A0
DOUT A1
DOUT A2
DOUT A3
DOUT A4
DOUT A5
DOUT A6
DOUT A7
Burst Read followed by Burst Write: RL = 5, WL = (RL-1) = 4, BL = 4
T0
T1
Tn-1
Tn
Tn+1
Tn+2
Tn+3
Tn+4
Tn+5
NOP
NOP
NOP
NOP
CK/CK
CMD
Post CAS
READ A
NOP
Post CAS
NOP
WRITE A
tRTW (Read to Write turn around time)
NOP
DQS
RL =5
WL = RL - 1 = 4
DQ’s
DOUT A0
DOUT A1
DOUT A2
DOUT A3
DIN A0
DIN A1
DIN A2
DIN A3
The minimum time from the burst read command to the burst write command is defined by a read-to-write-turn-aroundtime, which is 4 clocks in case of BL = 4 operation, 6 clocks in case of BL = 8 operation.
- 40 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Seamless Burst Read Operation: RL = 5, AL = 2, and CL = 3, BL=4
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK/CK
CMD
Post CAS
READ A0
NOP
Post CAS
READ A4
NOP
NOP
NOP
NOP
NOP
NOP
DQS
CL =3
AL = 2
RL = 5
DQs
DOUT A0
DOUT A1
DOUT A2
DOUT A3
DOUT A4
DOUT A5
DOUT A6
The seamless burst read operation is supported by enabling a read command at every other clock for BL = 4 operation,
and every 4 clock for BL = 8 operation. This operation is allowed regardless of same or different banks as long as the
banks are activated.
- 41 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Reads Intrrupted by a Read
Burst read can only be interrupted by another read with 4 bit burst boundary. Any other case of read interrupt is not
allowed.
Read Burst Interrupt Timing Example: (CL=3, AL=0, RL=3, BL=8)
CK/CK
CMD
Read A
NOP
Read B
NOP
NOP
NOP
NOP
NOP
NOP
NOP
DQS/DQS
DQs
A0
A1
A2
A3
B0
B1
B2
B3
B4
B5
B6
B7
Notes:
1. Read burst interrupt function is only allowed on burst of 8. Burst interrupt of 4 is prohibited.
2. Read burst of 8 can only be interrupted by another Read command. Read burst interruption by Write command or
Precharge command is prohibited.
3. Read burst interrupt must occur exactly two clocks after previous Read command. Any other Read burst interrupt
timings are prohibited.
4. Read burst interruption is allowed to any bank inside DRAM.
5. Read burst with Auto Precharge enabled is not allowed to interrupt.
6. Read burst interruption is allowed by another Read with Auto Precharge command.
7. All command timings are referenced to burst length set in the mode register. They are not referenced to actual burst.
For example, Minimum Read to Precharge timing is AL + BL/2 where BL is the burst length set in the mode register
and not the actual burst (which is shorter because of interrupt).
- 42 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Burst Write Operation
The Burst Write command is initiated by having CS, CAS and WE low while holding RAS high at the rising edge of the
clock. The address inputs determine the starting column address. Write latency (WL) is defined by a read latency (RL)
minus one and is equal to (AL + CL -1). A data strobe signal (DQS) should be driven low (preamble) one clock prior to the
WL. The first data bit of the burst cycle must be applied to the DQ pins at the first rising edge of the DQS following the
preamble. The tDQSS specification must be satisfied for write cycles. The subsequent burst bit data are issued on successive edges of the DQS until the burst length is completed, which is 4 or 8 bit burst. When the burst has finished, any additional data supplied to the DQ pins will be ignored. The DQ Signal is ignored after the burst write operation is complete.
The time from the completion of the burst write to bank precharge is the write recovery time (WR).
gDDR2 SDRAM pin timings are specified for either single ended mode or differen-tial 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 gDDR2 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 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 ohm to 10K ohm resistor to insure proper operation.
tDQSH
DQS
DQS/
DQS
tDQSL
DQS
tWPRE
tWPST
VIH(ac)
DQ
D
VIL(ac)
tDS
VIH(dc)
D
tDH
tDS
VIH(ac)
DM
DMin
D
D
VIL(dc)
DMin
DMin
tDH
VIH(dc)
DMin
VIL(dc)
VIL(ac)
Burst Write Operation: RL = 5, WL = 4, tWR = 3 (AL=2, CL=3), BL = 4
T0
T1
T2
T3
T4
T5
T6
T7
Tn
CK/CK
CMD
Posted CAS
WRITE A
NOP
NOP
NOP
NOP
NOP
NOP
NOP
Precharge
Completion of
the Burst Write
< = tDQSS
DQS
WL = RL - 1 = 4
DQs
> = WR
DIN A0
- 43 -
DIN A1
DIN A2
DIN A3
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Burst Write Operation: RL = 3, WL = 2, tWR = 2 (AL=0, CL=3), BL = 4
T0
T1
T2
T3
T4
T5
T6
T7
Tn
CK/CK
CMD
CAS
WRITE A
NOP
NOP
NOP
NOP
NOP
Precharge
NOP
Bank A
Activate
Completion of
the Burst Write
< = tDQSS
DQS
WL = RL - 1 = 2
DQs
> = tRP
> = WR
DIN A0
DIN A1
DIN A2
DIN A3
Burst Write followed by Burst Read: RL = 5 (AL=2, CL=3), WL = 4, tWTR = 2, BL = 4
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
CK/CK
Write to Read = CL - 1 + BL/2 + tWTR
CMD
NOP
NOP
NOP
Post CAS
READ A
NOP
NOP
NOP
NOP
NOP
DQS
CL = 3
AL = 2
WL = RL - 1 = 4
RL =5
> = tWTR
DQ
DOUT A0
DOUT A1
DOUT A2
DIN
DOUT A3
The minimum number of clock from the burst write command to the burst read command is [CL - 1 + BL/2 + tWTR]. This
tWTR is not a write recovery time (tWR) but the time required to transfer the 4bit write data from the input buffer into sense
amplifiers in the array. tWTR is defined in AC spec table of this data sheet.
- 44 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Seamless Burst Write Operation: RL = 5, WL = 4, BL=4
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK/CK
CMD
Post CAS
WRITE A0
NOP
Post CAS
WRITE A1
NOP
NOP
NOP
NOP
NOP
NOP
DQS
WL = RL - 1 = 4
DQ’s
DIN A0
DIN A1
DIN A2
DIN A3
DIN A0
DIN A1
DIN A2
DIN A3
The seamless burst write operation is supported by enabling a write command every other clock for BL = 4 operation,
every four clocks for BL = 8 operation. This operation is allowed regardless of same or different banks as long as the banks
are activated.
- 45 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Writes intrrupted by a write
Burst write can only be interrupted by another write with 4 bit burst boundary. Any other case of write interrupt is not
allowed.
Write Burst Interrupt Timing Example: (CL=3, AL=0, RL=3, WL=2, BL=8)
CK/CK
CMD
NOP
Write A
NOP
Write B
NOP
NOP
NOP
NOP
NOP
NOP
DQS/DQS
DQs
A0
A1
A2
A3
B0
B1
B2
B3
B4
B5
B6
B7
Notes:
1. Write burst interrupt function is only allowed on burst of 8. Burst interrupt of 4 is prohibited.
2. Write burst of 8 can only be interrupted by another Write command. Write burst interruption by Read command or
Precharge command is prohibited.
3. Write burst interrupt must occur exactly two clocks after previous Write command. Any other Write burst interrupt
timings are prohibited.
4. Write burst interruption is allowed to any bank inside DRAM.
5. Write burst with Auto Precharge enabled is not allowed to interrupt.
6. Write burst interruption is allowed by another Write with Auto Precharge command.
7. All command timings are referenced to burst length set in the mode register. They are not referenced to actual burst.
For example, minimum Write to Precharge timing is WL+BL/2+tWR where tWR starts with the rising clock after the
un-interrupted burst end and not from the end of actual burst end.
- 46 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Write data mask
One write data mask (DM) pin for each 8 data bits (DQ) will be supported on gDDR2 SDRAMs, Consistent with the implementation on gDDR SDRAMs. It has identical timings on write operations as the data bits, and though used in a uni-directional manner, is internally loaded identically to data bits to insure matched system timing. DM of x16 bit organization is
not used during read cycles.
Data Mask Timing
DQS/
DQS
DQ
DM
VIH(ac) VIH(dc)
VIH(ac) VIH(dc)
VIL(ac) VIL(dc)
VIL(ac) VIL(dc)
tDS tDH
tDS tDH
Data Mask Function, WL=3, AL=0, BL = 4 shown
Case 1 : min tDQSS
CK
CK
COMMAND
Write
tWR
tDQSS
DQS/DQS
DQ
DM
Case 2 : max tDQSS
tDQSS
DQS/DQS
DQ
DM
- 47 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Precharge Command
The Precharge Command is used to precharge or close a bank that has been activated. The Precharge Command is triggered when CS, RAS and WE are low and CAS is high at the rising edge of the clock. The Precharge Command can be
used to precharge each bank independently or all banks simultaneously. Three address bits A10, BA0 and BA1 for
256Mb are used to define which bank to precharge when the command is issued.
Bank Selection for Precharge by Address Bits
BA0
Precharged
Bank(s)
A10
BA1
LOW
LOW
LOW
Bank 0 only
LOW
LOW
HIGH
Bank 1 only
LOW
HIGH
LOW
Bank 2 only
LOW
HIGH
HIGH
Bank 3 only
HIGH
DON’T CARE
DON’T CARE
All Banks
Remarks
Burst Read Operation Followed by Precharge
Minimum Read to precharge command spacing to the same bank = AL + BL/2 clocks.
For the earliest possible precharge, the precharge command may be issued on the rising edge which is “Additive
latency(AL) + BL/2 clocks” after a Read command. A new bank active (command) may be issued to the same bank after
the RAS precharge time (tRP). A precharge command cannot be issued until tRAS is satisfied.
The minimum Read to Precharge spacing has also to satisfy a minimum analog time from the rising clock edge that initiates the last 4-bit prefetch of a Read to Precharge command. This time is called tRTP (Read to Precharge). For BL = 4
this is the time from the actual read (AL after the Read command) to Precharge command. For BL = 8 this is the time from
AL + 2 clocks after the Read to the Precharge command.
- 48 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Example 1: Burst Read Operation Followed by Precharge:
RL = 4, AL = 1, CL = 3, BL = 4, tRTP <= 2 clocks
T0
T1
T2
T3
T4
T5
T6
T7
T8
NOP
Bank A
Active
NOP
T6
T7
T8
NOP
NOP
NOP
CK/CK
CMD
Post CAS
READ A
NOP
NOP
Precharge
NOP
NOP
AL + BL/2 clks
DQS
> = tRP
CL = 3
AL = 1
RL =4
DQ’s
DOUT A0
> = tRAS
DOUT A1
DOUT A2
DOUT A3
CL =3
> = tRTP
Example 2: Burst Read Operation Followed by Precharge:
RL = 4, AL = 1, CL = 3, BL = 8, tRTP <= 2 clocks
T0
T1
T2
T3
T4
T5
CK/CK
CMD
Post CAS
READ A
NOP
NOP
NOP
NOP
Precharge A
AL + BL/2 clks
DQS
CL = 3
AL = 1
RL =4
DQ’s
DOUT A0
DOUT A1
DOUT A2
DOUT A3
DOUT A4
DOUT A5
DOUT A6
DOUT A8
> = tRTP
first 4-bit prefetch
second 4-bit prefetch
- 49 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Example 3: Burst Read Operation Followed by Precharge:
RL = 5, AL = 2, CL = 3, BL = 4, tRTP <= 2 clocks
T0
T1
T2
T3
T4
T5
T6
T7
T8
Bank A
Activate
NOP
CK/CK
CMD
Posted CAS
READ A
NOP
NOP
NOP
Precharge A
NOP
NOP
AL + BL/2 clks
DQS
> = tRP
AL = 2
CL =3
RL =5
DQ’s
DOUT A0
> = tRAS
DOUT A1
DOUT A2
DOUT A3
CL =3
> = tRTP
Example 4: Burst Read Operation Followed by Precharge:
RL = 6, AL = 2, CL = 4, BL = 4, tRTP <= 2 clocks
T0
T1
T2
T3
T4
T5
T6
T7
T8
Bank A
Activate
NOP
CK/CK
CMD
Post CAS
READ A
NOP
NOP
NOP
Precharge A
NOP
NOP
AL + BL/2 Clks
DQS
> = tRP
CL =4
AL = 2
RL = 6
DQ’s
DOUT A0
> = tRAS
DOUT A1
DOUT A2
DOUT A3
CL =4
> = tRTP
- 50 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Example 5: Burst Read Operation Followed by Precharge:
RL = 4, AL = 0, CL = 4, BL = 8, tRTP > 2 clocks
T0
T1
T2
T3
T4
T5
T6
T7
T8
NOP
Bank A
Activate
CK/CK
CMD
Post CAS
READ A
NOP
NOP
NOP
NOP
NOP
Precharge A
AL + 2 Clks + max{tRTP;2 tCK}*
DQS
AL = 0
> = tRP
CL =4
RL = 4
DQ’s
DOUT A0
DOUT A1
DOUT A2
DOUT A3
DOUT A4
DOUT A5
DOUT A6
DOUT A8
> = tRAS
> = tRTP
first 4-bit prefetch
second 4-bit prefetch
* : rounded to next integer
- 51 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Burst Write followed by Precharge
Minimum Write to Precharge Command spacing to the same bank = WL + BL/2 clks + tWR
For write cycles, a delay must be satisfied from the completion of the last burst write cycle until the Precharge Command
can be issued. This delay is known as a write recovery time (tWR) referenced from the completion of the burst write to the
precharge command. No Precharge command should be issued prior to the tWR delay.
Example 1: Burst Write followed by Precharge: WL = (RL-1) =3, BL=4
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK/CK
CMD
Posted CAS
WRITE A
NOP
NOP
NOP
NOP
NOP
NOP
NOP
Precharge A
Completion of the Burst Write
> = tWR
DQS
WL = 3
DQs
DIN A0
DIN A1
DIN A2
DIN A3
Example 2: Burst Write followed by Precharge: WL = (RL-1) = 4, BL=4
T0
T1
T2
T3
T4
T5
T6
T7
T9
CK/CK
CMD
Posted CAS
WRITE A
NOP
NOP
NOP
NOP
NOP
NOP
NOP
Precharge A
Completion of the Burst Write
> = tWR
DQS
WL = 4
DQs
DIN A0
- 52 -
DIN A1
DIN A2
DIN A3
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Auto-Precharge Operation
Before a new row in an active bank can be opened, the active bank must be precharged using either the Precharge Command or the auto-precharge function. When a Read or a Write Command is given to the gDDR2 SDRAM, the CAS timing
accepts one extra address, column address A10, to allow the active bank to automatically begin precharge at the earliest
possible moment during the burst read or write cycle. If A10 is low when the READ or WRITE Command is issued, then
normal Read or Write burst operation is executed and the bank remains active at the completion of the burst sequence. If
A10 is high when the Read or Write Command is issued, then the auto-precharge function is engaged. During auto-precharge, a Read Command will execute as normal with the exception that the active bank will begin to precharge on the rising edge which is CAS latency (CL) clock cycles before the end of the read burst.
Auto-precharge also be implemented during Write commands. The precharge operation engaged by the Auto precharge
command will not begin until the last data of the burst write sequence is properly stored in the memory array.
This feature allows the precharge operation to be partially or completely hidden during burst read cycles (dependent upon
CAS latency) thus improving system performance for random data access. The RAS lockout circuit internally delays the
Precharge operation until the array restore operation has been completed (tRAS satisfied) so that the auto precharge command may be issued with any read or write command.
Burst Read with Auto Precharge
If A10 is high when a Read Command is issued, the Read with Auto-Precharge function is engaged. The gDDR2 SDRAM
starts an auto Precharge operation on the rising edge which is (AL + BL/2) cycles later than the read with AP command if
tRAS(min) and tRTP are satisfied.
If tRAS(min) is not satisfied at the edge, the start point of auto-precharge operation will be delayed until tRAS(min) is satisfied.
If tRTP(min) is not satisfied at the edge, the start point of auto-precharge operation will be delayed until tRTP(min) is satisfied.
In case the internal precharge is pushed out by tRTP, tRP starts at the point where the internal precharge happens (not at
the next rising clock edge after this event). So for BL = 4 the minimum time from Read_AP to the next Activate command
becomes AL + (tRTP + tRP)* (see example 2) for BL = 8 the time from Read_AP to the next Activate is AL + 2 + (tRTP +
tRP)*, where “*” means: “rouded up to the next integer”. In any event internal precharge does not start earlier than two
clocks after the last 4-bit prefetch.
A new bank activate (command) may be issued to the same bank if the following two conditions are satisfied simultaneously.
(1) The RAS precharge time (tRP) has been satisfied from the clock at which the auto precharge begins.
(2) The RAS cycle time (tRC) from the previous bank activation has been satisfied.
- 53 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Example 1: Burst Read Operation with Auto Precharge:
RL = 4, AL = 1, CL = 3, BL = 8, tRTP <= 2 clocks
T0
T1
T2
T3
T4
T5
T6
T7
NOP
NOP
NOP
T8
CK/CK
Post CAS
CMD
READ A
NOP
NOP
NOP
NOP
Bank A
Activate
Autoprecharge
AL + BL/2 clks
> = tRP
DQS
CL = 3
AL = 1
RL =4
DQ’s
DOUT A0
DOUT A1
DOUT A2
DOUT A3
DOUT A4
DOUT A5
DOUT A6
DOUT A8
> = tRTP
second 4-bit prefetch
first 4-bit prefetch
tRTP
Precharge begins here
Example 2: Burst Read Operation with Auto Precharge:
RL = 4, AL = 1, CL = 3, BL = 4, tRTP > 2 clocks
T0
T1
T2
T3
T4
T5
T6
T7
T8
NOP
NOP
Bank A
Activate
NOP
CK/CK
CMD
Post CAS
READ A
NOP
NOP
NOP
NOP
Autoprecharge
> = AL + tRTP + tRP
DQS
CL = 3
AL = 1
RL =4
DQ’s
DOUT A0
DOUT A1
DOUT A2
DOUT A3
4-bit prefetch
tRTP
Precharge begins here
- 54 -
tRP
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Example 3: Burst Read with Auto Precharge Followed by an activation to the Same Bank
(tRC Limit):
RL = 5 (AL = 2, CL = 3, internal tRCD = 3, BL = 4, tRTP <= 2 clocks)
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK/CK
A10 = 1
CMD
Post CAS
READ A
NOP
NOP
NOP
> = tRas(min)
NOP
NOP
NOP
Bank A
Activate
NOP
Auto Precharge Begins
DQS
> = tRP
AL = 2
CL =3
RL = 5
DQ’s
DOUT A0
DOUT A1
DOUT A2
DOUT A3
CL =3
> = tRC
Example 4: Burst Read with Auto Precharge Followed by an Activation to the Same Bank
(tRP Limit):
RL = 5 (AL = 2, CL = 3, internal tRCD = 3, BL = 4, tRTP <= 2 clocks)
T0
T1
T2
T3
T4
T5
T6
T7
T8
CK/CK
A10 = 1
CMD
Post CAS
READ A
NOP
NOP
NOP
NOP
NOP
Bank A
Activate
NOP
NOP
Auto Precharge Begins
> = tRas(min)
DQS
> = tRP
AL = 2
CL =3
RL = 5
DQ’s
DOUT A0
DOUT A1
DOUT A2
DOUT A3
CL =3
> = tRC
- 55 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Burst Write with Auto-Precharge
If A10 is high when a Write Command is issued, the Write with Auto-Precharge function is engaged. The gDDR2 SDRAM
automatically begins precharge operation after the completion of the burst write plus write recovery time (tWR). The bank
undergoing auto-precharge from the completion of the write burst may be reactivated if the following two conditions are
satisfied.
(1) The data-in to bank activate delay time (WR + tRP) has been satisfied.
(2) The RAS cycle time (tRC) from the previous bank activation has been satisfied.
Burst Write with Auto-Precharge (tRC Limit): WL = 2, tWR =2, tRP=3, BL=4
T0
T1
T2
T3
T4
T5
T6
T7
Tm
CK/CK
A10 = 1
CMD Post CAS
WRA BankA
NOP
NOP
NOP
NOP
NOP
Completion of the Burst Write
NOP
Bank A
Active
NOP
Auto Precharge Begins
DQS/DQS
DQs
> = tRP
> = WR
WL =RL - 1 = 2
DIN A0
DIN A1
DIN A2
DIN A3
> = tRC
Burst Write with Auto-Precharge (tWR + tRP): WL = 4, tWR =2, tRP=3, BL=4
T0
T3
T4
T5
T6
T7
T8
T9
T12
CK/CK
A10 = 1
CMD
Post CAS
WRA Bank A
NOP
NOP
NOP
NOP
NOP
Completion of the Burst Write
NOP
NOP
Bank A
Active
Auto Precharge Begins
DQS/DQS
> = WR
WL =RL - 1 = 4
DQs
DIN A0
DIN A1
DIN A2
> = tRP
DIN A3
> = tRC
- 56 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Precharge & Auto Precharge Clarification
To Command
Minimum Delay beween”From Command” to “To Command”
Unit
Notes
Precharge ( to same Bank as Read w/AP)
AL + BL/2 + tRTP - 2 * tCK
clks
1, 2
Precharge All
AL + BL/2 + tRTP - 2 * tCK
clks
1, 2
Precharge ( to same Bank as Write w/AP)
WL + BL/2 + WR
clks
2
From Command
Read w/AP
Write w/AP
Precharge All
WL + BL/2 + WR
clks
2
Precharge ( to same Bank as Precharge)
1 * tCK
clks
2
Precharge All
1 * tCK
clks
2
Precharge
1 * tCK
clks
2
Precharge All
1 * tCK
clks
2
Precharge
Precharge All
Notes:
1. The value of tRTP is decided by the equation : max( RU<tRTP/tCK>, 2) where RU stands for round up. This is required
to cover the max tCK case, which is 8 ns.
2. For a given bank, the precharge period of tRP should be counted from the latest precharge command issued to that
bank. Similarly, the precharge period of tRPall should be counted from the latest precharge all command ossued to the
DRAM.
2.2.7 Refresh Command
When CS, RAS and CAS are held low and WE high at the rising edge of the clock, the chip enters the Refresh mode
(REF). All banks of the gDDR2 SDRAM must be precharged and idle for a minimum of the Precharge time (tRP) before the
Refresh command (REF) can be applied. An address counter, internal to the device, supplies the bank address during the
refresh cycle. No control of the external address bus is required once this cycle has started.
When the refresh cycle has completed, all banks of the gDDR2 SDRAM will be in the precharged (idle) state. A delay
between the Refresh command (REF) and the next Activate command or subsequent Refresh command must be greater
than or equal to the Refresh cycle time (tRFC).
To allow for improved efficiency in scheduling and switching between tasks, some flexibility in the absolute refresh interval
is provided. A maximum of eight Refresh commands can be posted to any given gDDR2 SDRAM, meaning that the maximum absolute interval between any Refresh command and the next Refresh command is 9 * tREFI.
T0
T1
T2
T3
Tm
Tn
Tn + 1
CK/CK
High
CKE
CMD
Precharge
NOP
> = tRFC
> = tRFC
> = tRP
NOP
REF
REF
- 57 -
NOP
ANY
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Self Refresh Operation
The gDDR2 SDRAM device has a built-in timer to accommodate Self Refresh operation. The Self Refresh Command is
defined by having CS, RAS, CAS and CKE held low with WE high at the rising edge of the clock. ODT must be turned off
before issuing Self Refresh command, by either driving ODT pin low or using EMRS command. Once the Command is registered, CKE must be held low to keep the device in Self Refresh mode. When the gDDR2 SDRAM has entered Self
Refresh mode all of the external signals except CKE, are “don’t care”. Since CKE is an SSTL 2 input, VREF must be maintained during Self Refresh operation. The DRAM initiates a minimum of one one Auto Refresh command internally within
tCKE period once it enters Self Refresh mode. The clock is internally disabled during Self Refresh Operation to save
power. The minimum time that the gDDR2 SDRAM must remain in Self Refresh mode is tCKE. The user may change the
external clock frequency or halt the external clock one clock after Self-Refresh entry is registered, however, the clock must
be restarted and stable before the device can exit Self Refresh operation. Once Self Refresh Exit command is registered, a
delay equal or longer than the tXSNR or tXSRD must be satisfied before a valid command can be issued to the device.
CKE must remain high for the entire Self Refresh exit period tXSRD for proper operation. Upon exit from Self Refresh, the
gDDR2 SDRAM can be put back into Self Refresh mode after tXSRD expires. NOP or deselect commands must be registered on each positive clock edge during the Self Refresh exit interval. ODT should also be turned off during tXSRD. Upon
exit from Self Refresh, the gDDR2 SDRAM requires a minimum of one extra auto refresh command before it is put back
into Self Refresh mode.
T0
T1
T2
T3
T4
T5
T6
Tm
Tn
tCK
tCH tCL
CK
CK
> = tXSNR
tRP*
> = tXSRD
CKE
VIH(AC)
VIL(AC)
tIS
tIS
tAOFD
ODT
VIL(AC)
tIS
tIS tIH
VIH(AC)
CMD
VIL(AC)
Self
Refresh
VIH(DC)
VIL(DC)
NOP
NOP
NOP
Valid
- Device must be in the “All banks idle” state prior to entering Self Refresh mode.
- ODT must be turned off tAOFD before entering Self Refresh mode, and can be turned on again
when tXSRD timing is satisfied.
- tXSRD is applied for a Read or a Read with autoprecharge command
- tXSNR is applied for any command except a Read or a Read with autoprecharge command.
- 58 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Power-Down
Power-down is synchronously entered when CKE is registered low (along with Nop or Deselect command). CKE is not
allowed to go low while mode register or extended mode register command time, or read or write operation is in progress.
CKE is allowed to go low while any of other operations such as row activation, precharge or autoprecharge, or auto-refresh
is in progress, but power-down IDD spec will not be applied until finishing those operations. Timing diagrams are shown in
the following pages with details for entry into power down.
The DLL should be in a locked state when power-down is entered. Otherwise DLL should be reset after exiting power-down
mode for proper read operation. DRAM design guarantees it’s DLL in a locked state with any CKE intensive operations as
long as DRAM controller complies with DRAM specifications. Following figures show two examples of CKE intensive applications. In both examples, DRAM maintains DLL in a locked state throughout the period.
<Example of CKE instensive environment 1>
CK
CK
CKE
tCKE
tCKE
DRAM maintains DLL in locked state with intensive CKE operation
<Example of CKE Iintensive enviroment 2>
CK
CK
CKE
tXP
tCKE
CMD
REF
REF
REF
tREFI = 7.8 us
tREFI = 7.8 us
The pattern shown above can repeat over a long period of time. With this pattern,
DRAM maintains DLL in a locked state with temperature and voltage drift.
- 59 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
If power-down occurs when all banks are idle, this mode is referred to as precharge power-down; if power-down occurs
when there is a row active in any bank, this mode is referred to as active power-down. Entering power-down deactivates
the input and output buffers, excluding CK, CK, ODT and CKE. Also the DLL is disabled upon entering precharge powerdown or slow exit active power-down, but the DLL is kept enabled during fast exit active power-down. In power-down
mode, CKE low and a stable clock signal must be maintained at the inputs of the gDDR2 SDRAM, and ODT should be in
a valid state but all other input signals are “Don’t Care”. CKE low must be maintained until tCKE has been satisfied.
Power-down duration is limited by 9 times tREFI of the device.
The power-down state is synchronously exited when CKE is registered high (along with a Nop or Deselect command).
CKE high must be maintained until tCKE has been satisfied. A valid, executable command can be applied with powerdown exit latency, tXP, tXARD, or tXARDS, after CKE goes high. Power-down exit latency is defined at AC spec table of
this data sheet.
Basic Power Down Entry and Exit timing diagram
CK/CK
tIS
CKE
Command
tIH
VIH(AC)
VIH(DC)
VALID
tIH
tIS tIH
VIL(DC)
VIL(AC)
NOP
tCKE
tIH
tIS
VIH(AC)
NOP
VIH(DC)
VALID
VALID
tIS tIH
VIH(AC)
VIH(DC)
VALID
tXP, tXARD,
tXARDS
tCKE
tCKE
Enter Power-Down mode
Exit Power-Down mode
- 60 -
Don’t Care
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Read to power down entry
T0
T1
T2
Tx
Tx+1
Tx+2
Tx+3
Tx+4
Tx+5
Tx+6
Tx+7
Tx+8
Tx+9
CK
CK
CMD
Read operation starts with a read command and
CKE should be kept high until the end of burst operation.
RD
BL=4
CKE
AL + CL
DQ
Q
Q
Q
Q
DQS
DQS
T0
CMD
T1
T2
Tx
Tx+1
Tx+2
Tx+3
Tx+4
Tx+5
Tx+6
Tx+7
Tx+8
Tx+9
RD
CKE should be kept high until the end of burst operation.
BL=8
CKE
AL + CL
DQ
Q
Q
Q
Q
Q
Q
Q
Q
DQS
DQS
Read with Autoprecharge to power down entry
T0
T1
T2
Tx
Tx+1
Tx+2
Tx+3
Tx+4
Tx+5
Tx+6
Tx+7
Tx+8
Tx+9
CK
CK
CMD
RDA
PRE
BL=4
AL + BL/2
with tRTP = 7.5ns
& tRAS min satisfied
CKE
CKE should be kept high
until the end of burst operation.
AL + CL
DQ
Q
Q
Q
Q
DQS
DQS
T0
T1
T2
Tx
Tx+1
Tx+2
Tx+3
Tx+4
Tx+5
Tx+6
Tx+7
Tx+8
Tx+9
Start internal precharge
CMD
RDA
BL=8
AL + BL/2
with tRTP = 7.5ns
& tRAS min satisfied
PRE
CKE should be kept high
until the end of burst operation.
CKE
AL + CL
DQ
Q
Q
Q
Q
Q
Q
Q
Q
DQS
DQS
- 61 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Write to power down entry
T0
T1
Tm
Tm+1
Tm+2
Tm+3
Tx
Tx+1
Tx+2
Ty
Ty+1
Ty+2
Ty+3
Tm+5
Tx
Tx+1
Tx+2
Tx+3
Tx+4
Tx+2
Tx+3
Tx+4
Tx+5
Tx+6
Tx
Tx+1
Tx+2
Tx+3
Tx+4
CK
CK
CMD
WR
BL=4
CKE
WL
DQ
D
D
D
D
tWTR
DQS
DQS
T0
CMD
T1
Tm
Tm+1
Tm+2
Tm+3
Tm+4
D
D
D
D
WR
BL=8
CKE
WL
DQ
D
D
D
D
tWTR
DQS
DQS
Write with Autoprecharge to power down entry
T0
T1
Tm
Tm+1
Tm+2
Tm+3
Tx
Tx+1
CK
CK
CMD
WRA
PRE
BL=4
CKE
WL
DQ
D
D
D
D
WR*1
DQS
DQS
T0
T1
Tm
Tm+1
Tm+2
Tm+3
Tm+4
Tm+5
CK
CK
CMD
WRA
PRE
BL=8
CKE
DQ
WL
D
D
D
D
D
D
D
D
WR*1
DQS
DQS
* 1: WR is programmed through MRS
- 62 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Refresh command to power down entry
T0
T1
T2
T3
T4
T5
T6
T7
T8
T9
T10
T11
CK
CK
CMD
REF
CKE can go to low one clock after an Auto-refresh command
CKE
Active command to power down entry
CMD
ACT
CKE can go to low one clock after an Active command
CKE
Precharge/Precharge all command to power down entry
CMD
PR or
PRA
CKE can go to low one clock after a Precharge or Precharge all command
CKE
MRS/EMRS command to power down entry
CMD
MRS or
EMRS
CKE
tMRD
- 63 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Asynchronous CKE Low Event
DRAM requires CKE to be maintained “HIGH” for all valid operations as defined in this data sheet. If CKE asynchronously
drops “LOW” during any valid operation DRAM is not guaranteed to preserve the contents of array. If this event occurs,
memory controller must satisfy DRAM timing specification tDelay before turning off the clocks. Stable clocks must exist at
the input of DRAM before CKE is raised “HIGH” again. DRAM must be fully re-initialized (steps 4 thru 13) as described in
initialization sequence. DRAM is ready for normal operation after the initialization sequence. See AC timing parametric
table for tDelay specification
Stable clocks
tCK
CK#
CK
CKE
tDelay
CKE asynchronously drops low
Clocks can be turned
off after this point
- 64 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Input Clock Frequency Change during Precharge Power Down
gDDR2 SDRAM input clock frequency can be changed under following condition:
gDDR2 SDRAM is in precharged power down mode. ODT must be turned off and CKE must be at logic LOW level. A minimum of 2 clocks must be waited after CKE goes LOW before clock frequency may change. SDRAM input clock frequency is allowed to change only within minimum and maximum operating frequency specified for the particular speed
grade. During input clock frequency change, ODT and CKE must be held at stable LOW levels. Once input clock frequency is changed, stable new clocks must be provided to DRAM before precharge power down may be exited and DLL
must be RESET via EMRS after precharge power down exit. Depending on new clock frequency an additional MRS command may need to be issued to appropriately set the WR, CL etc.. During DLL re-lock period, ODT must remain off. After
the DLL lock time, the DRAM is ready to operate with new clock frequency.
Clock Frequency Change in Precharge Power Down Mode
T0
T1
T2
NOP
NOP
T4
Tx
Tx+1
Ty
Ty+1
Ty+2
Ty+3
Ty+4
Tz
CK
CK
CMD
CKE
NOP
NOP
Frequency Change
Occurs here
DLL
RESET
NOP
Valid
200 Clocks
ODT
tRP
tXP
ODT is off during
DLL RESET
tAOFD
Minimum 2 clocks
required before
changing frequency
Stable new clock
before power down exit
- 65 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
No Operation Command
The No Operation Command should be used in cases when the gDDR2 SDRAM is in an idle or a wait state. The purpose
of the No Operation Command (NOP) is to prevent the gDDR2 SDRAM from registering any unwanted commands
between operations. A No Operation Command is registered when CS is low with RAS, CAS, and WE held high at the rising edge of the clock. A No Operation Command will not terminate a previous operation that is still executing, such as a
burst read or write cycle.
Deselect Command
The Deselect Command performs the same function as a No Operation Command. Deselect Command occurs when CS is
brought high at the rising edge of the clock, the RAS, CAS, and WE signals become don’t cares.
- 66 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Command Truth Table.
Command truth table.
CKE
CS
RAS
CAS
WE
BA0
BA1
H
L
L
L
L
BA
H
H
L
L
L
H
X
X
X
X
1
Self Refresh Entry
H
L
L
L
L
H
X
X
X
X
1
H
X
X
X
Self Refresh Exit
L
H
X
X
X
X
1,7
L
H
H
H
Function
Previous
Cycle
Current
Cycle
(Extended) Mode Register Set
H
Refresh (REF)
A11
A10
A9 - A0
OP Code
Notes
1,2
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
Column
L
Column
1,2,3,
Write with Auto Precharge
H
H
L
H
L
L
BA
Column
H
Column
1,2,3,
Read
H
H
L
H
L
H
BA
Column
L
Column
1,2,3
Read with Auto-Precharge
H
H
L
H
L
H
BA
Column
H
Column
1,2,3
No Operation
H
X
L
H
H
H
X
X
X
X
1
Device Deselect
H
X
H
X
X
X
X
X
X
X
1
H
X
X
X
Power Down Entry
H
L
X
X
X
X
1,4
L
H
H
H
H
X
X
X
X
X
X
X
1,4
L
H
H
H
Power Down Exit
L
H
Row Address
1,2
1. All gDDR2 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, 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"
4. The Power Down Mode does not perform any refresh operations. The duration of Power Down is therefore limited by the refresh
requirements outlined
5. The state of ODT does not affect the states described in this table. The ODT function is not available during Self Refresh.
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.
- 67 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Clock Enable (CKE) Truth Table for Synchronous Transitions
CKE
Current State 2
Previous Cycle
(N-1)
1
Command (N) 3
Current Cycle
(N)
1
Action (N) 3
Notes
RAS, CAS, WE, CS
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
L
H
DESELECT or NOP
Self Refresh Exit
4, 5,9
H
L
DESELECT or NOP
Active Power Down Entry
4,8,10,11,13
H
L
DESELECT or NOP
Precharge Power Down Entry
4, 8, 10,11,13
H
L
REFRESH
Self Refresh Entry
6, 9, 11,13
H
H
Power Down
Self Refresh
Bank(s) Active
All Banks Idle
Refer to the Command Truth Table
7
Notes:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
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.
Current state is the state of the DDR SDRAM immediately prior to clock edge N.
COMMAND (N) is the command registered at clock edge N, and ACTION (N) is a result of COMMAND (N).
All states and sequences not shown are illegal or reserved unless explicitly described elsewhere in this document.
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.
Self Refresh mode can only be entered from the All Banks Idle state.
Must be a legal command as defined in the Command Truth Table.
Valid commands for Power Down Entry and Exit are NOP and DESELECT only.
Valid commands for Self Refresh Exit are NOP and DESELECT only.
Power Down and Self Refresh can not be entered while Read or Write operations, (Extended) Mode Register Set operations or Precharge operations are in progress. See section "Power Down" and "Self Refresh Command" for a detailed list of restrictions.
Minimum CKE high time is three clocks.; minimum CKE low time is three clocks.
The state of ODT does not affect the states described in this table. The ODT function is not available during Self Refresh.
The Power Down does not perform any refresh operations. The duration of Power Down Mode is therefore limited by the refresh requirements outlined.
CKE must be maintained high while the SDRAM is in OCD calibration mode .
“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 EMRS(1) ).
VREF must be maintained during Self Refresh operation.
DM Truth Table
Name (Functional)
DM
DQs
Note
Write enable
-
Valid
1
Write inhibit
H
X
1
1. Used to mask write data, provided coincident with the corresponding data
- 68 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Input Signal Overshoot/Undershoot Specification
AC Overshoot/Undershoot Specification for Address and Control Pins A0-A15, BA0-BA2, CS, RAS, CAS, WE,
CKE, ODT
Specification
Parameter
- 37
- 30
Maximum peak amplitude allowed for overshoot area (See following figyre):
0.9V
0.9V
Maximum peak amplitude allowed for undershoot area (See following figure):
0.9V
0.9V
Maximum overshoot area above VDD (See following figure).
0.56 V-ns
0.45 V-ns
Maximum undershoot area below VSS (See following figure).
0.56 V-ns
0.45 V-ns
Maximum Amplitude
Overshoot Area
Volts
(V)
VDD
VSS
Undershoot Area
Maximum Amplitude
Time (ns)
AC Overshoot and Undershoot Definition for Address and Control Pins
AC Overshoot/Undershoot Specification for Clock, Data, Strobe, and Mask Pins DQ, DQS, DM, CK, CK
Specification
Parameter
- 37
-30
Maximum peak amplitude allowed for overshoot area (See following figure):
0.9V
0.9V
Maximum peak amplitude allowed for undershoot area (See following figure):
0.9V
0.9V
Maximum overshoot area above VDDQ (See following figure):
0.28 V-ns
0.23 V-ns
Maximum undershoot area below VSSQ (See following figure):
0.28 V-ns
0.23 V-ns
Maximum Amplitude
Overshoot Area
Volts
(V)
VDDQ
VSSQ
Undershoot Area
Maximum Amplitude
Time (ns)
AC Overshoot and Undershoot Definition for Clock, Data, Strobe, and Mask Pins
- 69 -
Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Table 1. Full Strength Default Pulldown Driver Characteristics
Pulldow n Current (mA)
Voltage (V) Minimum (23.4 Ohms)
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
8.5
12.1
14.7
16.4
17.8
18.6
19.0
19.3
19.7
19.9
20.0
20.1
20.2
20.3
20.4
20.6
Nominal Default
Low (18 ohms)
Nominal Default
High (18 ohms)
11.3
16.5
21.2
25.0
28.3
30.9
33.0
34.5
35.5
36.1
36.6
36.9
37.1
37.4
37.6
37.7
37.9
11.8
16.8
22.1
27.6
32.4
36.9
40.9
44.6
47.7
50.4
52.6
54.2
55.9
57.1
58.4
59.6
Maximum (12.6 Ohms)
60.9
15.9
23.8
31.8
39.7
47.7
55.0
62.3
69.4
75.3
80.5
84.6
87.7
90.8
92.9
94.9
97.0
99.1
101.1
Figure 1. gDDR2 Default Pulldown Characteristics for Full Strength Driver
120
Pulldown current (mA)
100
Maximum
80
Nominal
Default
High
60
Nominal
Default
Low
40
20
Minimum
0
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8
0.3 0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9
VOUT to VSSQ (V)
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Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
Table 2. Full Strength Default Pullup Driver Characteristics
Pullup Current (mA)
Voltage (V) Minimum (23.4 Ohms)
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
Nominal Default
Low (18 ohms)
Nominal Default
High (18 ohms)
-11.1
-16.0
-20.3
-24.0
-27.2
-29.8
-31.9
-33.4
-34.6
-35.5
-36.2
-36.8
-37.2
-37.7
-38.0
-38.4
-38.6
-11.8
-17.0
-22.2
-27.5
-32.4
-36.9
-40.8
-44.5
-47.7
-50.4
-52.5
-54.2
-55.9
-57.1
-58.4
-59.6
-60.8
-8.5
-12.1
-14.7
-16.4
-17.8
-18.6
-19.0
-19.3
-19.7
-19.9
-20.0
-20.1
-20.2
-20.3
-20.4
-20.6
Maximum (12.6 Ohms)
-15.9
-23.8
-31.8
-39.7
-47.7
-55.0
-62.3
-69.4
-75.3
-80.5
-84.6
-87.7
-90.8
-92.9
-94.9
-97.0
-99.1
-101.1
Figure 2. gDDR2 Default Pullup Characteristics for Full Strength Output Driver
0
Pullup current (mA)
-20
Minimum
-40
Nominal
Default
Low
-60
Nominal
Default
High
-80
-100
Maximum
-120
0.2
0.4
0.3
0.6
0.5
0.8
0.7
1.0
0.9
1.2
1.1
1.4
1.3
1.6
1.5
1.8
1.7
1.9
VDDQ to VOUT (V)
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Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
gDDR2 SDRAM Default Output Driver V–I Characteristics
gDDR2 SDRAM output driver characteristics are defined for full strength default operation as selected by the EMRS1 bits
A7-A9 = ‘111’. Figures 1 and 2 show the driver characteristics graphically, and tables 1 and 2 show the same data in tabular format suitable for input into simulation tools. The driver characteristics evaluation conditions are:
Nominal Default 25 oC (T case), VDDQ = 1.8 V, typical process
Minimum TBD oC (T case), VDDQ = 1.7 V, slow–slow process
Maximum 0 oC (T case), VDDQ = 1.9 V, fast–fast process
Default Output Driver Characteristic Curves Notes:
1) The full variation in driver current from minimum to maximum process, temperature, and voltage will
lie within the outer bounding lines of the V–I curve of figures 1 and 2.
2) It is recommended that the ”typical” IBIS V–I curve lie within the inner bounding lines of the V–I curves
of figures 1 and 2.
Table 3. Full Strength Calibrated Pulldown Driver Characteristics
Calibrated Pulldow n Current (mA)
Voltage (V)
0.2
0.3
0.4
Nominal Minimum Nominal Low (18.75
Nominal High (17.25 Nominal Maximum (15
Nominal (18 ohms)
ohms)
(21 ohms)
ohms)
ohms)
9.5
14.3
18.7
10.7
16.0
21.0
11.5
16.6
21.6
11.8
17.4
23.0
13.3
20.0
27.0
Table 4. Full Strength Calibrated Pullup Driver Characteristics
Calibrated Pullup Current (mA)
Voltage (V)
0.2
0.3
0.4
Nominal Minimum Nominal Low (18.75
Nominal High (17.25Nominal Maximum (15
Nominal (18 ohms)
(21 ohms)
ohms)
ohms)
ohms)
-9.5
-14.3
-18.7
-10.7
-16.0
-21.0
-11.4
-16.5
-21.2
-11.8
-17.4
-23.0
-13.3
-20.0
-27.0
gDDR2 SDRAM Calibrated Output Driver V–I Characteristics
gDDR2 SDRAM output driver characteristics are defined for full strength calibrated operation as selected by the procedure outlined in Off-Chip Driver (OCD) Impedance Adjustment. Tables 3 and 4 show the data in tabular format suitable for
input into simulation tools. The nominal points represent a device at exactly 18 ohms. The nominal low and nominal high
values represent the range that can be achieved with a maximum 1.5 ohm step size with no calibration error at the exact
nominal conditions only (i.e. perfect calibration procedure, 1.5 ohm maximum step size guaranteed by specification).
Real system calibration error needs to be added to these values. It must be understood that these V-I curves as represented here or in supplier IBIS models need to be adjusted to a wider range as a result of any system calibration error.
Since this is a system specific phenomena, it cannot be quantified here. The values in the calibrated tables represent just
the DRAM portion of uncertainty while looking at one DQ only. If the cali
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Rev 1.6 (Apr. 2005)
256M gDDR2 SDRAM
K4N56163QF-GC
bration procedure is used, it is possible to cause the device to operate outside the bounds of the default
device characteristics tables and figures. In such a situation, the timing parameters in the specification cannot be guaranteed. It is solely up to the system application to ensure that the device is calibrated between the minimum and maximum
default values at all times. If this can’t be guaranteed by the system calibration procedure, re-calibration policy, and uncertainty with DQ to DQ variation, then it is recommended that only the default values be used. The nominal maximum and
minimum values represent the change in impedance from nominal low and high as a result of voltage and temperature
change from the nominal condition to the maximum and minimum conditions. If calibrated at an extreme condition, the
amount of variation could be as much as from the nominal minimum to the nominal maximum or vice versa. The driver
characteristics evaluation conditions are:
Nominal 25 oC (T case), VDDQ = 1.8 V, typical process
Nominal Low and Nominal High 25 oC (T case), VDDQ = 1.8 V, any process
Nominal Minimum TBD oC (T case), VDDQ = 1.7 V, any process
Nominal Maximum 0 oC (T case), VDDQ = 1.9 V, any process
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Rev 1.6 (Apr. 2005)