PRELIMINARY 256Mb: x32 SDRAM SYNCHRONOUS DRAM MT48LC8M32B2 - 2 Meg x 32 x 4 banks For the latest data sheet, please refer to the Micron Web site: www.micron.com/sdramds FEATURES • PC100 functionality • Fully synchronous; all signals registered on positive edge of system clock • Internal pipelined operation; column address can be changed every clock cycle • Internal banks for hiding row access/precharge • Programmable burst lengths: 1, 2, 4, 8, or full page • Auto Precharge, includes CONCURRENT AUTO PRECHARGE, and Auto Refresh Modes • Self Refresh Mode • 64ms, 4,096-cycle refresh (15.6µs/row) • LVTTL-compatible inputs and outputs • Single +3.3V ±0.3V power supply • Supports CAS latency of 1, 2, and 3 OPTIONS Pin Assignment (Top View) 86-Pin TSOP VDD DQ0 VDDQ DQ1 DQ2 VSSQ DQ3 DQ4 VDDQ DQ5 DQ6 VSSQ DQ7 NC VDD DQM0 WE# CAS# RAS# CS# A11 BA0 BA1 A10 A0 A1 A2 DQM2 VDD NC DQ16 VSSQ DQ17 DQ18 VDDQ DQ19 DQ20 VSSQ DQ21 DQ22 VDDQ DQ23 VDD MARKING • Configuration 8 Meg x 32 (2 Meg x 32 x 4 banks) 8M32B2 • Package 86-pin TSOP (400 mil) 86-pin TSOP (400 mil) Lead-free 90-ball FBGA (8mm x 13mm) 90-ball FBGA (8mm x 13mm) Lead-free • Timing (Cycle Time) 6ns (166 MHz) 7ns (143 MHz) TG P F5 1 B5 1 -6 -7 • Operating Temperature Range Commercial (0° to +70°C) Industrial (-40°C to +85°C) None IT 1 NOTE: 1. Available on -7 only Part Number Example: MT48LC8M32B2TG-7 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 VSS DQ15 VSSQ DQ14 DQ13 VDDQ DQ12 DQ11 VSSQ DQ10 DQ9 VDDQ DQ8 NC VSS DQM1 NC NC CLK CKE A9 A8 A7 A6 A5 A4 A3 DQM3 VSS NC DQ31 VDDQ DQ30 DQ29 VSSQ DQ28 DQ27 VDDQ DQ26 DQ25 VSSQ DQ24 VSS Note: The # symbol indicates signal is active LOW. KEY TIMING PARAMETERS SPEED GRADE -6 -7 CLOCK ACCESS TIME FREQUENCY CL = 3* 166 MHz 143 MHz 5.5ns 6.0ns SETUP TIME HOLD TIME 1.5ns 2ns 1ns 1ns 8 Meg x 32 Configuration Refresh Count *CL = CAS (READ) latency 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 1 2 Meg x 32 x 4 banks 4K Row Addressing Bank Addressing 4K (A0–A11) 4 (BA0, BA1) Column Addressing 512 (A0–A8) Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRODUCTS AND SPECIFICATIONS DISCUSSED HEREIN ARE FOR EVALUATION AND REFERENCE PURPOSES ONLY AND ARE SUBJECT TO CHANGE BY MICRON WITHOUT NOTICE. PRODUCTS ARE ONLY WARRANTED BY MICRON TO MEET MICRON’S PRODUCTION DATA SHEET SPECIFICATIONS. PRELIMINARY 256Mb: x32 SDRAM 90-Ball FBGA Assignment (Top View) 1 2 3 DQ26 DQ24 DQ28 4 5 6 7 8 9 VSS VDD DQ23 DQ21 VDDQ VSSQ VDDQ VSSQ DQ19 VSSQ DQ27 DQ25 DQ22 DQ20 VDDQ VSSQ DQ29 DQ30 DQ17 DQ18 VDDQ VDDQ DQ31 NC NC DQ16 VSSQ VSS DQM3 A3 A2 DQM2 VDD A4 A5 A6 A10 A0 A1 A7 A8 NC NC BA1 A11 CLK CKE A9 BA0 CS# RAS# DQM1 NC NC CAS# WE# DQM0 VDDQ DQ8 VSS VDD DQ7 VSSQ VSSQ DQ10 DQ9 DQ6 DQ5 VDDQ VSSQ DQ12 DQ14 DQ1 DQ3 VDDQ DQ11 VDDQ VSSQ VDDQ VSSQ DQ4 DQ13 DQ15 VSS VDD DQ0 DQ2 A B C D E F G H J K L M N P R 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 2 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM The SDRAM provides for programmable READ or WRITE burst lengths of 1, 2, 4, or 8 locations, or the full page, with a burst terminate option. An auto precharge function may be enabled to provide a self-timed row precharge that is initiated at the end of the burst sequence. The 256Mb SDRAM uses an internal pipelined architecture to achieve high-speed operation. This architecture is compatible with the 2n rule of prefetch architectures, but it also allows the column address to be changed on every clock cycle to achieve a highspeed, fully random access. Precharging one bank while accessing one of the other three banks will hide the precharge cycles and provide seamless, highspeed, random-access operation. The 256Mb SDRAM is designed to operate in 3.3V memory systems. An auto refresh mode is provided, along with a power-saving, power-down mode. All inputs and outputs are LVTTL-compatible. SDRAMs offer substantial advances in DRAM operating performance, including the ability to synchronously burst data at a high data rate with automatic column-address generation, the ability to interleave between internal banks to hide precharge time and the capability to randomly change column addresses on each clock cycle during a burst access. 256Mb (x32) SDRAM PART NUMBER PART NUMBER MT48LC8M32B2TG ARCHITECTURE 8 Meg x 32 GENERAL DESCRIPTION The 256Mb SDRAM is a high-speed CMOS, dynamic random-access memory containing 268,435,456-bits. It is internally configured as a quad-bank DRAM with a synchronous interface (all signals are registered on the positive edge of the clock signal, CLK). Each of the 67,108,864-bit banks is organized as 4,096 rows by 512 columns by 32 bits. Read and write accesses to the 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. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 3 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM TABLE OF CONTENTS Functional Block Diagram - 8 Meg x 32 ................. Pin Descriptions ........................................................... 5 6 Functional Description .......................................... Initialization ........................................................... Register Definition ................................................. Mode Register ................................................... Burst Length ................................................ Burst Type .................................................... CAS Latency ................................................ Operating Mode ......................................... Write Burst Mode ....................................... Commands .................................................................. Truth Table 1 (Commands and DQM Operation) ........... Command Inhibit ................................................. No Operation (NOP) ............................................ Load Mode Register ............................................... Active ....................................................................... Read ....................................................................... Write ....................................................................... Precharge ................................................................. Auto Precharge ....................................................... Burst Terminate ...................................................... Auto Refresh ........................................................... Self Refresh .............................................................. Operation .................................................................... Bank/Row Activation ........................................... Reads ....................................................................... Writes ....................................................................... Precharge ................................................................. Power-Down .......................................................... Clock Suspend ........................................................ Burst Read/Single Write ........................................ Concurrent Auto Precharge ................................. Write With Auto Precharge ................................. 9 9 9 9 9 10 11 11 11 12 12 13 13 13 13 13 13 13 13 14 14 14 15 15 16 22 24 24 25 25 26 27 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 Truth Table 2 (CKE) ..................................................... Truth Table 3 (Current State, Same Bank) ...................... Truth Table 4 (Current State, Different Bank) ................. 28 29 31 Absolute Maximum Ratings ...................................... 33 DC Electrical Characteristics and Operating Conditions ......................................... 33 IDD Specifications and Conditions ........................... 33 Capacitance .................................................................. 34 AC Electrical Characteristics (Timing Table) ..... 34 AC Functional Characteristics ............................ 35 Timing Waveforms Initialize and Load Mode Register ...................... Power-Down Mode ............................................... Clock Suspend Mode ............................................ Auto Refresh Mode ............................................... Self Refresh Mode .................................................. Reads Read – Single Read ........................................... Read – Without Auto Precharge ................... Read – With Auto Precharge .......................... Alternating Bank Read Accesses ..................... Read – Full-Page Burst ..................................... Read – DQM Operation ................................. Writes Write – Single Write ......................................... Write – Without Auto Precharge .................. Write – With Auto Precharge ........................ Alternating Bank Write Accesses ................... Write – Full-Page Burst .................................... Write – DQM Operation ................................ Package 86-Pin TSOP ...................................................... 90-Ball FBGA .................................................... 4 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM FUNCTIONAL BLOCK DIAGRAM 8 Meg x 32 SDRAM CKE CLK COMMAND DECODE CS# WE# CAS# RAS# CONTROL LOGIC BANK3 BANK2 BANK1 BANK0 MODE REGISTER REFRESH 12 COUNTER 12 ROWADDRESS MUX 12 12 BANK0 ROWADDRESS LATCH & DECODER 4096 BANK0 MEMORY ARRAY (4,096 x 512 x 32) 4 DQM0– DQM3 SENSE AMPLIFIERS 32 4,096 14 ADDRESS REGISTER 2 DATA OUTPUT REGISTER I/O GATING DQM MASK LOGIC READ DATA LATCH WRITE DRIVERS 2 A0–A11, BA0, BA1 4 BANK CONTROL LOGIC 32 32 512 (x32) DQ0– DQ31 DATA INPUT REGISTER COLUMN DECODER 89 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 COLUMNADDRESS COUNTER/ LATCH 9 5 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM PIN DESCRIPTIONS PIN NUMBERS DESCRIPTION 68 CLK Input Clock: CLK is driven by the system clock. All SDRAM input signals are sampled on the positive edge of CLK. CLK also increments the internal burst counter and controls the output registers. 67 CKE Input Clock Enable: CKE activates (HIGH) and deactivates (LOW) the CLK signal. Deactivating the clock provides PRECHARGE POWERDOWN and SELF REFRESH operation (all banks idle), ACTIVE POWER-DOWN (row active in any bank) or CLOCK SUSPEND operation (burst/access in progress). CKE is synchronous except after the device enters power-down and self refresh modes, where CKE becomes asynchronous until after exiting the same mode. The input buffers, including CLK, are disabled during power-down and self refresh modes, providing low standby power. CKE may be tied HIGH. 20 CS# Input 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. 17, 18, 19 WE#, CAS#, RAS# Input Command Inputs: WE# , CAS#, and RAS# (along with CS#) define the command being entered. 16, 71, 28, 59 DQM0– DQM3 Input Input/Output Mask: DQM is sampled HIGH and is an input mask signal for write accesses and an output enable signal for read accesses. Input data is masked during a WRITE cycle. The output buffers are placed in a High-Z state (two-clock latency) during a READ cycle. DQM0 corresponds to DQ0–DQ7, DQM1 corresponds to DQ8-DQ15, DQM2 corresponds to DQ16–DQ23 and DQM3 corresponds to DQ24–DQ31. DQM0–DQM3 are considered same state when referenced as DQM. 22, 23 25-27, 60-66, 24, 21 2, 74, 85, 40, SYMBOL TYPE 4, 5, 7, 8, 10, 11, 13, 76, 77, 79, 80, 82, 83, 31, 33, 34, 36, 37, 39, 42, 45, 47, 48, 50, 51, 53, 54, 56 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 BA0, BA1 Input A0-A11 DQ0– DQ31 Input Bank Address Input(s): BA0 and BA1 define to which bank the ACTIVE, READ, WRITE, or PRECHARGE command is being applied. Address Inputs: A0–A11 are sampled during the ACTIVE command (row-address A0–A10) and READ/WRITE command (column-address A0–A8 with A10 defining auto precharge) to select one location out of the memory array in the respective bank. A10 is sampled during a PRECHARGE command to determine if all banks are to be precharged (A10 [HIGH]) or bank selected by BA0, BA1 (LOW). The address inputs also provide the op-code during a LOAD MODE REGISTER command. Input/ Data I/Os: Data bus. Output 6 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM PIN DESCRIPTIONS (continued) PIN NUMBERS 14, 30, 57, 69, 70, 73 3, 9, 35, 41, 49, 55, 75, 81 6, 12, 32, 38, 46, 52, 78, 84 1, 15, 29, 43 44, 58, 72, 86 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 SYMBOL TYPE NC – VDDQ Supply V SS Q Supply VDD VSS Supply Supply DESCRIPTION No Connect: These pins should be left unconnected. Pin 70 is reserved for SSTL reference voltage supply. DQ Power Supply: Isolated on the die for improved noise immunity. DQ Ground: Provide isolated ground to DQs for improved noise immunity. Power Supply: +3.3V ±0.3V. Ground. 7 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM BALL DESCRIPTIONS 90-BALL FBGA SYMBOL TYPE J1 CLK Input Clock: CLK is driven by the system clock. All SDRAM input signals are sampled on the positive edge of CLK. CLK also increments the internal burst counter and controls the output registers. J2 CKE Input Clock Enable: CKE activates (HIGH) and deactivates (LOW) the CLK signal. Deactivating the clock provides PRECHARGE POWER-DOWN and SELF REFRESH operation (all banks idle), ACTIVE POWER-DOWN (row active in any bank) or CLOCK SUSPEND operation (burst/access in progress). CKE is synchronous except after the device enters power-down and self refresh modes, where CKE becomes asynchronous until after exiting the same mode. The input buffers, including CLK, are disabled during power-down and self refresh modes, providing low standby power. CKE may be tied HIGH. J8 CS# Input 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. J9, K7, K8 RAS#, CAS# WE# Input Command Inputs: RAS#, CAS#, and WE# (along with CS#) define the command being entered. K9, K1, F8, F2 DQM0–3 Input Input/Output Mask: DQM is sampled HIGH and is an input mask signal for write accesses and an output enable signal for read accesses. Input data is masked during a WRITE cycle. The output buffers are placed in a High-Z state (twoclock latency) when during a READ cycle. DQM0 corresponds to DQ0–DQ7, DQM1 corresponds to DQ8–DQ15, DQM2 corresponds to DQ16–DQ23 and DQM3 corresponds to DQ24–DQ31. DQM0-3 are considered same state when referenced as DQM. J7, H8 BA0, BA1 Input Bank Address Input(s): BA0 and BA1 define to which bank the ACTIVE, READ, WRITE or PRECHARGE command is being applied. These pins also provide the op-code during a LOAD MODE REGISTER command G8, G9, F7, F3, G1, G2, G3, H1, H2, J3, G7, H9 A0–A11 Input Address Inputs: A0–A11 are sampled during the ACTIVE command (rowaddress A0–A11) and READ/WRITE command (column-address A0–A8; with A10 defining auto precharge) to select one location out of the memory array in the respective bank. A10 is sampled during a PRECHARGE command to determine if all banks are to be precharged (A10 HIGH) or bank selected by BA0, BA1 (LOW). The address inputs also provide the op-code during a LOAD MODE REGISTER command. R8, N7, R9, N8, P9, M8, M7, L8, L2, M3, M2, P1, N2, R1, N3, R2, E8, D7, D8, B9, C8, A9, C7, A8, A2, C3, A1, C2, B1, D2, D3, E2 DQ0–DQ31 I/O E3, E7, H3, H7, K2, K3 NC – B2, B7, C9, D9, E1, L1, M9, N9, P2, P7 VDDQ Supply DQ Power: Provide isolated power to DQs for improved noise immunity. B8, B3, C1, D1, E9, L9, M1, N1, P3, P8 V SS Q Supply DQ Ground: Provide isolated ground to DQs for improved noise immunity. A7, F9, L7, R7 VDD Supply Power Supply: Voltage dependant on option. A3, F1, L3, R3 V SS Supply Ground. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 DESCRIPTION Data Input/Output: Data bus No Connect: These pins should be left unconnected. H3 is a not connect for this part but may be used as A12 in future designs. 8 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM FUNCTIONAL DESCRIPTION REGISTER DEFINITION In general, this 256Mb SDRAM (2 Meg x 32 x 4 banks) is a quad-bank DRAM that operates at 3.3V and includes a synchronous interface (all signals are registered on the positive edge of the clock signal, CLK). Each of the 67,108,864-bit banks is organized as 4,096 rows by 512 columns by 32-bits. Read and write accesses to the 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 and BA1 select the bank, A0–A11 select the row). The address bits (A0–A8) registered coincident with the READ or WRITE command are used to select the starting column location for the burst access. Prior to normal operation, the SDRAM must be initialized. The following sections provide detailed information covering device initialization, register definition, command descriptions and device operation. Mode Register The Mode Register is used to define the specific mode of operation of the SDRAM. This definition includes the selection of a burst length, a burst type, a CAS latency, an operating mode and a write burst mode, as shown in Figure 1. The Mode Register is programmed via the LOAD MODE REGISTER command and will retain the stored information until it is programmed again or the device loses power. Mode Register bits M0–M2 specify the burst length, M3 specifies the type of burst (sequential or interleaved), M4–M6 specify the CAS latency, M7 and M8 specify the operating mode, M9 specifies the write burst mode, and M10, M11, BA0, and BA1 are reserved for future use. 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 SDRAM are burst oriented, with the burst length being programmable, as shown in Figure 1. The burst length determines the maximum number of column locations that can be accessed for a given READ or WRITE command. Burst lengths of 1, 2, 4, or 8 locations are available for both the sequential and the interleaved burst types, and a fullpage burst is available for the sequential type. The full-page burst is used in conjunction with the BURST TERMINATE command to generate arbitrary burst lengths. 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; and by A3– A8 when the burst length is set to eight. The remaining (least significant) address bit(s) is (are) used to select the starting location within the block. Full-page bursts wrap within the page if the boundary is reached. INITIALIZATION SDRAMs must be powered up and initialized in a predefined manner. Operational procedures other than those specified may result in undefined operation. Once power is applied to VDD and VDDQ (simultaneously) and the clock is stable (stable clock is defined as a signal cycling within timing constraints specified for the clock pin), the SDRAM requires a 100µs delay prior to issuing any command other than a COMMAND INHIBIT or a NOP. Starting at some point during this 100µs period and continuing at least through the end of this period, COMMAND INHIBIT or NOP commands should be applied. Once the 100µs delay has been satisfied with at least one COMMAND INHIBIT or NOP command having been applied, a PRECHARGE command should be applied. All banks must then be precharged, thereby placing the device in the all banks idle state. Once in the idle state, two AUTO REFRESH cycles must be performed. After the AUTO REFRESH cycles are complete, the SDRAM is ready for Mode Register programming. Because the Mode Register will power up in an unknown state, it should be loaded prior to applying any operational command. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 9 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM 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 1. Table 1 Burst Definition Burst Length 2 Figure 1 Mode Register Definition 4 A11 11 A10 A9 10 9 A8 8 A6 A7 6 7 A5 5 A4 A3 4 Reserved* WB Op Mode CAS Latency 3 2 BT A1 A2 1 Address Bus A0 0 Mode Register (Mx) Burst length 8 *Should program M10, M11, BA0, BA1 = “0” to ensure compatibility with future devices. Burst Length M2 M1 M0 M3 = 0 M3 = 1 0 0 0 1 1 0 0 1 2 2 0 1 0 4 4 0 1 1 8 8 1 0 0 Reserved Reserved 1 0 1 Reserved Reserved 1 1 0 Reserved Reserved 1 1 1 Full Page Reserved Full Page (256) NOTE: Burst Type M3 0 Sequential 1 Interleave M6 M5 M4 CAS Latency 0 0 0 Reserved 0 0 1 1 0 1 0 2 0 1 1 3 1 0 0 Reserved 1 0 1 Reserved 1 1 0 Reserved 1 1 1 Reserved M8 M7 M6 - M0 Operating Mode 0 0 Defined Standard operation - - - M9 Write Burst Mode 0 Programmed Burst Length 1 Single Location Access 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 Starting Column Address A0 0 1 A1 A0 0 0 0 1 1 0 1 1 A2 A1 A0 0 0 0 0 0 1 0 1 0 0 1 1 1 0 0 1 0 1 1 1 0 1 1 1 Order of Accesses Within a Burst Type = Sequential Type = Interleaved 0-1 1-0 0-1 1-0 0-1-2-3 1-2-3-0 2-3-0-1 3-0-1-2 0-1-2-3 1-0-3-2 2-3-0-1 3-2-1-0 0-1-2-3-4-5-6-7 1-2-3-4-5-6-7-0 2-3-4-5-6-7-0-1 3-4-5-6-7-0-1-2 4-5-6-7-0-1-2-3 5-6-7-0-1-2-3-4 6-7-0-1-2-3-4-5 7-0-1-2-3-4-5-6 Cn, Cn + 1, Cn + 2 n = A0–A8 Cn + 3, Cn + 4... …Cn - 1, (Location 0 –256) Cn… 0-1-2-3-4-5-6-7 1-0-3-2-5-4-7-6 2-3-0-1-6-7-4-5 3-2-1-0-7-6-5-4 4-5-6-7-0-1-2-3 5-4-7-6-1-0-3-2 6-7-4-5-2-3-0-1 7-6-5-4-3-2-1-0 Not Supported 1. For a burst length of two, A1–A8 select the blockof-two burst; A0 selects the starting column within the block. 2. For a burst length of four, A2–A8 select the blockof-four burst; A0–A1 select the starting column within the block. 3. For a burst length of eight, A3–A8 select the blockof-eight burst; A0–A2 select the starting column within the block. 4. For a full-page burst, the full row is selected and A0–A8 select the starting column. 5. Whenever a boundary of the block is reached within a given sequence above, the following access wraps within the block. 6. For a burst length of one, A0–A8 select the unique column to be accessed, and mode register bit M3 is ignored. All other states reserved 10 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM CAS Latency The CAS latency is the delay, in clock cycles, between the registration of a READ command and the availability of the first piece of output data. The latency can be set to one, two or three clocks. If a READ command is registered at clock edge n, and the latency is m clocks, the data will be available by clock edge n + m. The DQs will start driving as a result of the clock edge one cycle earlier (n + m - 1), and provided that the relevant access times are met, the data will be valid by clock edge n + m. For example, assuming that the clock cycle time is such that all relevant access times are met, if a READ command is registered at T0 and the latency is programmed to two clocks, the DQs will start driving after T1 and the data will be valid by T2, as shown in Figure 2. Table 2 below indicates the operating frequencies at which each CAS latency setting can be used. Reserved states should not be used as unknown operation or incompatibility with future versions may result. Operating Mode The normal operating mode is selected by setting M7 and M8 to zero; the other combinations of values for M7 and M8 are reserved for future use and/or test modes. The programmed burst length applies to both READ and WRITE bursts. Test modes and reserved states should not be used because unknown operation or incompatibility with future versions may result. Write Burst Mode When M9 = 0, the burst length programmed via M0–M2 applies to both READ and WRITE bursts; when M9 = 1, the programmed burst length applies to READ bursts, but write accesses are single-location (nonburst) accesses. Figure 2 CAS Latency T0 T1 Table 2 CAS Latency T2 CLK COMMAND READ ALLOWABLE OPERATING FREQUENCY (MHz) NOP tLZ tOH DOUT DQ tAC SPEED -6 -7 CAS Latency = 1 T0 T1 T2 NOP NOP CAS LATENCY = 1 ≤ 50 ≤ 50 CAS LATENCY = 2 ≤ 100 ≤ 100 CAS LATENCY = 3 ≤ 166 ≤ 143 T3 CLK COMMAND READ tLZ tOH DOUT DQ tAC CAS Latency = 2 T0 T1 T2 T3 T4 NOP NOP NOP CLK COMMAND READ tLZ tOH DOUT DQ tAC CAS Latency = 3 DON’T CARE UNDEFINED 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 11 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM COMMANDS Truth Table 1 provides a quick reference of available commands. This is followed by a written description of each command. Three additional Truth Tables appear following the Operation section; these tables provide current state/next state information. TRUTH TABLE 1 – COMMANDS AND DQM OPERATION (Note: 1) NAME (FUNCTION) CS# RAS# CAS# WE# DQM ADDR DQs NOTES COMMAND INHIBIT (NOP) H X X X X X X NO OPERATION (NOP) L H H H X X X ACTIVE (Select bank and activate row) L L H H X Bank/Row X 3 H L/H 8 Bank/Col X 4 Bank/Col Valid 4 READ (Select bank and column, and start READ burst) L H L WRITE (Select bank and column, and start WRITE burst) L H L L L/H 8 BURST TERMINATE L H H L X X Active PRECHARGE (Deactivate row in bank or banks) L L H L X Code X 5 AUTO REFRESH or SELF REFRESH (Enter self refresh mode) L L L H X X X 6, 7 LOAD MODE REGISTER L L L L X Op-Code X 2 Write Enable/Output Enable – – – – L – Active 8 Write Inhibit/Output High-Z – – – – H – High-Z 8 NOTE: 1. 2. 3. 4. 5. 6. 7. 8. CKE is HIGH for all commands shown except SELF REFRESH. A0–A11 define the op-code written to the Mode Register. A0–A11 provide row address, BA0 and BA1 determine which bank is made active. A0–A8 provide column address; A10 HIGH enables the auto precharge feature (nonpersistent), while A10 LOW disables the auto precharge feature; BA0 and BA1 determine which bank is being read from or written to. A10 LOW: BA0 and BA1 determine the bank being precharged. A10 HIGH: All banks precharged and BA0 and BA1 are “Don’t Care.” This command is AUTO REFRESH if CKE is HIGH; SELF REFRESH if CKE is LOW. Internal refresh counter controls row addressing; all inputs and I/Os are “Don’t Care” except for CKE. Activates or deactivates the DQs during WRITEs (zero-clock delay) and READs (two-clock delay). DQM0 controls DQ0–DQ7; DQM1 controls DQ8–DQ15; DQM2 controls DQ16–DQ23; and DQM3 controls DQ24–DQ31. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 12 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM COMMAND INHIBIT The COMMAND INHIBIT function prevents new commands from being executed by the SDRAM, regardless of whether the CLK signal is enabled. The SDRAM is effectively deselected. Operations already in progress are not affected. WRITE The WRITE command is used to initiate a burst write access to an active row. The value on the BA0 and 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 DQM input logic level appearing coincident with the data. If a given DQM signal is registered LOW, the corresponding data will be written to memory; if the DQM signal is registered HIGH, the corresponding data inputs will be ignored, and a WRITE will not be executed to that byte/column location. NO OPERATION (NOP) The NO OPERATION (NOP) command is used to perform a NOP to an SDRAM which is selected (CS# is LOW). This prevents unwanted commands from being registered during idle or wait states. Operations already in progress are not affected. LOAD MODE REGISTER The mode register is loaded via inputs A0-A11. See mode register heading in the Register Definition section. The LOAD MODE REGISTER command can only be issued when all banks are idle, and a subsequent executable command cannot be issued until tMRD is met. 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. 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 and BA1 select the bank. Otherwise BA0 and 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. 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 and 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 and BA1 (B1) 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. Read data appears on the DQs subject to the logic level on the DQM inputs two clocks earlier. If a given DQMx signal was registered HIGH, the corresponding DQs will be High-Z two clocks later; if the DQMx signal was registered LOW, the corresponding DQs will provide valid data. DQM0 corresponds to DQ0–DQ7, DQM1 corresponds to DQ8–DQ15, DQM2 corresponds to DQ16– DQ23 and DQM3 corresponds to DQ24–DQ31. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 AUTO PRECHARGE Auto precharge is a feature which performs the same individual-bank PRECHARGE function described above, 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, except in the full-page burst mode, where auto precharge does not apply. Auto precharge is nonpersistent in that it is either enabled or disabled for each individual READ or WRITE command. Auto precharge ensures that the precharge is initiated at the earliest valid stage within a burst. The user must not issue another command to the same bank until the precharge time (tRP) is completed. This is determined as if an explicit PRECHARGE command was issued at the earliest possible time, as described for each burst type in the Operation section of this data sheet. 13 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM BURST TERMINATE The BURST TERMINATE command is used to truncate either fixed-length or full-page bursts. The most recently registered READ or WRITE command prior to the BURST TERMINATE command will be truncated, as shown in the Operation section of this data sheet. SELF REFRESH The SELF REFRESH command can be used to retain data in the SDRAM, even if the rest of the system is powered down. When in the self refresh mode, the SDRAM retains data without external clocking. The SELF REFRESH command is initiated like an AUTO REFRESH command except CKE is disabled (LOW). Once the SELF REFRESH command is registered, all the inputs to the SDRAM become “Don’t Care” with the exception of CKE, which must remain LOW. Once self refresh mode is engaged, the SDRAM provides its own internal clocking, causing it to perform its own AUTO REFRESH cycles. The SDRAM must remain in self refresh mode for a minimum period equal to tRAS and may remain in self refresh mode for an indefinite period beyond that. The procedure for exiting self refresh requires a sequence of commands. First, CLK must be stable (stable clock is defined as a signal cycling within timing constraints specified for the clock pin) prior to CKE going back HIGH. Once CKE is HIGH, the SDRAM must have NOP commands issued (a minimum of two clocks) for tXSR because time is required for the completion of any internal refresh in progress. Upon exiting SELF REFRESH mode, AUTO REFRESH commands must be issued every 15.625ms or less as both SELF REFRESH and AUTO REFRESH utililze the row refresh counter. AUTO REFRESH AUTO REFRESH is used during normal operation of the SDRAM and is analagous to CAS#-BEFORE-RAS# (CBR) REFRESH in conventional 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 “Don’t Care” during an AUTO REFRESH command. The 256Mb SDRAM requires 4,096 AUTO REFRESH cycles every 64ms (tREF), regardless of width option. Providing a distributed AUTO REFRESH command every 15.625µs will meet the refresh requirement and ensure that each row is refreshed. Alternatively, 4,096 AUTO REFRESH commands can be issued in a burst at the minimum cycle rate (tRFC), once every 64ms. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 14 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM OPERATION Figure 3 Activating a Specific Row in a Specific Bank BANK/ROW ACTIVATION Before any READ or WRITE commands can be issued to a bank within the 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. See Figure 3. After opening a row (issuing 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 issued. For example, a tRCD specification of 20ns with a 125 MHz clock (8ns period) results in 2.5 clocks, rounded to 3. This is reflected in Figure 4, which covers any case where 2 < tRCD (MIN)/tCK - 3. (The same procedure is used to convert other specification limits from time units to clock cycles.) A subsequent ACTIVE command to a different row in the same bank can only be issued after the previous active row has been “closed” (precharged). 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 t RRD. Example: Meeting tRCD CLK CKE HIGH CS# RAS# CAS# WE# ROW ADDRESS A0-A11 BANK ADDRESS BA0, BA1 Figure 4 (MIN) When 2 < tRCD (MIN)/tCK - 3 T0 T1 T2 T3 CLK tCK tCK COMMAND ACTIVE NOP tCK NOP READ or WRITE tRCD (MIN) tRCD (MIN) +0.5 tCK tRCD (MIN) = 20ns, tCK = 8ns tRCD (MIN) x tCK DON’T CARE where x = number of clocks for equation to be true. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 15 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM READs READ bursts are initiated with a READ command, as shown in Figure 5. The starting column and bank addresses are provided with the READ command, and auto precharge is either enabled or disabled for that burst access. If auto precharge is enabled, the row being accessed is precharged at the completion of the burst. For the generic READ commands used in the following illustrations, auto precharge is disabled. During READ bursts, the valid data-out element from the starting column address will be available following the CAS latency after the READ command. Each subsequent data-out element will be valid by the next positive clock edge. Figure 6 shows general timing for each possible CAS latency setting. Upon completion of a burst, assuming no other commands have been initiated, the DQs will go High-Z. A full-page burst will continue until terminated. (At the end of the page, it will wrap to column 0 and continue.) Data from any READ burst may be truncated with a subsequent READ command, and data from a fixedlength READ burst may be immediately followed by data from a READ command. In either case, a continuous flow of data can be maintained. The first data element from the new burst follows either the last element of a completed burst or the last desired data element of a longer burst that is being truncated. The new READ command should be issued x cycles before the clock edge at which the last desired data element is valid, where x equals the CAS latency minus one. This is shown in Figure 7 for CAS latencies of one, two and three; data Figure 5 READ Command Figure 6 CAS Latency CLK CKE T0 T1 T2 READ NOP CLK HIGH COMMAND tLZ CS# tOH DOUT DQ tAC CAS Latency = 1 RAS# CAS# T0 T1 T2 COMMAND WE# READ NOP NOP tLZ tOH DOUT DQ A0-A7 T3 CLK tAC COLUMN ADDRESS CAS Latency = 2 A8, A9, A11 ENABLE AUTO PRECHARGE A10 T0 T1 T2 T3 T4 READ NOP NOP NOP CLK DISABLE AUTO PRECHARGE COMMAND BA0,1 tLZ BANK ADDRESS tOH DOUT DQ tAC CAS Latency = 3 DON’T CARE UNDEFINED 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 16 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM element n + 3 is either the last of a burst of four or the last desired of a longer burst. This 256Mb SDRAM uses a pipelined architecture and therefore does not require the 2n rule associated with a prefetch architecture. A READ command can be initiated on any clock cycle following a previous READ command. Full-speed random read accesses can be performed to the same bank, as shown in Figure 8, or each subsequent READ may be performed to a different bank. Figure 7 Consecutive READ Bursts T0 T1 T2 T3 T4 T5 CLK COMMAND READ NOP NOP NOP READ NOP X = 0 cycles ADDRESS BANK, COL n BANK, COL b DOUT n DQ DOUT n+2 DOUT n+1 DOUT n+3 DOUT b CAS Latency = 1 T0 T1 T2 T3 T4 T5 T6 CLK COMMAND READ ADDRESS BANK, COL n NOP NOP NOP READ NOP NOP X = 1 cycle BANK, COL b DOUT n DQ DOUT n+2 DOUT n+1 DOUT n+3 DOUT b CAS Latency = 2 T0 T1 T2 T3 T4 T5 T6 T7 CLK COMMAND READ ADDRESS BANK, COL n NOP NOP NOP READ NOP NOP NOP X = 2 cycles BANK, COL b DOUT n DQ DOUT n+1 DOUT n+2 DOUT n+3 DOUT b CAS Latency = 3 NOTE: Each READ command may be to either bank. DQM is LOW. DON’T CARE 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 17 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM Figure 8 Random READ Accesses T0 T1 T2 T3 T4 CLK COMMAND READ READ READ READ ADDRESS BANK, COL n BANK, COL a BANK, COL x BANK, COL m DOUT n DQ NOP DOUT x DOUT a DOUT m CAS Latency = 1 T0 T1 T2 T3 T4 T5 CLK COMMAND READ READ READ READ ADDRESS BANK, COL n BANK, COL a BANK, COL x BANK, COL m DOUT n DQ NOP NOP DOUT x DOUT a DOUT m CAS Latency = 2 T0 T1 T2 T3 T4 T5 T6 CLK COMMAND READ READ READ READ ADDRESS BANK, COL n BANK, COL a BANK, COL x BANK, COL m NOP DOUT a DOUT n DQ NOP DOUT x NOP DOUT m CAS Latency = 3 NOTE: Each READ command may be to either bank. DQM is LOW. DON’T CARE 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 18 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM Data from any READ burst may be truncated with a subsequent WRITE command, and data from a fixedlength READ burst may be immediately followed by data from a WRITE command (subject to bus turnaround limitations). The WRITE burst may be initiated on the clock edge immediately following the last (or last desired) data element from the READ burst, provided that I/O contention can be avoided. In a given system design, there may be a possibility that the device driving the input data will go Low-Z before the SDRAM DQs go High-Z. In this case, at least a single-cycle delay should occur between the last read data and the WRITE command. The DQM input is used to avoid I/O contention, as shown in Figures 9 and 10. The DQM signal must be asserted (HIGH) at least two clocks prior to the WRITE command (DQM latency is two clocks for output buffers) to suppress data-out from the READ. Once the WRITE command is registered, the DQs will go High-Z (or remain High-Z), regardless of the state of the DQM signal; provided the DQM was active on the clock just prior to the WRITE command that truncated the READ command. If not, the second WRITE will be an invalid WRITE. For example, if DQM was low during T4 in Figure 10, then the WRITEs at T5 and T7 would be valid, while the WRITE at T6 would be invalid. The DQM signal must be de-asserted prior to the WRITE command (DQM latency is zero clocks for input buffers) to ensure that the written data is not masked. Figure 9 shows the case where the clock frequency allows for bus contention to be avoided without adding a NOP cycle, and Figure 10 shows the case where the additional NOP is needed. Figure 9 READ to WRITE T0 T1 T2 T3 T4 CLK DQM COMMAND READ ADDRESS BANK, COL n NOP NOP NOP Figure 10 READ to WRITE with Extra Clock Cycle WRITE BANK, COL b tCK tHZ T0 T1 T2 T3 T4 T5 CLK DOUT n DQ DIN b tDS DQM DON’T CARE NOTE: A CAS latency of three is used for illustration. The READ command may be to any bank, and the WRITE command may be to any bank. If a burst of one is used, then DQM is not required. COMMAND READ ADDRESS BANK, COL n NOP NOP NOP NOP WRITE BANK, COL b tHZ DQ DOUT n DIN b tDS DON’T CARE NOTE: 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 19 A CAS latency of three is used for illustration. The READ command may be to any bank, and the WRITE command may be to any bank. Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM A fixed-length READ burst may be followed by, or truncated with, a PRECHARGE command to the same bank (provided that auto precharge was not activated), and a full-page burst may be truncated with a PRECHARGE command to the same bank. The PRECHARGE command should be issued x cycles before the clock edge at which the last desired data element is valid, where x equals the CAS latency minus one. This is shown in Figure 11 for each possible CAS latency; data element n + 3 is either the last of a burst of four or the last desired of a longer burst. Following the PRECHARGE command, a subsequent command to the same bank cannot be issued until tRP is met. Note that part of the row precharge time is hidden during the access of the last data element(s). In the case of a fixed-length burst being executed to completion, a PRECHARGE command issued at the optimum time (as described above) provides the same Figure 11 READ to PRECHARGE T0 T1 T2 T3 T4 T5 T6 T7 CLK t RP COMMAND READ NOP NOP NOP PRECHARGE NOP NOP ACTIVE X = 0 cycles ADDRESS BANK (a or all) BANK a, COL n DOUT n DQ DOUT n+2 DOUT n+1 BANK a, ROW DOUT n+3 CAS Latency = 1 T0 T1 T2 T3 T4 T5 T6 T7 CLK t RP COMMAND READ NOP NOP NOP PRECHARGE NOP NOP ACTIVE X = 1 cycle ADDRESS BANK (a or all) BANK a, COL n DOUT n DQ BANK a, ROW DOUT n+2 DOUT n+1 DOUT n+3 CAS Latency = 2 T0 T1 T2 T3 T4 T5 T6 T7 CLK t RP COMMAND READ NOP NOP NOP PRECHARGE NOP NOP ACTIVE X = 2 cycles ADDRESS BANK (a or all) BANK a, COL n DOUT n DQ DOUT n+1 BANK a, ROW DOUT n+2 DOUT n+3 CAS Latency = 3 NOTE: DQM is LOW. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 DON’T CARE 20 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM operation that would result from the same fixed-length burst with auto precharge. The disadvantage of the PRECHARGE command is that it requires that the command and address buses be available at the appropriate time to issue the command; the advantage of the PRECHARGE command is that it can be used to truncate fixed-length or full-page bursts. Full-page READ bursts can be truncated with the BURST TERMINATE command, and fixed-length READ bursts may be truncated with a BURST TERMINATE command, provided that auto precharge was not activated. The BURST TERMINATE command should be issued x cycles before the clock edge at which the last desired data element is valid, where x equals the CAS latency minus one. This is shown in Figure 12 for each possible CAS latency; data element n + 3 is the last desired data element of a longer burst. Figure 12 Terminating a READ Burst T0 T1 T2 T3 T4 T5 T6 CLK COMMAND READ NOP NOP NOP BURST TERMINATE NOP NOP X = 0 cycles ADDRESS BANK, COL n DOUT n DQ DOUT n+2 DOUT n+1 DOUT n+3 CAS Latency = 1 T0 T1 T2 T3 T4 T5 T6 CLK COMMAND READ ADDRESS BANK, COL n NOP NOP NOP BURST TERMINATE NOP NOP X = 1 cycle DOUT n DQ DOUT n+2 DOUT n+1 DOUT n+3 CAS Latency = 2 T0 T1 T2 T3 T4 T5 T6 T7 CLK COMMAND READ ADDRESS BANK, COL n NOP NOP NOP BURST TERMINATE NOP NOP NOP X = 2 cycles DOUT n DQ DOUT n+1 DOUT n+2 DOUT n+3 CAS Latency = 3 NOTE: DQM is LOW. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 DON’T CARE 21 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM WRITEs WRITE bursts are initiated with a WRITE command, as shown in Figure 13. The starting column and bank addresses are provided with the WRITE command, and auto precharge is either enabled or disabled for that access. If auto precharge is enabled, the row being accessed is precharged at the completion of the burst. For the generic WRITE commands used in the following illustrations,auto precharge is disabled. During WRITE bursts, the first valid data-in element will be registered coincident with the WRITE command. Subsequent data elements will be registered on each successive positive clock edge. Upon completion of a fixed-length burst, assuming no other commands have been initiated, the DQs will remain High-Z and any additional input data will be ignored (see Figure 14). A full-page burst will continue until terminated. (At the end of the page, it will wrap to column 0 and continue.) Data for any WRITE burst may be truncated with a subsequent WRITE command, and data for a fixedlength WRITE burst may be immediately followed by data for a WRITE command. The new WRITE command can be issued on any clock following the previous WRITE command, and the data provided coincident with the new command applies to the new command. An example is shown in Figure 15. Data n + 1 is either the last of a burst of two or the last desired of a longer burst. This 256Mb SDRAM uses a pipelined architecture and therefore does not require the 2n rule associated with a prefetch architecture. A WRITE command can be initiated on any clock cycle following a previous WRITE command. Full-speed random write accesses within a page can be performed to the same bank, as shown in Figure 16, or each subsequent WRITE may be performed to a different bank. Figure 14 WRITE Burst T0 T1 T2 T3 COMMAND WRITE NOP NOP NOP ADDRESS BANK, COL n CLK Figure 13 WRITE Command DIN n DQ DIN n+1 CLK CKE HIGH Figure 15 WRITE to WRITE CS# T0 T1 T2 COMMAND WRITE NOP WRITE ADDRESS BANK, COL n RAS# CLK CAS# WE# A0-A7 COLUMN ADDRESS A8, A9, A11 DQ DIN n BANK, COL b DIN n+1 DIN b ENABLE AUTO PRECHARGE A10 TRANSITIONING DATA DISABLE AUTO PRECHARGE BA0,1 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 DON’T CARE NOTE: DQM is LOW. Each WRITE command may be to any bank. BANK ADDRESS 22 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM Data for any WRITE burst may be truncated with a subsequent READ command, and data for a fixedlength WRITE burst may be immediately followed by a READ command. Once the READ command is registered, the data inputs will be ignored, and WRITEs will not be executed. An example is shown in Figure 17. Data n + 1 is either the last of a burst of two or the last desired of a longer burst. Data for a fixed-length WRITE burst may be followed by, or truncated with, a PRECHARGE command to the same bank (provided that auto precharge was not activated), and a full-page WRITE burst may be truncated with a PRECHARGE command to the same bank. The PRECHARGE command should be issued tWR after the clock edge at which the last desired input data element is registered. The “two-clock” write-back requires at least one clock plus time, regardless of frequency, in auto precharge mode. In addition, when truncating a WRITE burst, the DQM signal must be used to mask input data for the clock edge prior to, and the clock edge coincident with, the PRECHARGE command. An example is shown in Figure 18. Data n + 1 is either the last of a burst of two or the last desired of a longer burst. Following the PRECHARGE command, a subsequent command to the same bank cannot be issued until tRP is met. The precharge will actually begin coincident with the clock-edge (T2 in Figure 18) on a “one-clock” tWR and sometime between the first and second clock on a “two-clock” tWR (between T2 and T3 in Figure 18.) In the case of a fixed-length burst being executed to completion, a PRECHARGE command issued at the optimum time (as described above) provides the same operation that would result from the same fixed-length burst with auto precharge. The disadvantage of the PRECHARGE command is that it requires that the command and address buses be available at the appropriate time to issue the command; the advantage of the PRECHARGE command is that it can be used to truncate fixed-length or full-page bursts. Figure 16 Random WRITE Cycles T0 T1 T2 T3 WRITE WRITE WRITE WRITE Figure 18 WRITE to PRECHARGE CLK COMMAND T0 T1 T2 T3 NOP PRECHARGE NOP T4 T5 T6 NOP ACTIVE NOP CLK ADDRESS BANK, COL n BANK, COL a BANK, COL x tWR = 1 CLK (tCK > tWR) BANK, COL m DQM DQ DIN n DIN a DIN x t RP DIN m COMMAND DON’T CARE ADDRESS WRITE BANK (a or all) BANK a, COL n BANK a, ROW t WR DQ Figure 17 WRITE to READ T0 T1 T2 T3 DIN n DIN n+1 tWR = 2 CLK (when tWR > tCK) T4 DQM T5 t RP CLK COMMAND COMMAND WRITE ADDRESS BANK, COL n NOP READ NOP NOP ADDRESS NOP WRITE NOP NOP PRECHARGE BANK (a or all) BANK a, COL n NOP NOP ACTIVE BANK a, ROW t WR DQ DIN n DQ BANK, COL b DOUT b DIN n+1 NOTE: DOUT b+1 DIN n DIN n+1 DQM could remain LOW in this example if the WRITE burst is a fixed length of two. DON’T CARE TRANSITIONING DATA 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 DON’T CARE 23 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM PRECHARGE The PRECHARGE command (Figure 20) 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 some specified time (tRP) after the PRECHARGE command is issued. 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 and BA1 select the bank. When all banks are to be precharged, inputs BA0 and 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. Fixed-length or full-page WRITE bursts can be truncated with the BURST TERMINATE command. When truncating a WRITE burst, the input data applied coincident with the BURST TERMINATE command will be ignored. The last data written (provided that DQM is LOW at that time) will be the input data applied one clock previous to the BURST TERMINATE command. This is shown in Figure 19, where data n is the last desired data element of a longer burst. Figure 19 Terminating a WRITE Burst T0 T1 T2 POWER-DOWN Power-down occurs if CKE is registered LOW coincident with a NOP or COMMAND INHIBIT when no accesses are in progress (see Figure 21). 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 either bank, this mode is referred to as active power-down. Entering power-down deactivates the input and output buffers, excluding CKE, for maximum power savings while in standby. The device may not remain in the power-down state longer than the refresh period (64ms) since no refresh operations are performed in this mode. The power-down state is exited by registering a NOP or COMMAND INHIBIT and CKE HIGH at the desired clock edge (meeting tCKS). CLK BURST TERMINATE NEXT COMMAND COMMAND WRITE ADDRESS BANK, COL n (ADDRESS) DIN n (DATA) DQ NOTE: DQMs are LOW. Figure 20 PRECHARGE Command Figure 21 Power-Down CLK CKE HIGH (( )) (( )) CLK tCKS CS# CKE RAS# > tCKS (( )) COMMAND (( )) (( )) NOP NOP All banks idle Input buffers gated off CAS# Enter power-down mode. WE# Exit power-down mode. ACTIVE tRCD tRAS tRC DON’T CARE A0-A9, A11 All Banks A10 Bank Selected BA0,1 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 BANK ADDRESS 24 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM CLOCK SUSPEND The clock suspend mode occurs when a column access/burst is in progress and CKE is registered LOW. In the clock suspend mode, the internal clock is deactivated, “freezing” the synchronous logic. For each positive clock edge on which CKE is sampled LOW, the next internal positive clock edge is suspended. Any command or data present on the input pins at the time of a suspended internal clock edge is ignored; any data present on the DQ pins remains driven; and burst counters are not incremented, as long as the clock is suspended. (See examples in Figures 22 and 23.) Clock suspend mode is exited by registering CKE HIGH; the internal clock and related operation will resume on the subsequent positive clock edge. BURST READ/SINGLE WRITE The burst read/single write mode is entered by programming the write burst mode bit (M9) in the Mode Register to a logic 1. In this mode, all WRITE commands result in the access of a single column location (burst of one), regardless of the programmed burst length. READ commands access columns according to the programmed burst length and sequence, just as in the normal mode of operation (M9 = 0). Figure 22 CLOCK SUSPEND During WRITE Burst T0 T1 T2 T3 T4 Figure 23 CLOCK SUSPEND During READ Burst T0 T5 T1 T2 T3 T4 T5 T6 CLK CLK CKE CKE INTERNAL CLOCK INTERNAL CLOCK COMMAND ADDRESS DIN NOP WRITE NOP ADDRESS BANK, COL n DQ DIN n+1 DIN n+2 NOP NOP NOP NOP NOP DOUT n DOUT n+1 DOUT n+2 DOUT n+3 DON’T CARE NOTE: For this example, CAS latency = 2, burst length = 4 or greater, and DQM is LOW. DON’T CARE 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 READ NOP BANK, COL n DIN n COMMAND 25 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM CONCURRENT AUTO PRECHARGE An access command to (READ or WRITE) another bank while an access command with auto precharge enabled is executing is not allowed by SDRAMs, unless the SDRAM supports CONCURRENT AUTO PRECHARGE. Micron SDRAMs support CONCURRENT AUTO PRECHARGE. Four cases where CONCURRENT AUTO PRECHARGE occurs are defined below. on bank n, CAS latency later. The PRECHARGE to bank n will begin when the READ to bank m is registered (Figure 24). 2. Interrupted by a WRITE (with or without auto precharge): A WRITE to bank m will interrupt a READ on bank n when registered. DQM should be used two clocks prior to the WRITE command to prevent bus contention. The PRECHARGE to bank n will begin when the WRITE to bank m is registered (Figure 25). READ with auto precharge 1. Interrupted by a READ (with or without auto precharge): A READ to bank m will interrupt a READ Figure 24 READ With Auto Precharge Interrupted by a READ T0 T1 T2 T3 T4 T5 T6 T7 CLK COMMAND NOP BANK n Internal States Page Active READ - AP BANK n READ - AP BANK m NOP READ with Burst of 4 NOP NOP NOP Idle Interrupt Burst, Precharge tRP - BANK m t RP - BANK n Page Active BANK m Precharge READ with Burst of 4 BANK n, COL a ADDRESS NOP BANK m, COL d DOUT a+1 DOUT a DQ DOUT d DOUT d+1 CAS Latency = 3 (BANK n) CAS Latency = 3 (BANK m) NOTE: DQM is LOW. Figure 25 READ With Auto Precharge Interrupted by a WRITE T0 T1 T2 T3 T4 T5 T6 T7 CLK COMMAND BANK n Internal States READ - AP BANK n Page Active NOP NOP NOP READ with Burst of 4 WRITE - AP BANK m NOP NOP Interrupt Burst, Precharge Idle tRP - BANK n Page Active BANK m ADDRESS NOP Write-Back WRITE with Burst of 4 BANK n, COL a t WR - BANK m BANK m, COL d 1 DQM DOUT a DQ DIN d DIN d+1 DIN d+2 DIN d+3 CAS Latency = 3 (BANK n) NOTE: 1. DQM is HIGH at T2 to prevent DOUT-a+1 from contending with DIN-d at T4. DON’T CARE 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 26 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM WRITE WITH AUTO PRECHARGE 3. Interrupted by a READ (with or without auto precharge): A READ to bank m will interrupt a WRITE on bank n when registered, with the data-out appearing CAS latency later. The PRECHARGE to bank n will begin after tWR is met, where tWR begins when the READ to bank m is registered. The last valid WRITE to bank n will be data-in registered one clock prior to the READ to bank m (Figure 26). 4. Interrupted by a WRITE (with or without auto precharge): A WRITE to bank m will interrupt a WRITE on bank n when registered. The PRECHARGE to bank n will begin after tWR is met, where tWR begins when the WRITE to bank m is registered. The last valid data WRITE to bank n will be data registered one clock prior to a WRITE to bank m (Figure 27). Figure 26 WRITE With Auto Precharge Interrupted by a READ T0 T1 T2 T3 T4 T5 T6 T7 CLK COMMAND BANK n Internal States NOP WRITE - AP BANK n Page Active READ - AP BANK m NOP WRITE with Burst of 4 DIN a DQ NOP Precharge tWR - BANK n tRP - BANK n NOP tRP - BANK m READ with Burst of 4 BANK n, COL a ADDRESS NOP Interrupt Burst, Write-Back Page Active BANK m NOP BANK m, COL d DOUT d+1 DOUT d DIN a+1 CAS Latency = 3 (BANK m) NOTE: 1. DQM is LOW. Figure 27 WRITE With Auto Precharge Interrupted by a WRITE T0 T1 T2 T3 T4 T5 T6 T7 CLK COMMAND BANK n Internal States NOP WRITE - AP BANK n Page Active NOP NOP WRITE with Burst of 4 NOP Interrupt Burst, Write-Back tWR - BANK n BANK m ADDRESS DQ Page Active BANK n, COL a DIN a NOP NOP Precharge tRP - BANK n t WR - BANK m Write-Back WRITE with Burst of 4 BANK m, COL d DIN a+1 DIN a+2 NOTE: 1. DQM is LOW. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 WRITE - AP BANK m DIN d DIN d+1 DIN d+2 DIN d+3 DON’T CARE 27 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM TRUTH TABLE 2 – CKE (Notes: 1-4) CKE n-1 CKE n L L L H H L H CURRENT STATE COMMAND n Power-Down X Maintain Power-Down Self Refresh X Maintain Self Refresh Clock Suspend X Maintain Clock Suspend Power-Down COMMAND INHIBIT or NOP Exit Power-Down 5 Self Refresh COMMAND INHIBIT or NOP Exit Self Refresh 6 Clock Suspend X Exit Clock Suspend 7 All Banks Idle COMMAND INHIBIT or NOP Power-Down Entry All Banks Idle AUTO REFRESH Self Refresh Entry Reading or Writing VALID H ACTION n NOTES Clock Suspend Entry See Truth Table 3 NOTE: 1. 2. 3. 4. 5. CKEn is the logic state of CKE at clock edge n; CKEn-1 was the state of CKE at the previous clock edge. Current state is the state of the SDRAM immediately prior to clock edge n. COMMANDn is the command registered at clock edge n, and ACTIONn is a result of COMMANDn. All states and sequences not shown are illegal or reserved. Exiting power-down at clock edge n will put the device in the all banks idle state in time for clock edge n + 1 (provided that tCKS is met). 6. Exiting self refresh at clock edge n will put the device in the all banks idle state once tXSR is met. COMMAND INHIBIT or NOP commands should be issued on any clock edges occurring during the tXSR period. A minimum of two NOP commands must be provided during tXSR period. 7. After exiting clock suspend at clock edge n, the device will resume operation and recognize the next command at clock edge n + 1. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 28 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM TRUTH TABLE 3 – CURRENT STATE BANK n, COMMAND TO BANK n (Notes: 1-6; notes appear below and on next page) CURRENT STATE Any CS# RAS# CAS# WE# COMMAND (ACTION) NOTES H X X X COMMAND INHIBIT (NOP/Continue previous operation) L H H H NO OPERATION (NOP/Continue previous operation) L L H H ACTIVE (Select and activate row) L L L H AUTO REFRESH 7 L L L L LOAD MODE REGISTER 7 L L H L PRECHARGE 11 L H L H READ (Select column and start READ burst) 10 L H L L WRITE (Select column and start WRITE burst) 10 L L H L PRECHARGE (Deactivate row in bank or banks) 8 Read L H L H READ (Select column and start new READ burst) 10 (Auto L H L L WRITE (Select column and start WRITE burst) 10 Precharge L L H L PRECHARGE (Truncate READ burst, start PRECHARGE) 8 Disabled) L H H L BURST TERMINATE 9 Write L H L H READ (Select column and start READ burst) 10 (Auto L H L L WRITE (Select column and start new WRITE burst) 10 Precharge L L H L PRECHARGE (Truncate WRITE burst, start PRECHARGE) 8 Disabled) L H H L BURST TERMINATE 9 Idle Row Active NOTE: 1. This table applies when CKEn-1 was HIGH and CKEn is HIGH (see Truth Table 2) and after tXSR has been met (if the previous state was self refresh). 2. This table is bank-specific, except where noted, i.e., the current state is for a specific bank and the commands shown are those allowed to be issued to that bank when in that state. Exceptions are covered in the notes below. 3. 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. 4. The following states must not be interrupted by a command issued to the same bank. COMMAND INHIBIT 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 Table 3, and according to Truth Table 4. Precharging: Starts with 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 w/Auto Precharge Enabled: Starts with registration of a READ command with auto precharge enabled and ends when tRP has been met. Once tRP is met, the bank will be in the idle state. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 29 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM NOTE (continued): Write w/Auto Precharge Enabled: 5. 6. 7. 8. 9. 10. 11. 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. The following states must not be interrupted by any executable command; COMMAND INHIBIT or NOP commands must be applied on each positive clock edge during these states. Refreshing: Starts with registration of an AUTO REFRESH command and ends when tRC is met. Once tRC is met, the SDRAM will be in the all banks idle state. Accessing Mode Register: Starts with registration of a LOAD MODE REGISTER command and ends when tMRD has been met. Once tMRD is met, the SDRAM will be in the all banks idle state. Precharging All: Starts with registration of a PRECHARGE ALL command and ends when tRP is met. Once tRP is met, all banks will be in the idle state. All states and sequences not shown are illegal or reserved. Not bank-specific; requires that all banks are idle. May or may not be bank-specific; if all banks are to be precharged, all must be in a valid state for precharging. Not bank-specific; BURST TERMINATE affects the most recent READ or WRITE burst, regardless of bank. READs or WRITEs listed in the Command (Action) column include READs or WRITEs with auto precharge enabled and READs or WRITEs with auto precharge disabled. Does not affect the state of the bank and acts as a NOP to that bank. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 30 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM TRUTH TABLE 4 – CURRENT STATE BANK n, COMMAND TO BANK m (Notes: 1-6; notes appear below and on next page) CURRENT STATE Any CS# RAS# CAS# WE# COMMAND (ACTION) NOTES H X X X COMMAND INHIBIT (NOP/Continue previous operation) L H H H NO OPERATION (NOP/Continue previous operation) Idle X X X X Any Command Otherwise Allowed to Bank m Row L L H H ACTIVE (Select and activate row) Activating, L H L H READ (Select column and start READ burst) 7 7 Active, or L H L L WRITE (Select column and start WRITE burst) Precharging L L H L PRECHARGE Read L L H H ACTIVE (Select and activate row) (Auto L H L H READ (Select column and start new READ burst) 7, 10 Precharge L H L L WRITE (Select column and start WRITE burst) 7, 11 Disabled) L L H L PRECHARGE Write L L H H ACTIVE (Select and activate row) (Auto L H L H READ (Select column and start READ burst) 7, 12 Precharge L H L L WRITE (Select column and start new WRITE burst) 7, 13 Disabled) L L H L PRECHARGE Read L L H H ACTIVE (Select and activate row) (With Auto L H L H READ (Select column and start new READ burst) 7, 8, 14 Precharge) L H L L WRITE (Select column and start WRITE burst) 7, 8, 15 L L H L PRECHARGE Write L L H H ACTIVE (Select and activate row) (With Auto L H L H READ (Select column and start READ burst) 7, 8, 16 Precharge) L H L L WRITE (Select column and start new WRITE burst) 7, 8, 17 L L H L PRECHARGE NOTE: 9 9 9 9 1. This table applies when CKEn-1 was HIGH and CKEn is HIGH (see Truth Table 2) and after tXSR has been met (if the previous state was self refresh). 2. This table describes alternate bank operation, except where noted; i.e., the current state is for bank n and the commands shown are those allowed to be issued to bank m (assuming that bank m is in such a state that the given command is allowable). Exceptions are covered in the notes below. 3. 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. Read w/Auto Precharge Enabled: Starts with registration of a READ command with auto precharge enabled, and ends when tRP has been met. Once tRP is met, the bank will be in the idle state. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 31 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM NOTE (continued): 4. AUTO REFRESH, SELF REFRESH, and LOAD MODE REGISTER commands may only be issued when all banks are idle. 5. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state only. 6. All states and sequences not shown are illegal or reserved. 7. READs or WRITEs to bank m listed in the Command (Action) column include READs or WRITEs with auto precharge enabled and READs or WRITEs with auto precharge disabled. 8. CONCURRENT AUTO PRECHARGE: Bank n will initiate the auto precharge command when its burst has been interrupted by bank m’s burst. 9. Burst in bank n continues as initiated. 10. For a READ without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the READ on bank n, CAS latency later (Figure 7). 11. For a READ without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt the READ on bank n when registered (Figures 9 and 10). DQM should be used one clock prior to the WRITE command to prevent bus contention. 12. For a WRITE without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the WRITE on bank n when registered (Figure 17), with the data-out appearing CAS latency later. The last valid WRITE to bank n will be data-in registered one clock prior to the READ to bank m. 13. For a WRITE without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt the WRITE on bank n when registered (Figure 15). The last valid WRITE to bank n will be data-in registered one clock prior to the READ to bank m. 14. For a READ with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the READ on bank n, CAS latency later. The PRECHARGE to bank n will begin when the READ to bank m is registered (Figure 24). 15. For a READ with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt the READ on bank n when registered. DQM should be used two clocks prior to the WRITE command to prevent bus contention. The PRECHARGE to bank n will begin when the WRITE to bank m is registered (Figure 25). 16. For a WRITE with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will interrupt the WRITE on bank n when registered, with the data-out appearing CAS latency later. The PRECHARGE to bank n will begin after tWR is met, where tWR begins when the READ to bank m is registered. The last valid WRITE to bank n will be data-in registered one clock prior to the READ to bank m (Figure 26). 17. For a WRITE with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will interrupt the WRITE on bank n when registered. The PRECHARGE to bank n will begin after tWR is met, where tWR begins when the WRITE to bank m is registered. The last valid WRITE to bank n will be data registered one clock prior to the WRITE to bank m (Figure 27). 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 32 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM ABOLUTE MAXIMUM RATINGS Voltage on VDD, VDDQ Supply Relative to VSS .............................................. -1V to +4.6V Voltage on Inputs, NC or I/O Pins Relative to VSS .............................................. -1V to +4.6V Operating Temperature, TA ............................ 0°C to +70°C Storage Temperature (plastic) ............ -55°C to +150°C Power Dissipation ........................................................ 1W Operating Temperature, TA (IT) ........... -40°C to +85°C *Stresses greater than those listed 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. DC ELECTRICAL CHARACTERISTICS AND OPERATING CONDITIONS (Notes: 1, 6; notes appear on page 36) (VDD, VDDQ = +3.3V ±0.3V) PARAMETER/CONDITION SYMBOL MIN MAX SUPPLY VOLTAGE VDD, VDDQ 3 3.6 V INPUT HIGH VOLTAGE: Logic 1; All inputs VIH 2 VDDQ+ 0.3 V 22 INPUT LOW VOLTAGE: Logic 0; All inputs VIL -0.3 0.8 V 22 II -5 5 µA OUTPUT LEAKAGE CURRENT: DQs are disabled; 0V ≤ VOUT ≤ VDDQ IOZ -5 5 µA OUTPUT LEVELS: Output High Voltage (IOUT = -4mA) Output Low Voltage (IOUT = 4mA) VOH 2.4 – V VOL – 0.4 V INPUT LEAKAGE CURRENT: Any input 0V ≤ VIN ≤ VDD (All other pins not under test = 0V) 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 33 UNITS NOTES Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM CAPACITANCE (Note: 2) PARAMETER SYMBOL MIN MAX UNITS Input Capacitance: CLK CI1 2.5 4.0 pF Input Capacitance: All other input-only pins CI2 2.5 4.0 pF Input/Output Capacitance: DQs CIO 4.0 6.5 pF ELECTRICAL CHARACTERISTICS AND RECOMMENDED AC OPERATING CONDITIONS (Notes: 5, 6, 8, 9, 11; notes appear on page 36) AC CHARACTERISTICS PARAMETER Access time from CLK (pos. edge) Address hold time Address setup time CLK high-level width CLK low-level width Clock cycle time -6 CL = 3 CL = 2 CL = 1 CL = 3 CL = 2 CL = 1 CKE hold time CKE setup time CS#, RAS#, CAS#, WE#, DQM hold time CS#, RAS#, CAS#, WE#, DQM setup time Data-in hold time Data-in setup time Data-out high-impedance time CL = 3 CL = 2 CL = 1 Data-out low-impedance time Data-out hold time ACTIVE to PRECHARGE command ACTIVE to ACTIVE command period AUTO REFRESH period ACTIVE to READ or WRITE delay Refresh period (4,096 rows) PRECHARGE command period ACTIVE bank a to ACTIVE bank b command Transition time WRITE recovery time Exit SELF REFRESH to ACTIVE command 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 SYMBOL tAC (3) tAC (2) tAC (1) t AH t AS tCH tCL tCK (3) tCK (2) tCK (1) tCKH tCKS tCMH tCMS t DH t DS tHZ (3) tHZ (2) tHZ (1) tLZ tOH tRAS tRC tRFC tRCD tREF t RP tRRD tT tWR tXSR MIN -7 MAX 5.5 7.5 17 1 1.5 2.5 2.5 6 10 20 1 1.5 1 1.5 1 1.5 MIN 1 2 2.75 2.75 7 10 20 1 2 1 2 1 2 5.5 7.5 17 1 2 42 60 60 18 120K 6 8 17 1 2.5 42 70 70 20 64 18 12 0.3 1CLK+ 6ns 12ns 70 34 MAX 6 8 17 1.2 120K 64 20 14 0.3 1CLK+ 7ns 14ns 70 1.2 UNITS ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ms ns ns ns tCK NOTES ns ns 27 20 23 23 23 10 10 10 25 7 24 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM AC FUNCTIONAL CHARACTERISTICS (Notes: 5, 6, 7, 8, 9, 11; notes appear on page 36) PARAMETER READ/WRITE command to READ/WRITE command CKE to clock disable or power-down entry mode CKE to clock enable or power-down exit setup mode DQM to input data delay DQM to data mask during WRITEs DQM to data high-impedance during READs WRITE command to input data delay Data-in to ACTIVE command SYMBOL tCCD tCKED t PED t DQD tDQM t DQZ t DWD tDAL (3) tDAL (2) tDAL (1) tDPL tBDL tCDL tRDL tMRD tROH (3) tROH (2) tROH (1) CL = 3 CL = 2 CL = 1 Data-in to PRECHARGE command Last data-in to burst STOP command Last data-in to new READ/WRITE command Last data-in to PRECHARGE command LOAD MODE REGISTER command to ACTIVE or REFRESH command Data-out to high-impedance from PRECHARGE command CL = 3 CL = 2 CL = 1 -6 1 1 1 0 0 2 0 5 4 3 2 1 1 2 2 3 2 1 -7 1 1 1 0 0 2 0 5 4 3 2 1 1 2 2 3 2 1 UNITS tCK tCK tCK tCK tCK tCK tCK tCK tCK tCK tCK tCK tCK tCK tCK tCK tCK tCK NOTES 17 14 14 17 17 17 17 15, 21 15, 21 15, 21 16, 21 17 17 16, 21 26 17 17 17 IDD SPECIFICATIONS AND CONDITIONS (Notes: 1, 6, 11, 13; notes appear on page 36) (VDD, VDDQ = +3.3V ±0.3V) MAX PARAMETER/CONDITION SYMBOL IDD1 Operating Current: Active Mode; Burst = 2; READ or WRITE; t RC = tRC (MIN) Standby Current: Power-Down Mode; All banks idle; CKE IDD2N = LOW Standby Current: Power-Down Mode; All banks idle; CKE IDD2NS = HIGH Standby Current: Active Mode; CKE = HIGH; CS# = HIGH; IDD3NS All banks active after tRCD met; No accesses in progress IDD3N Standby Current: Active Mode; CKE = LOW; CS# = HIGH; All banks active; No accesses in progress IDD4 Operating Current: Burst Mode; Continuous burst; READ or WRITE; All banks active, half DQs toggling every cycle. tRFC = tRFC IDD5 Auto Refresh Current CKE = HIGH; CS# = HIGH (MIN) tRFC = IDD6 -6 -7 210 190 mA 300 300 µA 30 30 mA 40 40 mA 30 30 mA 165 145 mA 3, 18, 19, 26 335 295 mA 3, 12, 18, 19, 26 3 mA 3 UNITS NOTES 3, 18, 19, 26 3, 12, 19, 26 15.625µs SELF REFRESH current: CKE < 0.2V 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 IDD7 35 1 1 mA Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM NOTES 1. 2. 3. 4. 5. 6. 7. 8. All voltages referenced to VSS. This parameter is sampled. VDD, VDD Q = +3.3V; f = 1 MHz, TA = 25°C; pin under test biased at 1.4V. AC can range from 0pF to 6pF. IDD is dependent on output loading and cycle rates. Specified values are obtained with minimum cycle time and the outputs open. Enables on-chip refresh and address counters. The minimum specifications are used only to indicate cycle time at which proper operation over the full temperature range (0°C ≤ T A ≤ +70°C and -40°C ≤ TA ≤ +85°C for IT parts) is ensured. An initial pause of 100µs is required after powerup, followed by two AUTO REFRESH commands, before proper device operation is ensured. (VDD and VDDQ must be powered up simultaneously. VSS and VSSQ must be at same potential.) The two AUTO REFRESH command wake-ups should be repeated any time the tREF refresh requirement is exceeded. AC characteristics assume tT = 1ns. In addition to meeting the transition rate specification, the clock and CKE must transit between VIH and VIL (or between VIL and VIH) in a monotonic manner. 12. Other input signals are allowed to transition no more than once in any two-clock period and are otherwise at valid VIH or VIL levels. 13. IDD specifications are tested after the device is properly initialized. 14. Timing actually specified by tCKS; clock(s) specified as a reference only at minimum cycle rate. 15. Timing actually specified by tWR plus tRP; clock(s) specified as a reference only at minimum cycle rate. 16. Timing actually specified by tWR. 17. Required clocks are specified by JEDEC functionality and are not dependent on any timing parameter. 18. The IDD current will decrease as the CAS latency is reduced. This is due to the fact that the maximum cycle rate is slower as the CAS latency is reduced. 19. Address transitions average one transition every two clocks. 20. CLK must be toggled a minimum of two times during this period. 21. Based on tCK = 143 MHz for -7, 166 MHz for -6. 22. VIH overshoot: VIH (MAX) = VDDQ + 1.2V for a pulse width ≤ 3ns, and the pulse width cannot be greater than one third of the cycle rate. VIL undershoot: VIL (MIN) = -1.2V for a pulse width ≤ 3ns, and the pulse width cannot be greater than one third of the cycle rate. 23. The clock frequency must remain constant during access or precharge states (READ, WRITE, including tWR, and PRECHARGE commands). CKE may be used to reduce the data rate. 24. Auto precharge mode only. 25. JEDEC and PC100 specify three clocks. 26. tCK = 7ns for -7, 6ns for -6. 27. Check factory for availability of specially screened devices having tWR = 10ns. tWR = 1 tCK for 100 MHz and slower ( tCK = 10ns and higher) in manual precharge. Q 30pF 9. Outputs measured at 1.5V with equivalent load: 10. tHZ defines the time at which the output achieves the open circuit condition; it is not a reference to VOH or VOL. The last valid data element will meet tOH before going High-Z. 11. AC timing and IDD tests have VIL = .25 and VIH = 2.75, with timing referenced to 1.5V crossover point. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 36 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM INITIALIZE AND LOAD MODE REGISTER T0 CLK (( )) tCKS tCK T1 Tn + 1 (( )) (( )) tCKH tCH (( )) (( )) To + 1 tCL (( )) (( )) (( )) (( )) (( )) (( )) (( )) COMMAND (( )) (( )) DQM 0-3 (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) A0-A9, A11 (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) A10 (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) BA0, BA1 DQ NOP SINGLE BANK ALL BANKS High-Z Power-up: VDD and CK stable Tp + 3 tCMS tCMH (( )) PRECHARGE (( )) ALL BANKS (( )) (( )) (( )) T = 100µs (MIN) tCMS tCMH Tp + 2 (( )) CKE tCMS tCMH Tp + 1 AUTO REFRESH (( )) NOP NOP (( )) AUTO REFRESH (( )) NOP NOP (( )) LOAD MODE REGISTER tAS NOP tAH ROW CODE tAS ACTIVE tAH ROW CODE BANK (( )) tRP Precharge all banks tRFC tRFC AUTO REFRESH AUTO REFRESH tMRD Program Mode Register 1, 2 DON’T CARE UNDEFINED NOTE: 1. The Mode Register may be loaded prior to the AUTO REFRESH cycles if desired. 2. Outputs are guaranteed High-Z after command is issued. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 37 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM POWER-DOWN MODE1 T0 T1 tCK CLK T2 tCKS tCH CKE tCKS PRECHARGE Tn + 2 tCKS (( )) tCKH tCMS tCMH COMMAND Tn + 1 (( )) (( )) tCL NOP (( )) (( )) NOP NOP ACTIVE DQM 0-3 (( )) (( )) A0-A9, A11 (( )) (( )) ROW (( )) (( )) ROW (( )) (( )) BANK ALL BANKS A10 SINGLE BANK tAS BA0, BA1 tAH BANK(S) High-Z (( )) DQ Two clock cycles Input buffers gated off while in power-down mode Precharge all active banks All banks idle, enter power-down mode All banks idle Exit power-down mode DON’T CARE UNDEFINED NOTE: 1. Violating refresh requirements during power-down may result in a loss of data. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 38 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM CLOCK SUSPEND MODE1 T0 T1 tCK CLK T2 T3 T4 T5 T6 T7 T8 NOP WRITE T9 tCL tCH tCKS tCKH CKE tCKS tCKH tCMS tCMH COMMAND READ NOP NOP NOP NOP NOP tCMS tCMH DQM0-3 tAS A0-A9, A11 tAH COLUMN m 2 tAS COLUMN e 2 tAH A10 tAS BA0, BA1 tAH BANK BANK tAC tOH tAC DQ tLZ DOUT m tHZ DOUT m + 1 tDS tDH DOUT e DOUT e + 1 DON’T CARE UNDEFINED NOTE: 1. For this example, the burst length = 2, the CAS latency = 3, and auto precharge is disabled. 2. A9 and A11 = “Don’t Care.” 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 39 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM AUTO REFRESH MODE T0 CLK T1 tCK T2 (( )) (( )) tCH tCKS tCKH tCMS tCMH PRECHARGE NOP AUTO REFRESH NOP (( )) ( ( NOP )) NOP (( )) ( ( NOP )) ACTIVE (( )) (( )) (( )) (( )) ROW (( )) (( )) (( )) (( )) ROW (( )) (( )) (( )) (( )) BANK (( )) (( )) ALL BANKS A10 SINGLE BANK DQ AUTO REFRESH (( )) (( )) A0-A9, A11 tAS To + 1 (( )) (( )) (( )) DQM 0-3 BA0, BA1 (( )) (( )) (( )) CKE COMMAND Tn + 1 tCL tAH BANK(S) High-Z tRP tRFC tRFC Precharge all active banks 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 DON’T CARE 40 UNDEFINED DON’T CARE Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM SELF REFRESH MODE T0 CLK T1 tCK tCL tCH T2 tCKS > tRAS CKE COMMAND tCKS tCKH tCMS tCMH PRECHARGE Tn + 1 (( )) (( )) (( )) (( )) (( )) NOP AUTO REFRESH (( )) (( )) (( )) (( )) (( )) (( )) (( )) A0-A9, A11 (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) (( )) SINGLE BANK tAS BA0, BA1 DQ AUTO REFRESH )) (( )) (( )) ALL BANKS To + 2 tCKS NOP ( ( DQM 0-3 A10 To + 1 tAH BANK(S) High-Z tRP Precharge all active banks tXSR Enter self refresh mode Exit self refresh mode (Restart refresh time base) CLK stable prior to exiting self refresh mode 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 41 DON’T CARE UNDEFINED Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM SINGLE READ – WITHOUT AUTO PRECHARGE1 T0 T1 T2 tCK CLK T3 T4 T5 NOP ACTIVE tCL tCH tCKS tCKH tCMS tCMH CKE COMMAND ACTIVE NOP READ tCMS PRECHARGE tCMH DQM / DQML, DQMH tAS A0-A9, A11 COLUMN m2 ROW tAS ROW tAH ALL BANKS ROW A10 tAS BA0, BA1 tAH ROW DISABLE AUTO PRECHARGE tAH BANK SINGLE BANK BANK BANK BANK tAC DQ tLZ tRCD tOH DOUT m tHZ CAS Latency tRP tRAS tRC DON’T CARE NOTE: 1. For this example, the burst length = 1, the CAS latency = 2, and the READ burst is followed by a “manual” PRECHARGE. 2. A9 and A11 = “Don’t Care.” 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 42 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM READ – WITHOUT AUTO PRECHARGE1 T0 T1 tCK CLK T2 T3 T4 T5 NOP NOP T6 T7 T8 NOP ACTIVE tCL tCH tCKS tCKH tCMS tCMH CKE COMMAND ACTIVE NOP READ tCMS NOP PRECHARGE tCMH DQM 0-3 tAS COLUMN m 2 ROW A0-A9, A11 tAS ROW tAH ALL BANKS ROW A10 tAS BA0, BA1 tAH ROW SINGLE BANK DISABLE AUTO PRECHARGE tAH BANK BANK BANK tAC tOH tAC DQ tLZ tRCD DOUT m tAC tOH DOUT m + 1 BANK tAC tOH tOH DOUT m + 2 DOUT m + 3 tHZ tRP CAS Latency tRAS tRC DON’T CARE UNDEFINED NOTE: 1. For this example, the burst length = 4, the CAS latency = 2, and the READ burst is followed by a “manual” PRECHARGE. 2. A9 and A11 = “Don’t Care.” 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 43 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM READ – WITH AUTO PRECHARGE1 T0 T1 tCK CLK tCKS T2 T3 T4 T5 NOP NOP T6 T7 T8 NOP ACTIVE tCL tCH tCKH CKE tCMS tCMH COMMAND ACTIVE NOP READ tCMS NOP NOP tCMH DQM 0-3 tAS A0-A9, A11 tAH ROW ENABLE AUTO PRECHARGE ROW tAS BA0, BA1 COLUMN m 2 ROW tAS A10 tAH ROW tAH BANK BANK BANK tAC tOH tAC DQ tLZ tRCD DOUT m tAC tAC tOH tOH tOH DOUT m + 1 DOUT m + 2 DOUT m + 3 tHZ tRP CAS Latency tRAS tRC DON’T CARE UNDEFINED NOTE: 1. For this example, the burst length = 4, and the CAS latency = 2. 2. A9 and A11 = “Don’t Care.” 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 44 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM ALTERNATING BANK READ ACCESSES1 T0 T1 tCK CLK T2 T3 T4 T5 NOP ACTIVE T6 T7 T8 READ NOP ACTIVE tCL tCH tCKS tCKH tCMS tCMH CKE COMMAND ACTIVE NOP READ tCMS NOP tCMH DQM 0-3 tAS A0-A9, A11 tAH COLUMN b 2 ROW ENABLE AUTO PRECHARGE ROW ENABLE AUTO PRECHARGE ROW tAS BA0, BA1 COLUMN m 2 ROW tAS A10 tAH ROW ROW tAH BANK 0 BANK 0 BANK 4 tAC tOH tAC DQ tLZ tRCD - BANK 0 BANK 4 DOUT m tAC tOH DOUT m + 1 BANK 0 tAC tOH DOUT m + 2 tAC tOH DOUT m + 3 tRP - BANK 0 CAS Latency - BANK 0 tAC tOH DOUT b tRCD - BANK 0 tRAS - BANK 0 tRC - BANK 0 tRCD - BANK 4 tRRD CAS Latency - BANK 4 DON’T CARE UNDEFINED NOTE: 1. For this example, the burst length = 4, and the CAS latency = 2. 2. A9 and A11 = “Don’t Care.” 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 45 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM READ – FULLL-PAGE BURST1 T0 T1 T2 tCL CLK T3 T4 T5 T6 (( )) (( )) tCK tCH tCKS tCMH ACTIVE NOP READ tCMS NOP NOP NOP NOP tCMH tAS tAH tAH NOP BURST TERM NOP NOP (( )) (( )) ROW tAS (( )) (( )) (( )) (( )) COLUMN m 2 ROW tAS BA0, BA1 Tn + 4 (( )) (( )) DQM 0-3 A10 Tn + 3 (( )) (( )) tCMS A0-A9, A11 Tn + 2 tCKH CKE COMMAND Tn + 1 tAH BANK (( )) (( )) BANK tAC tAC tOH Dout m DQ DOUT m+1 tLZ tRCD CAS Latency tAC tOH tAC ( ( )) tOH (( )) DOUT m+2 (( )) tAC tOH DOUT m-1 tAC tOH DOUT m tOH DOUT m+1 tHZ 256 locations within same row Full page completed Full-page burst does not self-terminate. 3 Can use BURST TERMINATE command. DON’T CARE UNDEFINED NOTE: 1. For this example, the CAS latency = 2. 2. A9 and A11 = “Don’t Care.” 3. Page left open; no tRP. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 46 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM READ – DQM OPERATION1 T0 T1 tCK CLK tCKS tCKH tCMS tCMH T2 T3 T4 T5 NOP NOP T6 T7 T8 NOP NOP NOP tCL tCH CKE COMMAND ACTIVE NOP READ tCMS NOP tCMH DQM 0-3 tAS A0-A9, A11 tAH ENABLE AUTO PRECHARGE ROW tAS BA0, BA1 COLUMN m 2 ROW tAS A10 tAH DISABLE AUTO PRECHARGE tAH BANK BANK tAC DQ tOH DOUT m tLZ tRCD tAC tHZ tAC tOH DOUT m + 2 tLZ tOH DOUT m + 3 tHZ CAS Latency DON’T CARE UNDEFINED NOTE: 1. For this example, the CAS latency = 2. 2. A9 and A11 = “Don’t Care.” 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 47 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM SINGLE WRITE T0 tCK CLK T1 T2 tCL T3 T4 T5 T6 tCH tCKS tCKH tCMS tCMH CKE COMMAND ACTIVE NOP WRITE NOP PRECHARGE NOP ACTIVE tCMS tCMH DQM / DQML, DQMH tAS A0-A9, A11 ROW tAH ALL BANKS ROW tAS BA0, BA1 COLUMN m 3 ROW tAS A10 tAH ROW DISABLE AUTO PRECHARGE tAH BANK SINGLE BANK BANK tDS BANK BANK tDH DIN m DQ tRCD tRAS t WR 2 tRP tRC DON’T CARE NOTE: 1. For this example, the burst length = 1, and the WRITE burst is followed by a “manual” PRECHARGE. 2. tWR is required between <DIN m> and the PRECHARGE command, regardless of frequency. 3. A9 and A11 = “Don’t Care.” 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 48 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM WRITE – WITHOUT AUTO PRECHARGE1 T0 tCK CLK T1 T2 tCL T3 T4 T5 T6 NOP NOP NOP T7 T8 NOP ACTIVE tCH tCKS tCKH tCMS tCMH CKE COMMAND ACTIVE NOP WRITE PRECHARGE tCMS tCMH DQM 0-3 tAS A0-A9, A11 ROW tAH ALL BANKs ROW tAS BA0, BA1 COLUMN m 3 ROW tAS A10 tAH ROW tAH DISABLE AUTO PRECHARGE SINGLE BANK BANK BANK BANK tDS tDH DIN m DQ tDS tDH DIN m + 1 tDS tDH DIN m + 2 tDS tDH DIN m + 3 t WR 2 tRCD tRAS BANK tRP tRC DON T CARE NOTE: 1. 2. 3. 4. For this example, the burst length = 4, and the WRITE burst is followed by a “manual” PRECHARGE. Faster frequencies require two clocks (when tWR > tCK). A9 and A11 = “Don’t Care.” t WR of 1 CLK available if running 100 MHz or slower. Check factory for availability. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 49 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM WRITE – WITH AUTO PRECHARGE1 T0 tCK CLK tCKS tCKH tCMS tCMH T1 T2 tCL T3 T4 T5 T6 T7 T8 T9 NOP NOP NOP NOP NOP NOP ACTIVE tCH CKE COMMAND ACTIVE NOP WRITE tCMS tCMH DQM 0-3 tAS A0-A9, A11 tAH ROW ENABLE AUTO PRECHARGE ROW tAS BA0, BA1 COLUMN m 3 ROW tAS A10 tAH ROW tAH BANK BANK tDS tDH DIN m DQ BANK tDS tDH DIN m + 1 tDS tDH DIN m + 2 tDS tDH DIN m + 3 tWR 2 tRCD tRAS tRP tRC DON’T CARE NOTE: 1. For this example, the burst length = 4. 2. Faster frequencies require two clocks (when tWR > tCK). 3. A9 and A11 = “Don’t Care.” 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 50 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM ALTERNATING BANK WRITE ACCESSES1 T0 tCK CLK T1 T2 tCL T3 T4 T5 T6 T7 T8 T9 NOP NOP ACTIVE tCH tCKS tCKH tCMS tCMH CKE COMMAND ACTIVE NOP WRITE tCMS NOP ACTIVE NOP WRITE tCMH DQM 0-3 tAS A0-A9, A11 tAS A10 COLUMN m 3 tAH COLUMN b 3 ROW ENABLE AUTO PRECHARGE ROW ENABLE AUTO PRECHARGE ROW tAS BA0, BA1 tAH ROW ROW ROW tAH BANK 0 BANK 0 tDS tDH DIN m DQ BANK 1 tDS tDH DIN m + 1 tDS BANK 1 tDH tDS DIN m + 2 tDH DIN m + 3 tDS tDH DIN b tWR2 - BANK 0 tRCD - BANK 0 BANK 0 tDS tDH DIN b + 1 tRP - BANK 0 tDS tDH DIN b + 2 tDS tDH DIN b + 3 tRCD - BANK 0 tRAS - BANK 0 tRC - BANK 0 tRRD tRCD - BANK 4 tWR - BANK 4 DON’T CARE NOTE: 1. For this example, the burst length = 4. 2. Faster frequencies require two clocks (when tWR > tCK). 3. A9 and A11 = “Don’t Care.” 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 51 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM WRITE – FULL-PAGE BURST T0 T1 T2 tCL CLK T3 T4 T5 (( )) (( )) tCK tCH tCKS tCKH COMMAND tCMH ACTIVE NOP WRITE NOP NOP NOP tCMS tCMH A0-A9, A11 tAS A10 (( )) (( )) NOP BURST TERM NOP (( )) (( )) COLUMN m 1 tAH (( )) (( )) ROW tAS BA0, BA1 tAH ROW Tn + 3 (( )) (( )) DQM 0-3 tAS Tn + 2 (( )) (( )) CKE tCMS Tn + 1 tAH BANK (( )) (( )) BANK tDS tDH DIN m DQ tDS tDH tDS DIN m + 1 tDH DIN m + 2 tRCD tDS tDH DIN m + 3 (( )) (( )) tDS tDH DIN m - 1 256 locations within same row Full-page burst does not self-terminate. Can use BURST TERMINATE command to stop.2, 3 Full page completed NOTE: 1. A9 and A11 = “Don’t Care.” 2. tWR must be satisfied prior to PRECHARGE command. 3. Page left open; no tRP. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 52 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM WRITE – DQM OPERATION1 T0 T1 tCK CLK T2 T3 T4 T5 NOP NOP NOP T6 T7 NOP NOP tCL tCH tCKS tCKH tCMS tCMH CKE COMMAND ACTIVE NOP WRITE tCMS tCMH DQM 0-3 tAS A0-A9, A11 tAH ENABLE AUTO PRECHARGE ROW tAS BA0, BA1 COLUMN m 2 ROW tAS A10 tAH tAH DISABLE AUTO PRECHARGE BANK BANK tDS tDH tDS DIN m DQ tDH DIN m + 2 tDS tDH DIN m + 3 tRCD DON’T CARE NOTE: 1. For this example, the burst length = 4. 2. A9 and A11 = “Don’t Care.” 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 53 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM 86-PIN PLASTIC TSOP (400 MIL) SEE DETAIL A 22.22 ±.08 .61 .50 TYP .10 (2X) +.07 0.20 -.03 2.80 (2X) 11.76 ±.10 10.16 ±.08 R .75 (2X) PIN #1 ID +.03 .15 -.02 R 1.00 (2X) .25 GUAGE PLANE +.10 .10 -.05 .10 .50 ±.10 1.20 MAX .80 TYP DETAIL A NOTE: 1. All dimensions in millimeters. 2. Package width and length do not include mold protrusion; allowable mold protrusion is 0.25mm per side. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 54 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc. PRELIMINARY 256Mb: x32 SDRAM 90-BALL FBGA (8mm x 13mm) 0.65 ±0.05 SEATING PLANE C 0.10 C SOLDER BALL MATERIAL: 62% Sn, 36% Pb, 2% Ag OR 96.5% Sn, 3%Ag, 0.5% Cu SOLDER MASK DEFINED BALL PADS: Ø0.40 90X Ø0.45 ±0.05 SOLDER BALL DIAMETER REFERS TO POST REFLOW CONDITION. THE PREREFLOW DIAMETER IS Ø0.42 SUBSTRATE MATERIAL: PLASTIC LAMINATE MOLD COMPOUND: EPOXY NOVOLAC 6.40 0.80 TYP BALL A1 ID BALL A1 ID BALL A1 BALL A9 0.80 TYP 11.20 ±0.10 CL 13.00 ±0.10 5.60 ±0.05 6.50 ±0.05 CL 3.20 ±0.05 1.00 MAX 4.00 ±0.05 8.00 ±0.10 (Bottom View) NOTE: 1. All dimensions in millimeters. 2. Recommended pad size for PCB is 0.33mm±0.025mm. Preliminary: This data sheet contains initial characterization limits that are subject to change upon full characterization of production devices. 8000 S. Federal Way, P.O. Box 6, Boise, ID 83707-0006, Tel: 208-368-3900 E-mail: [email protected], Internet: http://www.micronsemi.com, Customer Comment Line: 800-932-4992 Micron, the M logo, and the Micron logo are trademarks of Micron Technology, Inc. All other trademarks are the property of their respective owners. 09005aef80cd8e48 256MbSDRAMx32.p65 – Rev. B; Pub. 03/04 55 Micron Technology, Inc., reserves the right to change products or specifications without notice. ©2003 Micron Technology, Inc.