IS43/46LR16800F 2M x 16Bits x 4Banks Mobile DDR SDRAM Description The IS43/46LR16800F is 134,217,728 bits CMOS Mobile Double Data Rate Synchronous DRAM organized as 4 banks of 2,097,152 words x 16 bits. This product uses a double-data-rate architecture to achieve high-speed operation. The Data Input/ Output signals are transmitted on a 16-bit bus. The double data rate architecture is essentially a 2N prefetch architecture with an interface designed to transfer two data words per clock cycle at the I/O pins. This product offers fully synchronous operations referenced to both rising and falling edges of the clock. The data paths are internally pipelined and 2n-bits prefetched to achieve very high bandwidth. All input and output voltage levels are compatible with LVCMOS. Features • JEDEC standard 1.8V power supply. • 64ms refresh period (4K cycle) • VDD = 1.8V, VDDQ = 1.8V • Auto & self refresh • Four internal banks for concurrent operation • Concurrent Auto Precharge • Maximum clock frequency up to 166MHZ • MRS cycle with address key programs - CAS latency 2, 3 (clock) • Maximum data rate up to 333Mbps/pin - Burst length (2, 4, 8, 16) • Power Saving support - PASR (Partial Array Self Refresh) - Burst type (sequential & interleave) • Fully differential clock inputs (CK, /CK) - Auto TCSR (Temperature Compensated Self Refresh) • All inputs except data & DM are sampled at the rising - Deep Power Down Mode - Programmable Driver Strength Control by Full Strength edge of the system clock • Data I/O transaction on both edges of data strobe or 1/2, 1/4, 1/8 of Full Strength • Bidirectional data strobe per byte of data (DQS) • LVCMOS compatible inputs/outputs • DM for write masking only • 60-Ball FBGA package • Edge aligned data & data strobe output • Center aligned data & data strobe input Copyright © 2010 Integrated Silicon Solution, Inc. All rights reserved. ISSI reserves the right to make changes to this specification and its products at any time without notice. ISSI assumes no liability arising out of the application or use of any information, products or services described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and before placing orders for products. Integrated Silicon Solution, Inc. does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless Integrated Silicon Solution, Inc. receives written assurance to its satisfaction, that: a.) the risk of injury or damage has been minimized; b.) the user assume all such risks; and c.) potential liability of Integrated Silicon Solution, Inc is adequately protected under the circumstances Rev. A | Apr. 2012 www.issi.com - [email protected] 1 IS43/46LR16800F Figure1: 60Ball FBGA Ball Assignment 1 2 3 4 5 6 7 8 9 A VSS DQ15 VSSQ VDDQ DQ0 VDD B VDDQ DQ13 DQ14 DQ1 DQ2 VSSQ C VSSQ DQ11 DQ12 DQ3 DQ4 VDDQ D VDDQ DQ9 DQ10 DQ5 DQ6 VSSQ E VSSQ UDQS DQ8 DQ7 LDQS VDDQ F VSS UDM NC NC LDM VDD G CKE CK /CK /WE /CAS /RAS H A9 A11 NC /CS BA0 BA1 J A6 A7 A8 A10 A0 A1 K VSS A4 A5 A2 A3 VDD [Top View] Rev. A | Apr. 2012 www.issi.com - [email protected] 2 IS43/46LR16800F Table2 : Pin Descriptions Symbol CK, /CK CKE /CS Type Input Input Input Function Descriptions System Clock The system clock input. CK and /CK are differential clock inputs. All address and control input signals are registered on the crossing of the rising edge of CK and falling edge of /CK. Input and output data is referenced to the crossing of CK and /CK. Clock Enable CKE is clock enable controls input. CKE HIGH activates, and CKE LOW deactivates internal clock signals, and device input buffers and output drivers. CKE is synchronous for all functions except for SELF REFRESH EXIT, which is achieved asynchronously. Chip Select /CS enables (registered Low) and disables (registered High) the command decoder. All commands are masked when /CS IS REGISTERED high. /CS provides for external bank selection on systems with multiple banks. /CS is considered part of the command code. BA0, BA1 Input Bank Address BA0 and BA1 define to which bank an ACTIVE, READ, WRITE, or PRECHARGE command is being applied. BA0 and BA1 also determine which mode register (standard mode register or extended mode register) is loaded during a LOAD MODE REGISTER command. A0~A11 Input Address Row Address Column Address Auto Precharge /RAS, /CAS, /WE Input Row Address Strobe, Column Address Strobe, Write Enable /RAS, /CAS and /WE define the operation. Refer function truth table for details. LDM, UDM Input Data Input Mask DM is an input mask signal for write data. Input data is masked when DM is sampled HIGH along with that input data during a WRITE access. DM is sampled on both edges of DQS. Although DM balls are input-only. DQ0~DQ15 In/Output Data Input/Output Data input/output pin. LDQS, UDQS In/Output Data Input/Output Strobe Output with read data, input with write data. DQS is edgealigned with read data, centered in write data. Data strobe is used to capture data. : RA0~RA11 : CA0~CA8 : A10 VDD Supply Power Supply Power supply VSS Supply Ground Ground VDDQ Supply DQ Power Supply Power supply for DQ VSSQ Supply DQ Ground Ground for DQ No Connection No connection. NC Rev. A | Apr. 2012 NC www.issi.com - [email protected] 3 IS43/46LR16800F Figure2 : Functional Block Diagram Self refresh Logic & timer Write Data Register 2-bit Prefetch Unit Internal Row Counter X16 Input Buffer & Logic PASR Extended Mode Register X32 2Mx16 BANK 3 Column Pre Decoder | | 32 | | Output Buffer & Logic LDM/UDM Memory Cell Array Sense AMP&I/O Gate Column Active 2Mx16 BANK 0 Row Decoders /WE 2Mx16 BANK 1 Row Decoders /CAS Refresh 2Mx16 BANK 2 Row Decoders /RAS Row Pre Decoder Row Decoders /CS Row Active State Machine /CK CK CKE DS | | 16 | | DQ0 . . . . . . . DQ15 Column Decoders Column Add Counter Bank Select UDQS,LDQS A0 BA0 Address Register Burst Counter Burst Length --------A11 Address Buffers A1 Mode Register DS CAS Latency Data Strobe Transmitter Data Strobe Receiver Data Out Control BA1 Rev. A | Apr. 2012 www.issi.com - [email protected] 4 IS43/46LR16800F Figure3 : Simplified State Diagram Power Applied DPDSX Power On Deep Power Down DPDS Self Refresh Precharge All Banks REFS REFSX MRS MRS EMRS Idle All Banks Precharged REFA CKEL CKEH ACT Active Power Down Precharge Power Down CKEH Row Active CKEL Burst Stop READ WRITE WRITE Auto Refresh READ A WRITE A READ WRITE READ BST READ WRITE A READ A PRE WRITE A PRE PRE PRE Precharge PREALL ACT = Active BST = Burst CKEL = Enter Power- Down CKEH = Exit Power-Down DPDS = Enter Deep Power-Down DPDSX = Exit Deep Power- Down EMRS = Ext. Mode Reg. Set MRS = Mode Register Set PRE = Precharge Rev. A | Apr. 2012 READ A Automatic sequence PREALL= Precharge All Banks REFA = Auto Refresh REFS = Enter Self Refresh REFSX = Exit Self Refresh READ = Read w/o Auto Precharge READ A = Read with Auto Precharge WRITE = Write w/o Auto Precharge WRITE A = Write with Auto Precharge www.issi.com - [email protected] 5 IS43/46LR16800F Figure4 : Mode Register Set (MRS) Definition BA1 A11 BA0 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 Address Bus 13 12 11 10 9 8 7 0 0 0 0 0 0 0 6 5 4 CAS Latency 3 BT M6 M5 M4 CAS Latency M3 Burst Type 0 0 0 Reserved 0 Sequential 0 0 1 Reserved 1 Interleave 0 1 0 0 1 1 1 0 1 2 1 0 Mode Register (Mx) Burst Length M2 M1 M0 0 0 2 0 3 0 0 Reserved 0 1 1 1 1 1 Burst Length M3 = 0 M3 = 1 0 Reserved Reserved 0 1 2 2 1 0 4 4 0 1 1 8 8 Reserved 1 0 0 16 16 0 Reserved 1 0 1 Reserved Reserved 1 Reserved 1 1 0 Reserved Reserved 1 1 1 Reserved Reserved Note: M13(BA1) and M12(BA0) must be set to “0” to select Mode Register (vs. the Extended Mode Register) Burst Type Accesses within a given burst may be programmed to be either sequential or interleaved; this is referred to as the burst type and is selected via bit M3. The ordering of accesses within a burst is determined by the burst length, the burst type and the starting column address, as shown in Table 3. Rev. A | Apr. 2012 www.issi.com - [email protected] 6 IS43/46LR16800F Table3 : Burst Definition Burst Length 2 4 8 16 Starting Column Address Order of Access within a Burst A3 A2 A1 A0 Sequential Mode Interleave Mode x x x 0 0-1 0-1 x x x 1 1-0 1-0 x x 0 0 0-1-2-3 0-1-2-3 x x 0 1 1-2-3-0 1-0-3-2 x x 1 0 2-3-0-1 2-3-0-1 x x 1 1 3-0-1-2 3-2-1-0 x 0 0 0 0-1-2-3-4-5-6-7 0-1-2-3-4-5-6-7 x 0 0 1 1-2-3-4-5-6-7-0 1-0-3-2-5-4-7-6 x 0 1 0 2-3-4-5-6-7-0-1 2-3-0-1-6-7-4-5 x 0 1 1 3-4-5-6-7-0-1-2 3-2-1-0-7-6-5-4 x 1 0 0 4-5-6-7-0-1-2-3 4-5-6-7-0-1-2-3 x 1 0 1 5-6-7-0-1-2-3-4 5-4-7-6-1-0-3-2 x 1 1 0 6-7-0-1-2-3-4-5 6-7-4-5-2-3-0-1 x 1 1 1 7-0-1-2-3-4-5-6 7-6-5-4-3-2-1-0 0 0 0 0 0-1-2-3-4-5-6-7-8-9-10-11-12-13-14-15 0-1-2-3-4-5-6-7-8-9-10-11-12-13-14-15 0 0 0 1 1-2-3-4-5-6-7-8-9-10-11-12-13-14-15-0 1-0-3-2-5-4-7-6-9-8-11-10-13-12-15-14 0 0 1 0 2-3-4-5-6-7-8-9-10-11-12-13-14-15-0-1 2-3-0-1-6-7-4-5-10-11-8-9-14-15-12-13 0 0 1 1 3-4-5-6-7-8-9-10-11-12-13-14-15-0-1-2 3-2-1-0-7-6-5-4-11-10-9-8-15-14-13-12 0 1 0 0 4-5-6-7-8-9-10-11-12-13-14-15-0-1-2-3 4-5-6-7-0-1-2-3-12-13-14-15-8-9-10-11 0 1 0 1 5-6-7-8-9-10-11-12-13-14-15-0-1-2-3-4 5-4-7-6-1-0-3-2-13-12-15-14-9-8-11-10 0 1 1 0 6-7-8-9-10-11-12-13-14-15-0-1-2-3-4-5 6-7-4-5-2-3-0-1-14-15-12-13-10-11-8-9 0 1 1 1 7-8-9-10-11-12-13-14-15-0-1-2-3-4-5-6 7-6-5-4-3-2-1-0-15-14-13-12-11-10-9-8 1 0 0 0 8-9-10-11-12-13-14-15-0-1-2-3-4-5-6-7 8-9-10-11-12-13-14-15-0-1-2-3-4-5-6-7 1 0 0 1 9-10-11-12-13-14-15-0-1-2-3-4-5-6-7-8 9-8-11-10-13-12-15-14-1-0-3-2-5-4-7-6 1 0 1 0 10-11-12-13-14-15-0-1-2-3-4-5-6-7-8-9 10-11-8-9-14-15-12-13-2-3-0-1-6-7-4-5 1 0 1 1 11-12-13-14-15-0-1-2-3-4-5-6-7-8-9-10 11-10-9-8-15-14-13-12-3-2-1-0-7-6-5-4 1 1 0 0 12-13-14-15-0-1-2-3-4-5-6-7-8-9-10-11 12-13-14-15-8-9-10-11-4-5-6-7-0-1-2-3 1 1 0 1 13-14-15-0-1-2-3-4-5-6-7-8-9-10-11-12 13-12-15-14-9-8-11-10-5-4-7-6-1-0-3-2 1 1 1 0 14-15-0-1-2-3-4-5-6-7-8-9-10-11-12-13 14-15-12-13-10-11-8-9-6-7-4-5-2-3-0-1 1 1 1 1 15-0-1-2-3-4-5-6-7-8-9-10-11-12-13-14 15-14-13-12-11-10-9-8-7-6-5-4-3-2-1-0 Note : 1. For a burst length of two, A1-A8 select the block of two burst; A0 selects the starting column within the block. 2. For a burst length of four, A2-A8 select the block of four burst; A0-A1 select the starting column within the block. 3. For a burst length of eight, A3-A8 select the block of eight burst; A0-A2 select the starting column within the block. 4. For a burst length of sixteen, A4-A8 select the block of eight burst; A0-A3 select the starting column within the block. 5. Whenever a boundary of the block is reached within a given sequence above, the following access wraps within the block. Rev. A | Apr. 2012 www.issi.com - [email protected] 7 IS43/46LR16800F Figure5 : Extended Mode Set (EMRS) Register BA1 BA0 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 Address Bus 13 12 11 10 9 8 7 1 0 0 0 0 0 0 6 5 DS 4 3 0 0 2 1 0 PASR Extended Mode Register (Ex) E6 E5 Driver Strength E2 E1 E0 Self Refresh Coverage 0 0 Full Strength 0 0 0 Four Banks 0 1 1/2 Strength 0 0 1 Two Bank (BA1=0) 1 0 1/4 Strength 0 1 0 One Bank (BA1=BA0=0) 1 1 1/8 Strength 0 1 1 Reserved 1 0 0 Reserved 1 0 1 One Eighth of Total Bank (BA1 = BA0 = Row Address MSB=0) 1 1 0 One Sixteenth of Total Bank (BA1 = BA0 = Row Address 2 MSBs=0) 1 1 1 Reserved Note: E13(BA1) must be set to “1” to select Extended Mode Register (vs. the base Mode Register) Rev. A | Apr. 2012 www.issi.com - [email protected] 8 IS43/46LR16800F Functional Description The 128Mb Mobile DDR SDRAM is a high-speed CMOS, dynamic random-access memory containing 134,271,728-bits. It is internally configured as a quad-bank DRAM. The 128Mb Mobile DDR SDRAM uses a double data rate architecture to achieve high speed operation. The double data rate architecture is essentially a 2n-prefetch architecture, with an interface designed to transfer two data words per clock cycle at the I/O balls, single read or write access for the 128Mb Mobile DDR SDRAM consists of a single 2n-bit wide, one-clock-cycle data transfer at the internal DRAM core and two corresponding n-bit wide, one-half-clock-cycle data transfers at the I/O balls. Read and Write accesses to the Mobile DDR SDRAM are burst oriented; accesses start at a selected location and continue for a programmed number of locations 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–A11 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. It should be noted that the DLL signal that is typically used on standard DDR devices is not necessary on the Mobile DDR SDRAM. It has been omitted to save power. Prior to normal operation, the Mobile DDR SDRAM must be powered up and initialized. The following sections provide detailed information covering device initialization, register definition, command descriptions and device operation. Power up and Initialization Mobile DDR SDRAM must be powered up and initialized in a predefined manner. Power must be applied to VDD and VDDQ (simultaneously). After power up, an initial pause of 200 usec is required. And a precharge all command will be issued to the Mobile DDR. Then, 2 or more Auto refresh cycles will be provided. After the Auto refresh cycles are completed, a Mode Register Set(MRS) command will be issued to program the specific mode of operation (Cas Latency, Burst length, etc.) And a Extended Mode Register Set(EMRS) command will be issued to Partial Array Self Refresh(PASR). The following these cycles, the Mobile DDR SDRAM is ready for normal operation. To ensure device functionality, there is a predefined sequence that must occur at device power up or if there is any interruption of device power. To properly initialize the Mobile DDR SDRAM, this sequence must be followed: 1. To prevent device latch-up, it is recommended the core power (VDD) and I/O power (VDDQ) be from the same power source and brought up simultaneously. If separate power sources are used, VDD must lead VDDQ. 2. Once power supply voltages are stable and the CKE has been driven HIGH, it is safe to apply the clock. 3. Once the clock is stable, a 200μs (minimum) delay is required by the Mobile DDR SDRAM prior to applying an executable command. During this time, NOP or DESELECT commands must be issued on the command bus. 4. Issue a PRECHARGE ALL command. 5. Issue NOP or DESELECT commands for at least tRP time. 6. Issue an AUTO REFRESH command followed by NOP or DESELECT commands for at least tRFC time. Issue a second AUTO REFRESH command followed by NOP or DESELECT commands for at least tRFC time. As part of the individualization sequence, two AUTO REFRESH commands must be issued. Typically, both of these commands are issued at this stage as described above. 7. Using the LOAD MODE REGISTER command, load the standard mode register as desired. 8. Issue NOP or DESELECT commands for at least tMRD time. 9. Using the LOAD MODE REGISTER command, load the extended mode register to the desired operating modes. Note that the order in which the standard and extended mode registers are programmed is not critical. 10. Issue NOP or DESELECT commands for at least tMRD time. 11. The Mobile DDR SDRAM has been properly initialized and is ready to receive any valid command. Rev. A | Apr. 2012 www.issi.com - [email protected] 9 IS43/46LR16800F Figure6 : Power up sequence VDD VDDQ T0 C LK /C LK T1 Ta0 Tb0 Tc0 PCG AREF AREF MRS Td0 Te0 Tf0 MRS ACT NOP3 CODE RA CODE RA BA0=L , BA1=H BA tCL LVCMOS HIGH LEVEL CKE tIS 1 Command NOP 2 tIH NOP tIS A0~A 9, A11 tIH CODE tIS All Banks A 10 tIS tIH CODE tIH tIS BA0, BA1 tIH BA0=L , BA1=L High- Z DQS, DQ DM T = 200 µs tCK tRP4 Power-up: VDD and CLK stable tRFC4 Don’ t care tRFC4 tMRD4 Load Standard Mode Register tMRD4 Load Extended Mode Register Notes: 1. PCG = PRECHARGE command, MRS = LOAD MODE REGISTER command, AREF = AUTOREFRESH command, ACT = ACTIVE command, RA = Row address, BA = Bank address. 2. NOP or DESELECT commands are required for at least 200μs. 3. Other valid commands are possible. 4. NOPs or DESELECTs are required during this time. Rev. A | Apr. 2012 www.issi.com - [email protected] 10 IS43/46LR16800F Mode Register The mode register is used to define the specific mode of operation of the Mobile DDR SDRAM. This definition includes the selection of a burst length, a burst type, a CAS latency. The mode register is programmed via the LOAD MODE REGISTER command and will retain the stored information until programmed again, the device goes into deep power-down mode, or the device loses power. Mode register bits A0-A2 specify the burst length, A3 specifies the type of burst (sequential or interleaved), A4-A6 specify the CAS latency, and A7-A11 should be set to zero. BA0 and BA1 must be zero to access the mode register. The mode register must be loaded when all banks are idle, and the controller must wait the specified time before initiating the subsequent operation. Violating either of these requirements will result in unspecified operation. Burst Length Read and write accesses to the Mobile DDR SDRAM are burst oriented, with the burst length being programmable, as shown in Figure (Mode Register Set Definition). The burst length determines the maximum number of column locations that can be accessed for a given READ or WRITE command. Burst lengths of 2, 4,8 or 16 are available for both the sequential and the interleaved burst types. Reserved states should not be used, as unknown operation or incompatibility with future versions may result. When a READ or WRITE command is issued, a block of columns equal to the burst length is effectively selected. All accesses for that burst take place within this block, meaning that the burst will wrap within the block if a boundary is reached. The block is uniquely selected by A1-A8 when the burst length is set to two; by A2-A8 when the burst length is set to four; by A3-A8 when the burst length is set to eight; and by A4-A8 when the burst length is set to sixteen. The remaining (least significant) address bit(s) is (are) used to select the starting location within the block. The programmed burst length applies to both READ and WRITE bursts. CAS Latency The CAS latency is the delay, in clock cycles, between the registration of a READ command and the availability of the first bit of output data. The latency can be set to 2, 3 clocks, as shown in Figure (Standard Mode Register Definition). For CL = 3, if the READ command is registered at clock edge n, then the data will be available at (n + 2 clocks + tAC). For CL = 2, if the READ command is registered at clock edge n, then the data will be available at (n + 1 clock + tAC). Figure7 : CAS Latency (BL=4) T0 T1 READ NOP T1 n T2 T2 n T3 T3 n T4 T4n /C L K C LK Command 1 tCK NOP NOP NOP tAC CL = 2 tRPRE tRPST DQS D OUT n DQ 2 tCK D OUT n+ 1 D OUT n+ 2 D OUT n+ 3 tAC CL = 3 tRPRE tRPST DQS D OUT n DQ DOUT n+1 D OUT n+ 2 DOUT n+ 3 Don ’ t care Rev. A | Apr. 2012 www.issi.com - [email protected] 11 IS43/46LR16800F Extended Mode Register The Extended Mode Register controls the functions beyond those controlled by the Mode Register. These additional functions are special features of the Mobile DDR SDRAM. They include Partial Array Self Refresh (PASR) and Driver Strength (DS). The Extended Mode Register is programmed via the Mode Register Set command (BA0=0, BA1=1) and retains the stored information until programmed again, the device goes into deep power-down mode, or the device loses power. The Extended Mode Register must be programmed with A7 through A11 set to “0”. The Extended Mode Register must be loaded when all banks are idle and no bursts are in progress, and the controller must wait the specified time before initiating any subsequent operation. Violating either of these requirements results in unspecified operation. Partial Array Self Refresh For further power savings during SELF REFRESH, the PASR feature allows the controller to select the amount of memory that will be refreshed during SELF REFRESH. The refresh options are as follows: • Full array: banks 0, 1, 2, and 3 • Half array: banks 0 and 1 • Quarter array: bank 0 • One eight array: half of bank 0 • One sixteen array: quarter of bank 0 WRITE and READ commands can still occur during standard operation, but only the selected banks will be refreshed during SELF REFRESH. Data in banks that are disabled will be lost. Output Driver Strength Because the Mobile DDR SDRAM is designed for use in smaller systems that are mostly point to point, an option to control the drive strength of the output buffers is available. Drive strength should be selected based on the expected loading of the memory bus. Bits A5 and A6 of the extended mode register can be used to select the driver strength of the DQ outputs. There are four allowable settings for the output drivers. Temperature Compensated Self Refresh In the Mobile DDR SDRAM, a temperature sensor is implemented for automatic control of the self refresh oscillator on the device. Temperature Compensated Self Refresh allows the controller to program the Refresh interval during SELF REFRESH mode, according to the case temperature of the Mobile SDRAM device. This allows great power savings during SELF REFRESH during most operating temperature ranges. Only during extreme temperatures would the controller have to select a TCSR level that will guarantee data during SELF REFRESH. Every cell in the DRAM requires refreshing due to the capacitor losing its charge over time. The refresh rate is dependent on temperature. At higher temperatures a capacitor loses charge quicker than at lower temperatures, requiring the cells to be refreshed more often. Historically, during Self Refresh, the refresh rate has been set to accommodate the worst case, or highest temperature range expected. Thus, during ambient temperatures, the power consumed during refresh was unnecessarily high, because the refresh rate was set to accommodate the higher temperatures. This temperature compensated refresh rate will save power when the DRAM is operating at normal temperatures. Rev. A | Apr. 2012 www.issi.com - [email protected] 12 IS43/46LR16800F Commands The following COMMANDS Truth Table and DM Operation Truth Table provide quick reference of available commands. This is followed by a written description of each command. Deselect The DESELECT function (/CS HIGH) prevents new commands from being executed by the Mobile DDR SDRAM. The Mobile DDR SDRAM is effectively deselected. Operations already in progress are not affected. NO Operation (NOP) The NO OPERATION (NOP) command is used to instruct the selected DDR SDRAM to perform a NOP (/CS = LOW, /RAS = /CAS = /WE = HIGH). This prevents unwanted commands from being registered during idle or wait states. Operations already in progress are not affected. Active The ACTIVE command is used to open (or activate) a row in a particular bank for a subsequent access. The value on the BA0, BA1 inputs selects the bank, and the address provided on inputs A0–A11 selects the row. This row remains active (or open) for accesses until a PRECHARGE command is issued to that bank. A PRECHARGE command must be issued before opening a different row in the same bank. Read The READ command is used to initiate a burst read access to an active row. The value on the BA0, BA1 inputs selects the bank, and the address provided on inputs A0–A8 selects the starting column location. The value on input A10 determines whether or not auto precharge is used. If auto precharge is selected, the row being accessed will be precharged at the end of the READ burst; if auto precharge is not selected, the row will remain open for subsequent accesses. Write The WRITE command is used to initiate a burst write access to an active row. The value on the BA0, BA1 inputs selects the bank, and the address provided on inputs A0-A8 selects the starting column location. The value on input A10 determines whether or not auto precharge is used. If auto precharge is selected, the row being accessed will be precharged at the end of the WRITE burst; if auto precharge is not selected, the row will remain open for subsequent accesses. Input data appearing on the DQs is written to the memory array subject to the DM input logic level appearing coincident with the data. If a given DM signal is registered LOW, the corresponding data will be written to memory; if the DM signal is registered HIGH, the corresponding data inputs will be ignored, and a WRITE will not be executed to that byte/column location. Precharge The PRECHARGE command is used to deactivate the open row in a particular bank or the open row in all banks. The bank(s) will be available for a subsequent row access a specified time (tRP) after the precharge command is issued. Except in the case of concurrent auto precharge, where a READ or WRITE command to a different bank is allowed as long as it does not interrupt the data transfer in the current bank and does not violate any other timing parameters. Input A10 determines whether one or all banks are to be precharged, and in the case where only one bank is to be precharged, inputs BA0, BA1select the bank. Otherwise BA0, BA1 are treated as “Don’t Care.” Once a bank has been precharged, it is in the idle state and must be activated prior to any READ or WRITE commands being issued to that bank. A PRECHARGE command will be treated as a NOP if there is no open row in that bank (idle state), or if the previously open row is already in the process of precharging. Rev. A | Apr. 2012 www.issi.com - [email protected] 13 IS43/46LR16800F Auto Precharge Auto precharge is a feature which performs the same individual-bank precharge function described above, but without requiring an explicit command. This is accomplished by using A10 to enable auto precharge in conjunction with a specific READ or WRITE command. A precharge of the bank/row that is addressed with the READ or WRITE command is automatically performed upon completion of the READ or WRITE burst. Auto precharge is nonpersistent in that it is either enabled or disabled for each individual READ or WRITE command. This device supports concurrent auto precharge if the command to the other bank does not interrupt the data transfer to the current bank. Auto precharge ensures that the precharge is initiated at the earliest valid stage within a burst. This “earliest valid stage” is determined as if an explicit PRECHARGE command was issued at the earliest possible time, without violating tRAS (MIN). The user must not issue another command to the same bank until the precharge time (tRP) is completed. Burst Terminate The BURST TERMINATE command is used to truncate READ bursts (with auto precharge disabled). The most recently registered READ command prior to the BURST TERMINATE command will be truncated. The open page which the READ burst was terminated from remains open. Auto Refresh AUTO REFRESH is used during normal operation of the Mobile DDR SDRAM and is analogous to /CAS-BEFORE-/RAS (CBR) REFRESH in FPM/EDO DRAMs. This command is nonpersistent, so it must be issued each time a refresh is required. The addressing is generated by the internal refresh controller. This makes the address bits a “Don’t Care” during an AUTO REFRESH command. The 128Mb Mobile DDR SDRAM requires AUTO REFRESH cycles at an average interval of tREFI (maximum). To allow for improved efficiency in scheduling and switching between tasks, some flexibility in the absolute refresh interval is provided. Although not a JEDEC requirement, to provide for future functionality features, CKE must be active (HIGH) during the auto refresh period. The auto refresh period begins when the AUTO REFRESH command is registered and ends tRFC later. Self Refresh The SELF REFRESH command can be used to retain data in the Mobile DDR SDRAM, even if the rest of the system is powered down. When in the self refresh mode, the Mobile DDR SDRAM retains data without external clocking. The SELF REFRESH command is initiated like an AUTO REFRESH command except CKE is disabled (LOW). All command and address input signals except CKE are “Don’t Care” during SELF REFRESH. During SELF REFRESH, the device is refreshed as identified in the external mode register (see PASR setting). For a the full array refresh, all four banks are refreshed simultaneously with the refresh frequency set by an internal self refresh oscillator. This oscillator changes due to the temperature sensors input. As the case temperature of the Mobile DDR SDRAM increases, the oscillation frequency will change to accommodate the change of temperature. This happens because the DRAM capacitors lose charge faster at higher temperatures. To ensure efficient power dissipation during self refresh, the oscillator will change to refresh at the slowest rate possible to maintain the devices data. The procedure for exiting SELF REFRESH requires a sequence of commands. First, Clock must be stable prior to CKE going back HIGH. Once CKE is HIGH, the Mobile DDR SDRAM must have NOP commands issued for tXSR is required for the completion of any internal refresh in progress. The self refresh command is not applicable for operation with tA > 85°C Deep Power-down Deep Power Down is an operating mode to achieve maximum power reduction by eliminating the power of the whole memory array of the devices. Data will not be retained once the device enters Deep Power Down Mode. This mode is entered by having all banks idle then /CS and /WE held low with /RAS and /CAS held high at the rising edge of the clock, while CKE is low. This mode is exited by asserting CKE high. Rev. A | Apr. 2012 www.issi.com - [email protected] 14 IS43/46LR16800F Table4: Command Truth Table Function /CS /RAS /CAS /WE BA A10/AP ADDR Note DESELECT (NOP) H X X X X X X 2 NO OPERATION (NOP) L H H H X X X 2 ACTIVE (Select Bank and activate Row) L L H H V Row Row READ (Select bank and column and start read burst) L H L H V L Col READ with AP (Read Burst with Auto recharge) L H L H V H Col WRITE (Select bank and column and start write burst) L H L L V L Col WRITE with AP (Write Burst with Auto recharge) L H L L V H Col 3 BURST TERMINATE or enter DEEP POWER DOWN L H H L X X X 4,5 PRECHARGE (Deactivate Row in selected bank) L L H L V L X 6 PRECHARGE ALL (Deactivate rows in all banks) L L H L X H X 6 AUTO REFRESH or enter SELF REFRESH L L L H X X X 7,8,9 MODE REGISTER SET L L L L V Op_Code 3 10 Table5 : DM Truth Table Function DM DQ Note Write Enable L Valid 11 Write Inhibit H X 11 Note: 1. All states and sequences not shown are illegal or reserved. 2. DESLECT and NOP are functionally interchangeable. 3. Autoprecharge is non-persistent. A10 High enables Autoprecharge, while A10 Low disables Autoprecharge 4. Burst Terminate applies to only Read bursts with autoprecharge disabled. This command is undefined and should not be used for Read with Autoprecharge enabled, and for Write bursts. 5. This command is BURST TERMINATE if CKE is High and DEEP POWER DOWN entry if CKE is Low. 6. If A10 is low, bank address determines which bank is to be precharged. If A10 is high, all banks are precharged and BA0-BA1 are don‘t care. 7. This command is AUTO REFRESH if CKE is High, and SELF REFRESH if CKE is low. 8. All address inputs and I/O are ''don't care'' except for CKE. Internal refresh counters control Bank and Row addressing. 9. All banks must be precharged before issuing an AUTO-REFRESH or SELF REFRESH command. 10. BA0 and BA1 value select between MRS and EMRS. 11. Used to mask write data, provided coincident with the corresponding data. 12. CKE is HIGH for all commands shown except SELF REFRESH and DEEP POWER-DOWN. Rev. A | Apr. 2012 www.issi.com - [email protected] 15 IS43/46LR16800F Table6 : CKE Truth Table CKEn-1 CKEn Current State COMMANDn ACTIONn L L Power Down X Maintain Power Down L L Self Refresh X Maintain Self Refresh L L Deep Power Down X Maintain Deep Power Down L H Power Down NOP or DESELECT Exit Power Down 5,6,9 L H Self Refresh NOP or DESELECT Exit Self Refresh 5,7,10 L H Deep Power Down NOP or DESELECT Exit Deep Power Down 5,8 H L All Banks Idle NOP or DESELECT Precharge Power Down entry 5 H L Bank(s) Active NOP or DESELECT Active Power Down Entry 5 H L All Banks Idle AUTO REFRESH Self Refresh Entry H L All Banks Idle BURST TERMINATE Enter Deep Power Down H H Note See the other Truth Tables Note: 1. CKEn is the logic state of CKE at clock edge n; CKEn-1 was the state of CKE at the previous clock edge. 2. Current state is the state of Mobile DDR immediately prior to clock edge n. 3. COMMANDn is the command registered at clock edge n, and ACTIONn is the result of COMMANDn. 4. All states and sequences not shown are illegal or reserved. 5. DESELECT and NOP are functionally interchangeable. 6. Power Down exit time (tXP) should elapse before a command other than NOP or DESELECT is issued. 7. SELF REFRESH exit time (tXSR) should elapse before a command other than NOP or DESELECT is issued. 8. The Deep Power-Down exit procedure must be followed as discussed in the Deep Power-Down section of the Functional Description. 9. The clock must toggle at least one time during the tXP period. 10. The clock must toggle at least once during the tXSR time. Rev. A | Apr. 2012 www.issi.com - [email protected] 16 IS43/46LR16800F Table7 : Current State BANKn Truth Table(COMMAND TO BANK n) Current State Any Idle Row Active Read (without Auto recharge) Write (without Auto precharge) Command Action Description Note /CS /RAS /CAS /WE H X X X DESELECT(NOP) Continue previous Operation L H H H NOP Continue previous Operation L L H H ACTIVE Select and activate row L L L H AUTO REFRESH Auto refresh 10 L L L L MODE REGISTER SET Mode register set 10 L L H H PRECHARGE No action if bank is idle L H L H READ Select Column & start read burst L H L L WRITE Select Column & start write burst L L H L PRECHARGE Deactivate Row in bank (or banks) L H L H READ Truncate Read & start new Read burst 5,6 L H L L WRITE Truncate Read & start new Write burst 5,6,13 L L H L PRECHARGE Truncate Read, start Precharge L H H L BURST TERMINATE Burst terminate L H L H READ Truncate Write & start new Read burst 5,6,12 L H L L WRITE Truncate Write & start new Write burst 5,6 L L H L PRECHARGE Truncate Write, start Precharge 12 4 11 Note: 1. The table applies when both CKEn-1 and CKEn are HIGH, and after tXSR or tXP has been met if the previous state was Self Refresh or Power Down. 2. DESELECT and NOP are functionally interchangeable. 3. All states and sequences not shown are illegal or reserved. 4. This command may or may not be bank specific. If all banks are being precharged, they must be in a valid state for precharging. 5. A command other than NOP should not be issued to the same bank while a READ or WRITE Burst with auto precharge is enabled. 6. The new Read or Write command could be auto precharge enabled or auto precharge disabled. 7. Current State Definitions: Idle: The bank has been precharged, and tRP has been met. Row Active: A row in the bank has been activated, and tRCD has been met. No data bursts/accesses and no register accesses are in progress. Read: A READ burst has been initiated, with AUTO PRECHARGE disabled, and has not yet terminated or been terminated. Write: a WRITE burst has been initiated, with AUTO PRECHARGE disabled, and has not yet terminated or been terminated. 8. The following states must not be interrupted by a command issued to the same bank. DESELECT or NOP commands or allowable commands to the other bank should be issued on any clock edge occurring during these states. Allowable commands to the other bank are determined by its current state and Truth Table3, and according to Truth Table 4. • Precharging: Starts with the registration of a PRECHARGE command and ends when tRP is met. Once tRP is met, the bank will be in the idle state. • Row Activating: Starts with registration of an ACTIVE command and ends when tRCD is met. Once tRCD is met, the bank will be in the ''row active'' state. • Read with AP Enabled: Starts with the registration of the READ command with AUTO PRECHARGE enabled and ends when tRP has been met. Once tRP has been met, the bank will be in the idle state. • Write with AP Enabled: Starts with registration of a WRITE command with AUTO PRECHARGE enabled and ends when tRP has been met. Once tRP is met, the bank will be in the idle state. Rev. A | Apr. 2012 www.issi.com - [email protected] 17 IS43/46LR16800F 9. The following states must not be interrupted by any executable command; DESELECT or NOP commands must be applied to each positive clock edge during these states. • Refreshing: Starts with registration of an AUTO REFRESH command and ends when tRFC is met. Once tRFC is met, the Mobile DDR will be in an ''all banks idle'' state. • Accessing Mode Register: Starts with registration of a MODE REGISTER SET command and ends when tMRD has been met. Once tMRD is met, the Mobile DDR will be in an ''all banks idle'' state. • Precharging All: Starts with the registration of a PRECHARGE ALL command and ends when tRP is met. Once tRP is met, the bank will be in the idle state. 10. Not bank-specific; requires that all banks are idle and no bursts are in progress. 11. Not bank-specific. BURST TERMINATE affects the most recent READ burst, regardless of bank. 12. Requires appropriate DM masking. 13. A WRITE command may be applied after the completion of the READ burst; otherwise, a Burst terminate must be used to end the READ prior to asserting a WRITE command. Rev. A | Apr. 2012 www.issi.com - [email protected] 18 IS43/46LR16800F Table8 : Current State BANKn Truth Table (COMMAND TO BANK m) Current State Any Idle Row Activating, Active, or Precharging Read with Auto Precha rge disabled Write with Auto precharge disabled Read with Auto Precharge Write with Auto precharge Rev. A | Apr. 2012 Command Action Description Note /CS /RAS /CAS /WE H X X X DESELECT(NOP) Continue previous Operation L H H H NOP Continue previous Operation X X X X ANY Any command allowed to bank m L L H H ACTIVE Activate Row L H L H READ Start READ burst 8 L H L L WRITE Start WRITE burst 8 L L H L PRECHARGE Precharge L L H H ACTIVE Activate Row L H L H READ State READ burst 8 L H L L WRITE Start WRITE burst 8,10 L L H L PRECHARGE Precharge L L H H ACTIVE Activate Row L H L H READ Start READ burst 8,9 L H L L WRITE Start WRITE burst 8 L L H L PRECHARGE Precharge L L H H ACTIVE Activate Row L H L H READ Start READ burst 5,8 L H L L WRITE Start WRITE burst 5,8,10 L L H L PRECHARGE Precharge L L H H ACTIVE Activate Row L H L H READ Start READ burst 5,8 L H L L WRITE Start WRITE burst 5,8 L L H L PRECHARGE Precharge www.issi.com - [email protected] 19 IS43/46LR16800F Note: 1. The table applies when both CKEn-1 and CKEn are HIGH, and after tXSR or tXP has been met if the previous state was Self Refresh or Power Down. 2. DESELECT and NOP are functionally interchangeable. 3. All states and sequences not shown are illegal or reserved. 4. Current State Definitions: Idle: The bank has been precharged, and tRP has been met. Row Active: A row in the bank has been activated, and tRCD has been met. No data bursts/accesses and no register accesses are in progress. Read: A READ burst has been initiated, with AUTO PRECHARGE disabled, and has not yet terminated or been terminated. Write: a WRITE burst has been initiated, with AUTO PRECHARGE disabled, and has not yet terminated or been terminated. 5. Read with AP enabled and Write with AP enabled: The read with Autoprecharge enabled or Write with Autoprecharge enabled states can be broken into two parts: the access period and the precharge period. For Read with AP, the precharge period is defined as if the same burst was executed with Auto Precharge disabled and then followed with the earliest possible PRECHARGE command that still accesses all the data in the burst. For Write with Auto precharge, the precharge period begins when tWR ends, with tWR measured as if Auto Precharge was disabled. The access period starts with registration of the command and ends where the precharge period (or tRP) begins. During the precharge period, of the Read with Autoprecharge enabled or Write with Autoprecharge enabled states, ACTIVE, PRECHARGE, READ, and WRITE commands to the other bank may be applied; during the access period, only ACTIVE and PRECHARGE commands to the other banks may be applied. In either case, all other related limitations apply (e.g. contention between READ data and WRITE data must be avoided). 6. AUTO REFRESH, SELF REFRESH, and MODE REGISTER SET commands may only be issued when all bank are idle. 7. A BURST TERMINATE command cannot be issued to another bank; It applies to the bank represented by the current state only. 8. READs or WRITEs listed in the Command column include READs and WRITEs with AUTO PRECHARGE enabled and READs and WRITEs with AUTO PRECHARGE disabled. 9. Requires appropriate DM masking. 10. A WRITE command may be applied after the completion of data output, otherwise a BURST TERMINATE command must be issued to end the READ prior to asserting a WRITE command. Rev. A | Apr. 2012 www.issi.com - [email protected] 20 IS43/46LR16800F Table9 : Absolute Maximum Rating Parameter Symbol Rating Ambient Temperature (Automotive, A2) Unit -40 ~ 105 Ambient Temperature (Automotive, A1) -40 ~ 85 TA Ambient Temperature (Industrial) °C -40 ~ 85 Ambient Temperature (Commercial) 0 ~ 70 TSTG -55 ~ 150 °C VIN, VOUT -0.3 ~ 2.7 V VDD, VDDQ -0.3 ~ 2.7 V Short Circuit Output Current IOS 50 mA Power Dissipation PD 0.7 W Storage Temperature Voltage on Any Pin relative to VSS Voltage on VDD relative to VSS Note : 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. Table10 : DC Operating Condition (Voltage referenced to VSS=0V, TA= 0 ~ 70 °C for Commercial; TA= -40 ~ 85 °C for Industrial or Automotive, A1; or TA= -40 ~ 105 °C for Automotive, A2) Parameter Symbol Min Typ Max Unit Note Power Supply Voltage VDD 1.7 1.8 1.95 V 1 Power Supply Voltage VDDQ 1.7 1.8 1.95 V 1,2 Input High Voltage VIH (DC) 0.7 x VDDQ VDDQ + 0.3 V Input Low Voltage VIL (DC) -0.3 0.3 x VDDQ V Output High Voltage VOH (DC) 0.9 x VDDQ - V IOH=-0.1mA Output Low Voltage VOL (DC) - 0.1 x VDDQ V IOL=0.1mA Input Leakage Current ILI -2 2 uA Output Leakage Current ILO -5 5 uA Note : 1. All Voltages are referenced to VSS = 0V 2. VDD and VDDQ must track each other, and VDDQ must not exceed the level of VDD Table11 : AC Operating Condition Parameter Symbol Min Max Unit Input High Voltage, all inputs VIH (AC) 0.8 x VDDQ VDDQ + 0.3 V Input Low Voltage, all inputs VIL (AC) -0.3 0.2 x VDDQ V VIX 0.4 x VDDQ 0.6 x VDDQ V Input Crossing Point Voltage, CK and /CK inputs Note 1 Note : 1. The value of VIX is expected to equal 0.5*VDDQ of the transmitting device and must track variations in the DC level of the same. Rev. A | Apr. 2012 www.issi.com - [email protected] 21 IS43/46LR16800F Table12 : Capacitance (TA=25 °C, f=1MHz, VDD=1.8V) Parameter Input Capacitance Pin Symbol Min Max Unit CK, /CK CI1 1.5 3.5 pF A0~A11, BA0~BA1, CKE, /CS, /RAS, /CAS, /WE CI2 1.5 3.0 pF LDM, UDM CI3 2 4.5 pF DQ0~DQ15, LDQS, UDQS CIO 2 4.5 pF Data & DQS Input/Output Capacitance Table13 : AC Operating Test Condition (TA= 0 ~ 70 °C for Commercial; TA= -40 ~ 85 °C for Industrial or Automotive, A1; or TA= -40 ~ 105 °C for Automotive, A2. VDD = 1.7V to 1.95V, VSS=0V) Parameter Symbol Value Unit VIH / VIL 0.8 x VDDQ / 0.2 x VDDQ V Input Timing Measurement Reference Level Voltage VTRIP 0.5 x VDDQ V Input Rise / Fall Time tR / tF 1/1 ns VOUTREF 0.5 x VDDQ V CL 20 pF AC Input High/Low Level Voltage Output Timing Measurement Reference Level Voltage Output Load Capacitance for Access Time Measurement Figure8 : Output load circuit VTT=0.5 x VDDQ VDDQ 13.9KΩ 50Ω Output Output Z0=50Ω 20pF 10.6KΩ 20pF DC Output Load Circuit AC Output Load Circuit Table14 : AC Overshoot/Undershoot Specification Parameter Specification Maximum Peak Amplitude allowed for Overshoot Area 0.9V Maximum Peak Amplitude allowed for Undershoot Area 0.9V Maximum Overshoot Area above VDD/VDDQ 3V-ns Maximum Undershoot Area below VSS/VSSQ 3V-ns Figure9 : AC Overshoot/Undershoot Definition Overshoot Area Maximum Amplitude Voltage [V] VDD/VDDQ VSS/VSSQ Maximum Amplitude Undershoot Area Time [ns] Rev. A | Apr. 2012 www.issi.com - [email protected] 22 IS43/46LR16800F Table15 : DC Characteristic (DC operating conditions unless otherwise noted) Parameter Symbol Test Condition Speed -6 -75 50 45 Unit Note mA 1 Operating one bank activeprecharge current IDD0 tRC = tRC(min), tCK = tCK(min), CKE is HIGH, /CS is HIGH between valid commands, address inputs are SWITCHING, data bus inputs are STABLE Precharge power-down standby current IDD2P All banks idle, CKE is LOW, /CS is HIGH, tCK = tCK(min), address and control inputs are SWITCHING, data bus inputs are STABLE 0.3 mA Precharge power-down standby current with clock stop IDD2PS All banks idle, CKE is LOW, /CS is HIGH, CK = LOW, /CK = HIGH, address and control inputs are SWITCHING, data bus inputs are STABLE 0.3 mA Precharge non power-down standby current IDD2N All banks idle, CKE is HIGH, /CS is HIGH, tCK = tCK(min) , address and control inputs are SWITCHING, data bus inputs are STABLE 10 mA Precharge non power-down standby current with clock stop IDD2NS All banks idle, CKE is HIGH, /CS is HIGH, CK = LOW, /CK = HIGH, address and control inputs are SWITCHING, data bus inputs are STABLE 4 mA Active power-down standby current IDD3P One bank active, CKE is LOW, /CS is HIGH, tCK = tCK(min), address and control inputs are SWITCHING, data bus inputs are STABLE 5 mA Active power-down standby current with clock stop IDD3PS One bank active, CKE is LOW, /CS is HIGH, CK = LOW, /CK = HIGH, address and control inputs are SWITCHING, data bus inputs are STABLE 1 mA Active non power-down standby current IDD3N One bank active, CKE is HIGH, /CS is HIGH, tCK = tCK(min), address and control inputs are SWITCHING, data bus inputs are STABLE 20 mA Active non power-down standby current with clock stop IDD3NS One bank active, CKE is HIGH, /CS is HIGH, CK = LOW, /CK = HIGH, address and control inputs are SWITCHING, data bus inputs are STABLE 10 mA Operating burst read current IDD4R One bank active, BL=4, CL=3, tCK = tCK(min), continuous read bursts, IOUT=0mA, address inputs are SWITCHING, 50% data change each burst transfer 85 80 mA 1 IDD4W One bank active, BL=4, tCK=tCK(min), continuous write bursts, address inputs are SWITCHING, 50% data change each burst transfer 45 40 mA 1 mA 2 Operating burst write current Auto Refresh Current PASR IDD5 2 Banks 1 Bank Half Bank Quarter Bank Standby Current in Deep Power Down Mode Note : 85°C 300 45°C 200 85°C 45°C 85°C IDD6 45°C 85°C CKE is LOW CK=LOW, /CK=HIGH tCK=tCK(min) Extended Mode Register set to all 0's, address and control inputs are STABLE, data bus inputs are STABLE 260 190 240 230 160 85°C 220 45°C 110 IDD8 Address and control inputs are STABLE, data bus inputs are STABLE uA 170 45°C 1. Measured with outputs open. 2. Refresh period is 64ms. Rev. A | Apr. 2012 90 TCSR 4 banks Self Refresh Current tRC=tRFC(min), tCK=tCK(min), burst refresh, CKE is HIGH, address and control inputs are SWITCHING, data bus inputs are STABLE 10 uA 3 3. Typical value at room temperature. www.issi.com - [email protected] 23 IS43/46LR16800F Table16: AC Characteristic (AC operation conditions unless otherwise noted) Parameter System Clock Cycle time DQ Output access time from CK, /CK Symbol CL=3 CL=2 CL=3 CL=2 tCK tAC -6 Min -75 Max Min 6 7.5 10 2.0 Max 10 5.5 2.0 6.0 Unit Note ns 1 ns 1 ns 2.0 8.0 2.0 8.0 Clock High pulse width tCH 0.45 0.55 0.45 0.55 tCK 0.45 0.55 0.45 0.55 tCK Clock Low pulse width tCL CKE min. pulse width (High/Low pulse width) tCKE 1 1 tCK DQ and DM Input Setup time tDS 0.6 0.9 ns 2, 3, 4 DQ and DM Input Hold time tDH 0.6 0.9 ns 2, 3, 4 DQ and DM Input Pulse width tDIPW 1.8 2.0 ns 5 Address and Control Input Setup time tIS 1.1 1.3 ns 4, 6, 7 Address and Control Input Hold time tIH 1.1 1.3 ns 4, 6, 7 Address and Control Input Pulse Width tIPW 2.7 3.0 ns 5 DQ & DQS Low-impedance time from CK, /CK tLZ 1.0 1.0 ns 8 DQ & DQS High-impedance time from CK, /CK tHZ ns 8 ns 9 DQS - DQ Skew tDQSQ Half Clock Period tHP Data Hold Skew Factor tQHS DQ / DQS Output Hold time from DQS tQH 5.5 6 0.5 tCH, tCL 0.6 tCH, tCL 0.65 tHP-tQHS ns 0.75 tHP-tQHS ns ns Write Command to first DQS Latching Transition tDQSS 0.75 1.25 0.75 1.25 tCK DQS Input High pulse Width tDQSH 0.35 0.6 0.4 0.6 tCK DQS Input Low pulse Width tDQSL 0.35 0.6 0.4 0.6 tCK DQS Falling Edge to CK Setup Time tDSS 0.2 tDSH 0.2 DQS Falling Edge Hold Time From CK Access Window of DQS from CK, /CK CL=3 CL=2 tDQSCK 0.2 tCK 0.2 tCK 2.0 5.5 2.0 6.0 2.0 8.0 2.0 8.0 ns ns ACTIVE to PRECHARGE Command Period tRAS 42 45 ACTIVE to ACTIVE Command Period tRC 60 75 ns Mode Register Set command cycle time tMRD 2 2 tCK Refresh Period tREF 64 64 ms 15 Average periodic refresh interval tREFI 15.6 15.6 us 10, 15 ns Auto Refresh Period tRFC 80 80 ns Active to Read or Write delay tRCD 18 22.5 ns Precharge command period tRP 18 22.5 ns Active Bank A to Active Bank B Delay tRRD 12 15 ns Write Recovery time tWR 15 15 ns Auto Precharge Write Recovery + Precharge time tDAL Internal Write to Read Command Delay tWTR DQS Read preamble CL=3 CL=2 tRPRE (tWR/tCK) + (tRP/tCK) 1 1 tCK 0.9 1.1 0.9 1.1 tCK 11 11 0.5 1.1 0.5 1.1 tCK DQS Read postamble tRPST 0.4 0.6 0.4 0.6 tCK DQS Write preamble tWPRE 0.25 0.25 tCK DQS Write preamble setup time tWPRES 0 0 ns 12 DQS Write postamble tWPST tCK 13 Exit Power Down to next valid command Delay tXP 14 Self Refresh Exit to next valid Command Delay tXSR Rev. A | Apr. 2012 0.4 0.6 0.4 0.6 1 1 tCK 120 120 ns www.issi.com - [email protected] 24 IS43/46LR16800F Note : 1. The clock frequency must remain constant (stable clock is defined as a signal cycling within timing constraints specified for the clock pin) during access or precharge states (READ, WRITE, including tDPL, and PRECHARGE commands). CKE may be used to reduce the data rate. 2. 4. The transition time for DQ, DM and DQS inputs is measured between VIL(DC) to VIH(AC) for rising input signals, and VIH(DC) to VIL(AC) for falling input signals. 3. DQS, DM and DQ input slew rate is specified to prevent double clocking of data and preserve setup and hold times. Signal transitions through the DC region must be monotonic. 4. Input slew rate ≥ 0.5V/ns and < 1.0V/ns. Input setup/hold slew rate [V/ns] ∆tDS/∆tIS [ps] ∆tDH/∆tIH [ps] 1.0 0 0 0.5 +150 +150 5. These parameters guarantee device timing but they are not necessarily tested on each device. 6. The transition time for address and command inputs is measured between VIH and VIL. 7. A CK,/CK slew rate must be ≥ 1.0V/ns (2.0V/ns if measured differentially) is assumed for this parameter. CK,/CK setup/hold slew rate [V/ns] ∆tDS/∆tIS [ps] ∆tDH/∆tIH [ps] 1.0 0 0 8. tHZ and tLZ transitions occur in the same access time windows as valid data transitions. These parameters are not referred to a specific voltage level, but specify when the device is no longer driving (HZ), or begins driving (LZ). 9. tDQSQ consists of data pin skew and output pattern effects, and p-channel to n-channel variation of the output drivers for any given cycle. 10. A maximum of eight Refresh commands can be posted to any given Low-Power DDR SDRAM, meaning that the maximum absolute interval between any Refresh command and the next Refresh command is 8*tREFI. 11. A low level on DQS may be maintained during High-Z states (DQS drivers disabled) by adding a weak pull-down element in the system. It is recommended to turn off the weak pull-down element during read and write bursts (DQS drivers enabled). 12. The specific requirement is that DQS be valid (HIGH, LOW, or some point on a valid transition) on or before this CK edge. A valid transition is defined as monotonic and meeting the input slew rate specifications of the device. When no writes were previously in progress on the bus, DQS will be transitioning from Hi-Z to logic LOW. If a previous write was in progress, DQS could be HIGH, LOW, or transitioning from HIGH to LOW at this time, depending on tDQSS. 13. The maximum limit for this parameter is not a device limit. The device operates with a greater value for this parameter, but system performance (bus turnaround) will degrade accordingly. 14. At least one clock pulse is required during txp. 15. The specifications in the table for tREF and tREFI are applicable for all temperature grades with TA ≤ 85°C. Only A2 temperature grade supports operation with TA ≥ 85°C, and these values must be further constrained with tREF max of 32ms, and tREFI max of 7.8µs. Rev. A | Apr. 2012 www.issi.com - [email protected] 25 IS43/46LR16800F Timing Diagram Bank/row Activation The Active command is used to activate a row in particular bank for a subsequent Read or Write access. The value of the BA0,BA1 inputs selects the bank, and the address provided on A0-A11(or the highest address bit) selects the row. Before any READ or WRITE commands can be issued to a bank within the Mobile DDR SDRAM, a row in that bank must be opened. This is accomplished via the ACTIVE command, which selects both the bank and the row to be activated. The row remains active until a PRECHARGE (or READ with AUTO PRECHARGE or WRITE with AUTO PRECHARGE) command is issued to the bank. A PRECHARGE (or READ with AUTO PRECHARGE or WRITE with AUTO PRECHARGE) command must be issued before opening a different row in the same bank. Figure10 : Active command CLK /CLK CKE /CS /RAS Notes : 1. RA : Row address /CAS 2. BA : Bank address /WE A0~A11 RA BA0, BA1 BA Don’t care Once a row is Open(with an ACTIVE command) a READ or WRITE command may be issued to that row, subject to the tRCD specification. tRCD(min) should be divided by the clock period and rounded up to the next whole number to determine the earliest clock edge after the ACTIVE command on which a READ or WRITE command can be entered. A subsequent ACTIVE command to a different row in the same bank can only be issued after the previous active row has been closed(precharge). The minimum time interval between successive ACTIVE commands to the same bank is defined by tRC. A subsequent ACTIVE command to another bank can be issued while the first bank is being accessed, which results in a reduction of total row-access overhead. The minimum time interval between successive ACTIVE commands to different banks is defined by tRRD. Figure11 : tRCD, tRRD, tRC T0 T1 T2 T3 T4 Ta0 Ta1 Ta2 RD /WT with AP NOP ACT NOP ACT /CLK CLK tIS tC K tIH tCH tCL Command ACT A0 -A11 ROW COL ROW ROW Bank a Bank a Bank b Bank a BA 0, BA 1 NOP NOP tRCD t RRD tRC Don’ t care Rev. A | Apr. 2012 www.issi.com - [email protected] 26 IS43/46LR16800F Read The READ command is used to initiate a Burst Read to an active row. The value of BA0 and BA1 selects the bank and address inputs select the starting column location. The value of A10 determines whether or not auto-precharge is used. If auto-precharge is selected, the row being accessed will be precharged at the end of the read burst; if auto precharge is not selected, the row will remain open for subsequent access. The valid dataout elements will be available CAS latency after the READ command is issued. The Mobile DDR drives the DQS during read operations. The initial low state of the DQS is known as the read preamble and the last dataout element is coincident with the read postamble. DQS is edge-aligned with read data. Upon completion of a burst, assuming no new READ commands have been initiated, the I/O's will go high-Z. Figure12 : Read command CLK /CLK CKE /CS /RAS /CAS Notes : 1. CA : Column address /WE 2. BA : Bank address A0~A8 CA 3. A10=High : Enable Auto precharge A10=Low : Disable Auto precharge A10 BA0, BA1 Don’ t care BA Figure13 : Read Data out timing (BL=4) T0 T1 READ NOP T1n T2 T2n T3 T3n T4 T4n /CLK CLK Command Address NOP NOP NOP Bank a COL n CL = 2 tRPST tAC tRPRE DQS DQ D OUT n DOUT n+1 D OUT n+ 2 D OUT n+ 3 CL =3 tAC tDQSCK tRPST tRPRE DQS tDQSQ D OUT n DQ tLZ Don’ t care D OUT n+ 1 tQH D OUT n+2 D OUT n+ 3 tHZ Notes: 1. BL=4 2. Shown with nominal tAC, tDQSCK and tDQSQ Rev. A | Apr. 2012 www.issi.com - [email protected] 27 IS43/46LR16800F Figure14 : Consecutive Read bursts (BL=4) T0 T1 T2 T3 T4 T5 Command READ NOP READ NOP NOP NOP Address Bank a COL n /CLK CLK Bank a COL m CL = 3 DQS DOUT n DQ D OUT n +1 DOUT n+2 D OUT n+ 3 D OUT m D OUT m +1 Don’ t care Notes: 1. Dout n or m = Data-Out from Column n or m 2. BL=4,8,16 (if 4, the bursts are concatenated; If 8 or 16, the second burst interrupts the first) 3. Shown with nominal tAC, tDQSCK and tDQSQ Figure15 : Non-Consecutive Read bursts (BL=4) T0 T1 T2 T3 T4 T5 Command READ NOP NOP READ NOP NOP A ddress Bank a COL n /CLK CLK NOP Bank a COL m CL=3 CL=3 DQS DOUT n DQ D OUT n+1 DOUT n+2 D OUT n+3 D OUT m DOUT m+1 Don ’ t care Notes: 1. Dout n or m = Data-Out from Column n or m 2. BL=4,8,16 (if 4, the bursts are concatenated; If 8 or 16, the second burst interrupts the first) 3. Shown with nominal tAC, tDQSCK and tDQSQ Rev. A | Apr. 2012 www.issi.com - [email protected] 28 IS43/46LR16800F Figure16 : Random Read access T0 T1 T2 T3 T4 T5 Command READ READ READ READ NOP NOP A ddress Bank a COL n Bank a COL m Bank a COL p Bank a COL q /CLK CLK NOP CL=3 DQS DOUT n DQ D OUT n+1 DOUT m D OUT m +1 D OUT p DOUT p+1 D OUT q D OUT q+1 Don ’ t care Notes: 1. Dout n or m,p,q = Data-Out from Column n or m,p,q 2. BL=2,4,8,16 (if 4,8 or 16, the following burst interrupts the previous) 3. Reads are to an Active row in any bank. 4. Shown with nominal tAC, tDQSCK and tDQSQ Truncated Reads Data from any READ burst may be truncated with a BURST TERMINATE command, as shown in Figure16. The BURST TERMINATE latency is equal to the READ (CAS) latency, i.e., the BURST TERMINATE command should be issued x cycles after the READ command, where x equals the number of desired data element pairs (pairs are required by the 2n-prefetch architecture). Data from any READ burst must be completed or truncated before a subsequent WRITE command can be issued. If truncation is necessary, the BURST TERMINATE command must be used. A READ burst may be followed by, or truncated with, a PRECHARGE command to the same bank provided that auto precharge was not activated. The PRECHARGE command should be issued x cycles after the READ command, where x equals the number of desired data element pairs (pairs are required by the n-prefetch architecture). This is shown in Figure (READ to PRECHARGE). Following the PRECHARGE command, a subsequent command to the same bank cannot be issued until tRP is met. Figure17 : Read Burst terminate (BL=4,8 or 16) T0 T1 T2 T3 T4 Command READ BST NOP NOP NOP Address Bank a COL n /CLK CLK CL= 3 DQS DQ DOUT n D OUT n+ 1 Don’ t care Notes: 1. Dout n = Data-Out from Column n 2. CKE=high 3. Shown with nominal tAC, tDQSCK and tDQSQ Rev. A | Apr. 2012 www.issi.com - [email protected] 29 IS43/46LR16800F Figure18 : Read to write terminate (BL=4,8 or 16) T0 T1 T2 T3 T4 T5 Command READ BST NOP NOP WRITE NOP Address Bank a /CLK CLK Bank a COL n COL m CL = 3 tDQSS ( NOM ) DQS DQ DOUT D OUT DIN D IN n n+ 1 m m +1 Don’ t care Notes: 1. Dout n = Data-Out from Column n , Din m = Data-In from Column m. 2. CKE=high 3. Shown with nominal tAC, tDQSCK and tDQSQ Figure19 : Read to Precharge (BL=4) T0 T1 READ NOP T2 T3 T4 T5 NOP NOP ACT /CLK CLK Command ADDRESS PCG Bank a COL n Bank a ( a, or all ) Bank a Row tRP CL = 3 DQS DQ D OUT n D OUT n+ 1 D OUT n+2 D OUT n+ 3 Don’ t care Notes: 1. Dout n = Data-Out from Column n. 2. Read to Precharge equals 2 tCK, which allows 2 data pairs of Data-Out. 3. Shown with nominal tAC, tDQSCK and tDQSQ Rev. A | Apr. 2012 www.issi.com - [email protected] 30 IS43/46LR16800F Write The WRITE command is used to initiate a Burst Write access to an active row. The value of BA0, BA1 selects the bank and address inputs select the starting column location. The value of A10 determines whether or not auto precharge is used.If autoprecharge is selected, the row being accessed will be precharged at the end of the write burst; if auto precharge is not selected, the row will remain open for subsequent access. Input data appearing on the data bus, is written to the memory array subject to the DM input logic level appearing coincident with the data. If a given DM signal is registered low, the corresponding data will be written to the memory; if the DM signal is registered high, the corresponding data-inputs will be ignored, and a write will not be executed to that byte/column location. The memory controller drives the DQS during write operations. The initial low state of the DQS is known as the write preamble and the low state following the last data-in element is write postamble. Upon completion of a burst, assuming no new commands have been initiated, the I/O's will stay high-Z and any additional input data will be ignored. Figure20 : Write command CLK /CLK CKE /CS /RAS Notes : 1. CA : Column address /CAS 2. BA : Bank address 3. A10=High : Enable Auto precharge /WE A10=Low : Disable Auto precharge A0~A8 CA A10 BA0, BA1 Don’ t care BA Figure21 : Write Burst (BL=4) T0 T1 Command WRITE NOP Address Bank a COL n T1n T2 T2n T3 /CLK CLK WRITE Bank a COL m tDQSS tDQSH tWPST DQS tWPRES tWPRE D IN n DQ tDS D IN n+ 1 tDH DIN n+ 2 D IN n+ 3 DM Don’ t care Notes: 1. Din n = Data-In from Column n. Rev. A | Apr. 2012 www.issi.com - [email protected] 31 IS43/46LR16800F Figure22 : Consecutive Write to write (BL=4) T0 T1 T2 T3 T4 T5 Command WRITE NOP WRITE NOP NOP NOP Address Bank a COL n /CLK CLK Bank a COL m tDQSS ( NOM ) DQS DIN n DQ D IN n+ 1 DIN n+ 2 D IN n+ 3 D IN m DIN m+ 1 D IN m +2 DIN m+ 3 DM Don ’ t care Notes: 1. Din n = Data-In from Column n. 2. Each Write command may be to any banks. Figure23 : Non-Consecutive Write to write (BL=4) T0 T1 T2 T3 T4 T5 Command WRITE NOP NOP WRITE NOP NOP Address Bank a COL n /CLK CLK NOP Bank a COL m tDQSS ( NOM ) tDQSS ( NOM ) DQS DQ D IN n D IN n+1 D IN n+ 2 D IN n+ 3 D IN m DIN m+ 1 D IN m +2 DIN m+ 3 DM Don’ t care Notes: 1. Din n = Data-In from Column n. 2. Each Write command may be to any banks. Rev. A | Apr. 2012 www.issi.com - [email protected] 32 IS43/46LR16800F Figure24 : Random Write to write T0 T1 T2 T3 T4 Command WRITE WRITE WRITE WRITE NOP Address Bank a COL n Bank a COL p Bank a COL m Bank a COL q /CLK CLK tDQSS (NOM) DQS D IN n DQ D IN n+1 D IN p D IN p+1 D IN m DIN m +1 D IN q D IN q+1 DM Don’ t care Notes: 1. Din n,p,m,q = Data-In from Column n,p,m,q. 2. Each Write command may be to any banks. Figure25 : Write to Read (Uninterrupting) T0 T1 T2 T3 T4 T5 T6 T7 Command WRITE NOP NOP NOP READ NOP NOP NOP Address Bank a COL n /CLK CLK Bank a COL m tDQSS (NOM) t WTR CL=3 DQS DQ D IN n D IN n+1 D IN n+2 D IN n+3 D OUT m DOUT m+1 D OUT m +2 DM Don’ t care Notes: 1. Din n = Data-In from Column n, Dout m = Data-Out from Column m. 2. tWTR is referenced from the first positive CK edge after the last data-in pair. 3. Read and Write command can be directed to different banks, in which case tWTR is not required and the Read command could be applied ealier. Rev. A | Apr. 2012 www.issi.com - [email protected] 33 IS43/46LR16800F Figure26 : Write to Read (Interrupting) T0 T1 T2 T3 T4 T5 T6 T7 Command WRITE NOP NOP READ NOP NOP NOP NOP A ddress Bank a COL n /CLK CLK Bank a COL m tDQSS (NOM) tWTR CL=3 DQS DIN n DQ D IN n+1 D OUT m DOUT m+1 D OUT m +2 DOUT m+3 DM Don ’ t care Notes: 1. Din n = Data-In from Column n, Dout m = Data-Out from Column m. 2. tWTR is referenced from the first positive CK edge after the last data-in pair. Figure27 : Write to Read (Odd number of data Interrupting) T0 T1 T2 T3 T4 T5 T6 T7 Command WRITE NOP NOP READ NOP NOP NOP NOP A ddress Bank a COL n / CLK CLK Bank a COL m tDQSS (NOM) tWTR CL=3 DQS DQ DIN n D OUT m DOUT m+1 D OUT m +2 DOUT m+3 DM Don’ t care Notes: 1. Din n = Data-In from Column n, Dout m = Data-Out from Column m. 2. tWTR is referenced from the first positive CK edge after the last data-in pair. Rev. A | Apr. 2012 www.issi.com - [email protected] 34 IS43/46LR16800F Figure28 : Write to Precharge (Uninterrupting) T0 T1 T2 T3 T4 T5 Command WRITE NOP NOP NOP NOP PCG A ddress Bank a COL n /CLK CLK tDQSS (NOM) tWR DQS D IN n DQ D IN n+1 D IN n+2 D IN n+3 DM Don’ t care Notes: 1. Din n = Data-In from Column n. 2. tWR is referenced from the first positive CK edge after the last data-in pair. 3. Read and Write command can be directed to different banks, in which case tWR is not required and the Read command could be applied ealier. Figure29 : Write to Precharge (Interrupting) T0 T1 T2 T3 T4 T5 Command WRITE NOP NOP NOP PCG NOP Address Bank a COL n /CLK CLK tDQSS (NOM) tWR DQS D IN n DQ D IN n+1 DM Don’ t care Notes: 1. Din n = Data-In from Column n. 2. tWR is referenced from the first positive CK edge after the last data-in pair. 3. Read and Write command can be directed to different banks, in which case tWR is not required and the Read command could be applied ealier. Rev. A | Apr. 2012 www.issi.com - [email protected] 35 IS43/46LR16800F Figure30 : Write to Precharge (Odd number of data Interrupting) T0 T1 T2 T3 T4 T5 Command WRITE NOP NOP NOP PCG NOP Address Bank a COL n /CLK CLK tDQSS (NOM) tWR DQS D IN n DQ DM Don’ t care Notes: 1. Din n = Data-In from Column n. 2. tWR is referenced from the first positive CK edge after the last data-in pair. 3. Read and Write command can be directed to different banks, in which case tWR is not required and the Read command could be applied ealier. Rev. A | Apr. 2012 www.issi.com - [email protected] 36 IS43/46LR16800F Precharge The Precharge command is used to deactivate the open row in a particular bank or the open row in all banks. The banks will be available for subsequent row access some specified time (tRP) after the Precharge command issued. Input A10 determines whether one or all banks are to be precharged. In the case where only one bank is to be precharged (A10=Low), inputs BA0,BA1 select the banks. When all banks are to be precharged (A10=High), inputs BA0,BA1 are treated as a “Don’t Care”. Once a bank has been precharged, it is in the idle state and must be actived prior to any Read or Write commands being issued to that bank. Figure31 : Precharge command CLK /CLK CKE /CS /RAS /CAS Notes : 1. BA : Bank address /WE A10 BA0, BA1 BA Don’t care Mode Register The mode register contains the specific mode of operation of the Mobile DDR SDRAM. This register includes the selection of a burst length ( 2, 4, 8, 16), a cas latency(2, 3), a burst type. The mode register set must be done before any activate command after the power up sequence. Any contents of the mode register be altered by re-programming the mode register through the execution of mode register set command. Figure32 : Mode Resister Set /CLK CLK CMD 0 1 3 4 Mode Resister Set Precharge All Bank tCK Rev. A | Apr. 2012 2 tRP 5 6 7 8 9 10 Command (any) 2 CK min www.issi.com - [email protected] 37 IS43/46LR16800F Auto refresh The Auto refresh command is used during normal operation of the Mobile DDR. It is non persistent, so must be issued each time a refresh is required. The refresh addressing is generated by the internal refresh controller. The Mobile DDR requires AUTO REFRESH commands at an average periodic interval of tREFI. To allow for improved efficiency in scheduling and switching between tasks, some flexibility in the absolute refresh interval is provided. A maximum of eight AUTO REFRESH commands can be posted to any given Mobile DDR, and the maximum absolute interval between any AUTO REFRESH command and the next AUTO REFRESH command is 8*tREFI. Figure33 : Auto refresh T0 T1 T2 T3 T4 Ta 0 Ta 2 Tb 0 Tb 0 /C L K CLK tIS tIH tIS tIH tC K CKE tCH tCL VALID NOP C ommand PCG VALID NOP NOP AREF NOP AREF NOP NOP A 0~ A 9, A 11 ACT RA All Banks A 10 RA One Bank BA BA 0, BA 1 BA DQS , DQ , DM tRP Don’ t care tRFC tRFC Self refresh This state retains data in the Mobile DDR, even if the rest of the system is powered down (even without external clocking). Note refresh interval timing while in Self Refresh mode is scheduled internally in the Mobile DDR and may vary and may not meet tREFI time. "Don't Care" except CKE, which must remain low. An internal refresh cycle is scheduled on Self Refresh entry. The procedure for exiting Self Refresh mode requires a series of commands. First clock must be stable before CKE going high. NOP commands should be issued for the duration of the refresh exit time (tXSR), because time is required for the completion of any internal refresh in progress. The use of SELF REFRESH mode introduces the possibility that an internally timed event can be missed when CKE is raised for exit from self refresh mode. Figure34 : Self refresh T1 T0 Ta 0 T a1 Tb0 /C LK C LK tIS tIH tIS tIH tIS tIS CKE C ommand NOP AREF NOP VALID VALID Address DQS , DQ, DM tRP Self-refresh mode entry Rev. A | Apr. 2012 tXSR Don’ t care Self-refresh mode exit www.issi.com - [email protected] 38 IS43/46LR16800F Power down Power down occurs if CKE is set low coincident with Device Deselect or NOP command and when no accesses are in progress. If power down occurs when all banks are idle, it is Precharge Power Down. If Power down occurs when one or more banks are Active, it is referred to as Active power down. The device cannot stay in this mode for longer than the refresh requirements of the device, without losing data. The power down state is exited by setting CKE high while issuing a Device Deselect or NOP command. A valid command can be issued after tXP. Figure35 : Power down (Active or Precharge) T0 T1 T2 Ta0 Ta1 Tb0 /CLK CLK tC K tIS tCH tCL t XP tIH tIS CKE tIS Command VALID tIS Address tIH NOP NOP VALID tIH VALID VALID DQS, DQ, DM Must not exceed refresh device limits Power-down mode entry Don’ t care Power-down mode exit Deep Power down The Deep Power-Down (DPD) mode enables very low standby currents. All internal voltage generators inside the Mobile DDR are stopped and all memory data is lost in this mode. All the information in the Mode Register and the Extended Mode Register is lost. Next Figure, DEEP POWER-DOWN COMMAND shows the DEEP POWER-DOWN command All banks must be in idle state with no activity on the data bus prior to entering the DPD mode. While in this state, CKE must be held in a constant low state. To exit the DPD mode, CKE is taken high after the clock is stable and NOP command must be maintained for at least 200 us. Figure36 : Deep Power down T0 T1 T2 Ta 0 Ta 1 Ta 2 Tb 0 /C LK C LK tIS T=200us tC KE CKE C ommand NOP DPD NOP Address NOP VALID VALID DQS, DQ , DM Deep Power -down mode entry Rev. A | Apr. 2012 Deep Power -down mode exit www.issi.com - [email protected] Don ’ t care 39 IS43/46LR16800F Clock Stop Mode Clock stop mode is a feature supported by Mobile DDR SDRAM devices. It reduces clock-related power consumption during idle periods of the device. Conditions: the Mobile DDR SDRAM supports clock stop in case: • The last access command (ACTIVE, READ, WRITE, PRECHARGE, AUTO REFRESH or MODE REGISTER SET) has executed to completion, including any data-out during read bursts; the number of required clock pulses per access command depends on the device's AC timing parameters and the clock frequency; • The related timing condition (tRCD, tWR, tRP, tRFC, tMRD) has been met; • CKE is held HIGH. When all conditions have been met, the device is either in ''idle'' or ''row active'' state, and clock stop mode may be entered with CK held LOW and /CK held HIGH. Clock stop mode is exited when the clock is restarted. NOPs command have to be issued for at least one clock cycle before the next access command may be applied. Additional clock pulses might be required depending on the system characteristics. Figure37 illustrates the clock stop mode: • Initially the device is in clock stop mode; • The clock is restarted with the rising edge of T0 and a NOP on the command inputs; • With T1 a valid access command is latched; this command is followed by NOP commands in order to allow for clock stop as soon as this access command has completed; • Tn is the last clock pulse required by the access command latched with T1. • The timing condition of this access command is met with the completion of Tn; therefore Tn is the last clock pulse required by this command and the clock is then stopped. Figure 37 : Clock Stop Mode T0 /CLK CLK CKE T1 Tn T2 High Timing Condition NOP CMD ADD CMD NOP NOP NOP Valide (High – Z) DQ,DQS Clock stopped Rev. A | Apr. 2012 Exit Clock Stop Mode Vail Command Enter Clock Stop Mode www.issi.com - [email protected] Don’t Care 40 IS43/46LR16800F Ordering Information – VDD = 1.8V Commercial Range: (0oC to +70oC) Configuration Frequency (MHz) Speed (ns) 8Mx16 166 6 Order Part No. Package IS43LR16800F-6BL 60-ball BGA, Lead-free Order Part No. Package IS43LR16800F-6BLI 60-ball BGA, Lead-free Industrial Range: (-40oC to +85oC) Configuration Frequency (MHz) Speed (ns) 8Mx16 166 6 Automotive Range, A1: (-40oC to +85oC) Configuration Frequency (MHz) Speed (ns) 8Mx16 166 6 Order Part No. Package IS46LR16800F-6BLA1 60-ball BGA, Lead-free Automotive Range, A2: (-40oC to +105oC) Configuration Frequency (MHz) Speed (ns) 8Mx16 166 6 Order Part No. Package IS46LR16800F-6BLA2 60-ball BGA, Lead-free Note: The -6 speed option supports -75 timing specifications. Rev. A | Apr. 2012 www.issi.com - [email protected] 41 IS43/46LR16800F Rev. A | Apr. 2012 www.issi.com - [email protected] 42