64Mx72 bits PC100 SDRAM Registered DIMM with PLL, based on 64Mx4 SDRAM with LVTTL, 4 banks & 8K Refresh HYM72V64C756T4P Series DESCRIPTION The HYM72V64C756T4P -Series are high speed 3.3-Volt synchronous dynamic RAM Modules composed of eighteen 64Mx4 bit Synchronous DRAMs in 54-pin TSOPII, two 48-pin SOP Register Buffers, one 24-pin SOP PLL and 8-pin TSSOP 2K bit EEPROM on a 168-pin glass-epoxy printed circuit board. One 0.22µF and one 0.0022µF decoupling capacitors per each SDRAM are mounted on the module. The HYM72V64C756T4P -Series are gold plated socket type Dual In-line Memory Modules suitable for easy interchange and addition of 512M bytes memory. All addresses, data and control inputs are latched on the rising edge of the master clock input. The data paths are internally pipelined to achieve very high bandwidths. FEATURES • • • • • • • • • • • • 1.700 (43.18mm) PCB Height 168-Pin Registered DIMM with Double Sided ECC support One 0.22µF and one 0.0022µF decoupling capacitors adopted Serial Presence Detect with Serial EEPROM Two Register Buffers & one Inverter used (with PLL) Supports Flow-through or Register mode by Pin No. 147 (REGE) Meets all the other JEDEC specifications Single 3.3V±0.3V power supply All device pins are LVTTL compatible 8192 refresh cycles every 64ms Auto precharge/precharge all banks by A 10 flag • Possible to assert random column address every clock cycle • Interleaved auto refresh mode Programmable burst lengths and sequences - 1,2,4,8,full page for Sequential type - 1,2,4,8 for Interleave type • Programmable /CAS latency ; 2,3 clocks • Support clock suspend/power down mode by CKE0 • Data mask function by DQM • Mode register set programming • Burst termination command • Self refresh provides minimum power, full internal refresh control ORDERING INFORMATION Part No. Clock Frequency HYM72V64C756T4P-8 125MHz HYM72V64C756T4P-P 100MHz HYM72V64C756T4P-S 100MHz Internal Bank Ref. Power SDRAM Package Plating 4 Banks 8K Normal TSOP-II Gold This document is a general product description and is subject to change without notice. Hyundai Electronics does not assume any responsibility for use of circuits described. No patent licenses are implied. Rev. 1.0/Jul.00 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series PIN DESCRIPTION PIN PIN NAME DESCRIPTION CK0~CK3 Clock Inputs The system clock input. All other inputs are registered to the SDRAM on the rising edge of CLK CKE0 Clock Enable Controls internal clock signal and when deactivated, the SDRAM will be one of the states among power down, suspend or self refresh /S0, /S2 Chip Select Enables or disables all inputs except CK, CKE and DQM BA0, BA1 SDRAM Bank Address Selects bank to be activated during /RAS activity Selects bank to be read/written during /CAS activity A0 ~ A12 Address Row Address : RA0 ~ RA12, Column Address : CA0 ~ CA9, CA11 Auto-precharge flag : A10 /RAS, /CAS, /WE Row Address Strobe, Column Address Strobe, Write Enable /RAS, /CAS and /WE define the operation Refer function truth table for details REGE Register Enable Register Enable pin which permits the DIMM to operateion in Buffered Mode when REGE input is Low, in Registered Mode when REGE input is High DQM0~DQM7 Data Input/Output Mask Controls output buffers in read mode and masks input data in write mode DQ0 ~ DQ63 Data Input/Output Multiplexed data input / output pin CB0 ~ CB7 Check Bit Input/Output Check bits for ECC VCC Power Supply (3.3V) Power supply for internal circuits and input buffers VSS Ground Ground SCL SPD Clock Input Serial Presence Detect Clock input SDA SPD Data Input/Output Serial Presence Detect Data input/output SA0~2 SPD Address Input Serial Presence Detect Address Input WP Write Protect for SPD Write Protect for Serial Presence Detect on DIMM NC No Connection No connection Rev. 1.0/Jul.00 2 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series PIN ASSIGNMENTS FRONT SIDE BACK SIDE PIN NO. NAME PIN NO. 1 VSS 2 DQ0 3 FRONT SIDE BACK SIDE NAME PIN NO. NAME PIN NO. NAME 85 VSS 41 VCC 125 *CK1 86 DQ32 42 CK0 126 A12 DQ1 87 DQ33 43 VSS 127 VSS 4 DQ2 88 DQ34 44 NC 128 CKE0 5 DQ3 89 DQ35 45 /S2 129 NC 6 VCC 90 VCC 46 DQM2 130 DQM6 7 DQ4 91 DQ36 47 DQM3 131 DQM7 8 DQ5 92 DQ37 48 NC 132 NC 9 DQ6 93 DQ38 49 VCC 133 VCC 10 DQ7 94 DQ39 Architecture Key 50 NC 134 NC 51 NC 135 NC CB6 52 CB2 136 11 DQ8 95 DQ40 53 CB3 137 CB7 12 VSS 96 VSS 54 VSS 138 VSS 13 DQ9 97 DQ41 55 DQ16 139 DQ48 14 DQ10 98 DQ42 56 DQ17 140 DQ49 15 DQ11 99 DQ43 57 DQ18 141 DQ50 16 DQ12 100 DQ44 58 DQ19 142 DQ51 17 DQ13 101 DQ45 59 VCC 143 VCC 18 VCC 102 VCC 60 DQ20 144 DQ52 19 DQ14 103 DQ46 61 NC 145 NC 20 DQ15 104 DQ47 62 NC 146 NC 21 CB0 105 CB4 63 NC 147 REGE 22 CB1 106 CB5 64 VSS 148 VSS 23 VSS 107 VSS 65 DQ21 149 DQ53 24 NC 108 NC 66 DQ22 150 DQ54 25 NC 109 NC 67 DQ23 151 DQ55 26 VCC 110 VCC 68 VCC 152 VCC 27 /WE 111 /CAS 69 DQ24 153 DQ56 28 DQM0 112 DQM4 70 DQ25 154 DQ57 29 DQM1 113 DQM5 71 DQ26 155 DQ58 30 /S0 114 NC 72 DQ27 156 DQ59 31 NC 115 /RAS 73 VCC 157 VCC 32 VSS 116 VSS 74 DQ28 158 DQ60 33 A0 117 A1 75 DQ29 159 DQ61 34 A2 118 A3 76 DQ30 160 DQ62 35 A4 119 A5 77 DQ31 161 DQ63 36 A6 120 A7 78 VSS 162 VSS 37 A8 121 A9 79 CK2 163 *CK3 38 A10/AP 122 BA0 80 NC 164 NC 39 BA1 123 A11 81 WP 165 SA0 40 VCC 124 VCC 82 SDA 166 SA1 83 SCL 167 SA2 84 VCC 168 VCC Voltage Key Note : * CK1 ~ CK3 are connected with termination R/C (Refer to the block diagram) Rev. 1.0/Jul.00 3 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series BLOCK DIAGRAM Note : 1. The serial resistor values of DQs are 10ohms 2. The padding capacitance of termination R/C for CK1~CK3 is 12pF Rev. 1.0/Jul.00 4 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series SERIAL PRESENCE DETECT BYTE NUMBER FUNCTION DESCRIPTION FUNCTION -8 VALUE -P -S -8 -P BYTE0 # of Bytes Written into Serial Memory at Module Manufacturer 128 Bytes 80h BYTE1 Total # of Bytes of SPD Memory Device 256 Bytes 08h BYTE2 Fundamental Memory Type BYTE3 -S SDRAM 04h # of Row Addresses on This Assembly 13 0Dh BYTE4 # of Column Addresses on This Assembly 11 0Bh BYTE5 # of Module Banks on This Assembly 1 Bank 01h BYTE6 Data Width of This Assembly 72 Bits 48h BYTE7 Data Width of This Assembly (Continued) - 00h BYTE8 Voltage Interface Standard of This Assembly LVTTL 01h BYTE9 SDRAM Cycle Time @/CAS Latency=3 8ns 10ns 10ns 80h A0h A0h BYTE10 Access Time from Clock @/CAS Latency=3 6ns 6ns 6ns 60h 60h 60h BYTE11 DIMM Configuration Type BYTE12 Refresh Rate/Type BYTE13 BYTE14 BYTE15 Minimum Clock Delay Back to Back Random Column Address BYTE16 Burst Lenth Supported BYTE17 # of Banks on Each SDRAM Device BYTE18 SDRAM Device Attributes, /CAS Lataency BYTE19 SDRAM Device Attributes, /CS Lataency BYTE20 SDRAM Device Attributes, /WE Lataency BYTE21 SDRAM Module Attributes BYTE22 SDRAM Device Attributes, General BYTE23 ECC 02h 7.8125us / Self Refresh Supported 82h Primary SDRAM Width x4 04h Error Checking SDRAM Width x4 04h BYTE25 BYTE26 BYTE29 01h 12ns 6ns - 20ns 48ns A0h 60h 00h 20ns 20ns Data Signal Input Setup Time Superset Information (may be used in future) 2ns Manufacturer JEDEC ID Code BYTE65 ~71 Manufacturing Location 00h 14h 14h 14h 30h 14h 32h 80h 2ns 1ns C0h 60h 00h 20ns 1ns 20h 10h 2ns 1ns 20h 10h 20h 10h 20h 10h - SPD Revision Checksum for Byte 0~62 2 00h 14h 10h 50ns 2ns 1ns Data Signal Input Hold Time Rev. 1.0/Jul.00 /WE Latency=0 512MB Command and Address Signal Input Setup Time BYTE62 01h - Minimum /RAS to /CAS Delay (tRCD) BYTE33 BYTE36 06h /CS Latency=0 20ns BYTE31 BYTE34 /CAS Latency=2,3 10ns 16ns Minimum /RAS Pulse Width (tRAS) 04h 6ns Access Time from Clock @/CAS Latency=1 BYTE28 4 Banks Single Bit Write, Precharge All, Auto Precharge, Early RAS Precharge - Minimum Row Precharge Time (tRP) 01h 8Fh 1 Registered inputs, with PLL SDRAM Cycle Time @/CAS Latency=2 Access Time from Clock @/CAS Latency=2 tCCD = 1 CLK 1,2,4,8,Full Page NOTE 12h - A3h 3, 8 C3h Hynix JEDED ID Unused FFh Hynix (Korea Area) 0*h 1*h HSE (Europe Area) HSJ (Japan Area) 3*h 4*h 5 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series Continued BYTE NUMBER FUNCTION DESCRIPTION BYTE73 Manufacturer’s Part Number (Component) BYTE74 Manufacturer’s Part Number (256Mb based) BYTE75 Manufacturer’s Part Number (Voltage Interface) BYTE76 BYTE77 FUNCTION -8 -P VALUE -S -8 -P NOTE -S 7 (SDRAM) 37h 4, 5 2 32h 4, 5 V (3.3V, LVTTL) 56h 4, 5 Manufacturer’s Part Number (Memory Width) 6 36h 4, 5 ....Manufacturer’s Part Number (Memory Width) 4 34h 4, 5 BYTE78 Manufacturer’s Part Number (Module Type) C 43h 4, 5 BYTE79 Manufacturer’s Part Number (Data Width) 7 37h 4, 5 BYTE80 ....Manufacturer’s Part Number (Data Width) 5 35h 4, 5 BYTE81 Manufacturer’s Part Number (Refresh, SDRAM Bank) 6 (8K Refresh, 4Banks) 36h 4, 5 BYTE82 Manufacturer’s Part Number (Generation) T 54h 4, 5 BYTE83 Manufacturer’s Part Number (Package Type) 4 (x4 based) 34h 4, 5 BYTE84 Manufacturer’s Part Number (Itanium Server) P 50h 4, 5 BYTE85 Manufacturer’s Part Number (Hyphent) BYTE86 Manufacturer’s Part Number (Min. Cycle Time) BYTE87 ~90 Manufacturer’s Part Number BYTE91 - (Hyphen) 8 P 2Dh S 38h 50h 4, 5 53h 4, 5 Blanks 20h 4, 5 Revision Code (for Component) Process Code - 4, 6 BYTE92 ....Revision Code (for PCB) Process Code - 4, 6 BYTE93 Manufacturing Date Work Week - 3, 6 BYTE94 ....Manufacturing Date Year - 3, 6 Serial Number - 6 None 00h BYTE95 ~98 BYTE99 ~125 Assembly Serial Number Manufacturer Specific Data (may be used in future) BYTE126 System Frequency Support BYTE127 Intel Specification Details for 100MHz Support BYTE128 ~256 Unused Storage Locations 100MHz Refer to Note7 - 64h 8Fh 7, 8 8Dh 7, 8 00h Note : 1. The bank address is excluded 2. 1, 2, 4, 8 for Interleave Burst Type 3. BCD adopted 4. ASCII adopted 5. Basically Hynix writes Part No. except for H ‘ YM’in Byte 73~90 to use the limited 18 bytes from byte 73 to byte 90 6. Not fixed but dependent 7. CK0 connected to DIMM, TBD junction temp, CL2(3) support, Intel defined Concurrent Auto Precharge support 8. Refer to Intel SPD Specification 1.2B 9. Refer to Hynix Web site . Rev. 1.0/Jul.00 6 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series ABSOLUTE MAXIMUM RATINGS Parameter Symbol Rating Unit Ambient Temperature TA 0 ~ 70 °C Storage Temperature TSTG -55 ~ 125 °C Voltage on Any Pin relative to V SS VIN, VOUT -1.0 ~ 4.6 V Voltage on VDD relative to VSS VDD, VDDQ -1.0 ~ 4.6 V Short Circuit Output Current IOS 50 mA Power Dissipation PD 1 W Soldering Temperature ⋅ Time TSOLDER 260 ⋅ 10 °C ⋅ Sec Note : Operation at above absolute maximum rating can adversely affect device reliability. DC OPERATING CONDITION (TA=0 to 70°C) Parameter Symbol Min Typ Max Unit Note Power Supply Voltage VDD, VDDQ 3.0 3.3 3.6 V 1 Input High voltage VIH 2.0 3.0 VDDQ + 0.3 V 1,2 Input Low voltage VIL -0.3 0 0.8 V 1,3 Note Note : 1.All voltages are referenced to VSS = 0V 2.VIH(max) is acceptable 5.6V AC pulse width with <=3ns of duration. 3.VIL(min) is acceptable -2.0V AC pulse width with <=3ns of duration. AC OPERATING TEST CONDITION (TA=0 to 70°C, VDD=3.3±0.3V, VSS=0V) Parameter Symbol Value Unit AC Input High / Low Level Voltage VIH / VIL 2.4/0.4 V Vtrip 1.4 V Input Rise / Fall Time tR / tF 1 ns Output Timing Measurement Reference Level Voltage Voutref 1.4 V CL 50 pF Input Timing Measurement Reference Level Voltage Output Load Capacitance for Access Time Measurement 1 Note : 1.Output load to measure access times is equivalent to two TTL gates and one capacitor (50pF). For details, refer to AC/DC output load circuit Rev. 1.0/Jul.00 7 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series CAPACITANCE (TA=25°C, f=1MHz) -8/P/S Parameter Pin Input Capacitance Data Input / Output Capacitance Symbol Unit Min Max CK0 CI1 - 40 pF CKE0 CI2 - 16 pF /S0, /S2 CI3 - 16 pF A0~11, BA0, BA1 CI4 - 16 pF /RAS, /CAS, /WE CI5 - 16 pF DQM0~DQM7 CI 6 - 16 pF DQ0 ~ DQ63 CI/O - 17 pF OUTPUT LOAD CIRCUIT Vtt=1.4V RT=250 Ω Output Output 50pF DC Output Load Circuit Rev. 1.0/Jul.00 50pF AC Output Load Circuit 8 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series DC CHARACTERISTICS I (TA=0 to 70°C, VDD=3.3±0.3V) Parameter Symbol Min. Max Unit Note Input Leakage Current ILI -2 2 uA 1 Output Leakage Current ILO -1 1 uA 2 Output High Voltage VOH 2.4 - V IOH = -4mA Output Low Voltage VOL - 0.4 V IOL = +4mA Note : 1.VIN = 0 to 3.6V, All other pins are not tested under V IN =0V 2.DOUT is disabled, VOUT=0 to 3.6 DC CHARACTERISTICS II Speed Parameter Operating Current Symbol IDD1 Test Condition Burst length=1, One bank active tRC ≥ tRC(min), IOL=0mA -8 -P -S 2600 2600 2600 CKE ≤ VIL(max), tCK = 15ns 356 CKE ≤ VIL(max), tCK = ∞ 356 CKE ≥ VIH(min), CS ≥ VIH(min), tCK = 15ns Input signals are changed one time during 30ns. All other pins ≥ VDD-0.2V or ≤ 0.2V 760 IDD2NS CKE ≥ VIH(min), tCK = ∞ Input signals are stable. 270 IDD3P CKE ≤ VIL(max), tCK = 15ns 192 IDD3PS CKE ≤ VIL(max), tCK = ∞ 93 IDD3N CKE ≥ VIH(min), CS ≥ VIH(min), tCK = 15ns Input signals are changed one time during 30ns. All other pins ≥ VDD-0.2V or ≤ 0.2V 700 IDD3NS CKE ≥ VIH(min), tCK = ∞ Input signals are stable. 300 Burst Mode Operating Current IDD4 tCK ≥ tCK(min), IOL=0mA All banks active Auto Refresh Current IDD5 tRRC ≥ tRRC(min), All banks active Self Refresh Current IDD6 CKE ≤ 0.2V IDD2P Precharge Standby Current in Power Down Mode IDD2PS IDD2N Precharge Standby Current in Non Power Down Mode Active Standby Current in Power Down Mode Active Standby Current in Non Power Down Mode Unit Note mA 1 mA mA mA mA CL=3 3120 3120 3120 CL=2 3120 3120 3120 mA 1 6240 mA 2 108 mA Note : 1. IDD1 and IDD4 depend on output loading and cycle rates. Specified values are measured with the output open 2. Min. of tRRC (Refresh RAS cycle time) is shown at AC CHARACTERISTICS II Rev. 1.0/Jul.00 9 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series AC CHARACTERISTICS I (AC operating conditions unless otherwise noted) -8 Parameter Min System Clock Cycle Time CAS Latency = 3 -P tCK3 Max 8 Min Max 10 1000 Min Unit Note 1000 ns 1 Max 10 1000 tCK2 10 Clock High Pulse Width tCHW 3 - 3 - 3 - ns 2 Clock Low Pulse Width tCLW 3 - 3 - 3 - ns 2 CAS Latency = 3 tAC3 - 6 - 6 - 6 ns CAS Latency = 2 tAC2 - 6 - 6 - 6 ns Data-Out Hold Time tOH 3 - 3 - 3 - ns Data-Input Setup Time tDS 2 - 2 - 2 - ns 2 Data-Input Hold Time tDH 1 - 1 - 1 - ns 2 Address Setup Time tAS 2 - 2 - 2 - ns 2 Address Hold Time tAH 1 - 1 - 1 - ns 2 CKE Setup Time tCKS 2 - 2 - 2 - ns 2 CKE Hold Time tCKH 1 - 1 - 1 - ns 2 Command Setup Time tCS 2 - 2 - 2 - ns 2 Command Hold Time tCH 1 - 1 - 1 - ns 2 CLK to Data Output in Low-Z Time tOLZ 1 - 1 - 1 - ns CAS Latency = 3 tOHZ3 3 6 3 6 3 6 ns CAS Latency = 2 tOHZ2 3 6 3 6 3 6 ns Access Time From Clock CLK to Data Output in High-Z Time CAS Latency = 2 -S Symbol 10 12 3 Note : 1. In Registered DIMM, data is delayed an additional clock cycle due to the register (this is, Device CL + 1 = DIMM CL) 2.Assume tR / tF (input rise and fall time ) is 1ns, If tR & tF > 1ns, then [(tR+tF)/2-1]ns should be added to the parameter 3.Access times to be measured with input signals of 1v/ns edge rate, from 0.8v to 2.0v If tR > 1ns, then (tR/2-0.5)ns should be added to the parameter Rev. 1.0/Jul.00 10 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series AC CHARACTERISTICS II -8 Parameter -P -S Symbol Unit Min Max Min Max Min Max Note Operation tRC 68 - 70 - 70 - ns Auto Refresh tRRC 68 - 70 - 70 - ns RAS to CAS Delay tRCD 20 - 20 - 20 - ns RAS Active Time tRAS 48 100K 50 100K 50 100K ns RAS Precharge Time tRP 20 - 20 - 20 - ns RAS to RAS Bank Active Delay tRRD 16 - 20 - 20 - ns CAS to CAS Delay tCCD 1 - 1 - 1 - CLK Write Command to Data-In Delay tWTL 0 - 0 - 0 - CLK 1 Data-In to Precharge Command tDPL 2 - 2 - 2 - CLK 1 Data-In to Active Command tDAL 5 - 5 - 4 - CLK 1 DQM to Data-Out Hi-Z tDQZ 3 - 3 - 3 - CLK 1 DQM to Data-In Mask tDQM 0 - 0 - 0 - CLK MRS to New Command tMRD 2 - 2 - 2 - CLK CAS Latency = 3 tPROZ3 4 - 4 - 4 - CAS Latency = 2 tPROZ2 3 - 3 - 3 - Power Down Exit Time tPDE 1 - 1 - 1 - CLK Self Refresh Exit Time tSRE 1 - 1 - 1 - CLK Refresh Time tREF - 64 - 64 - 64 ms RAS Cycle Time Precharge to Data Output Hi-Z CLK 1 2 Note : 1. Timing delay due to the register is considered in a registered DIMM 2. A new command can be given tRRC after self refresh exit Rev. 1.0/Jul.00 11 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series DEVICE OPERATING OPTION TABLE HYM72V64C756T4P-8 CAS Latency tRCD tRAS tRC tRP tAC tOH 125MHz(8ns) 3CLKs 3CLKs 6CLKs 9CLKs 3CLKs 6ns 3ns 100MHz(10ns) 2CLKs 2CLKs 5CLKs 7CLKs 2CLKs 6ns 3ns 83MHz(12ns) 2CLKs 2CLKs 4CLKs 6CLKs 2CLKs 6ns 3ns HYM72V64C756T4P-P CAS Latency tRCD tRAS tRC tRP tAC tOH 100MHz(10ns) 2CLKs 2CLKs 5CLKs 7CLKs 2CLKs 6ns 3ns 83MHz(12ns) 2CLKs 2CLKs 5CLKs 7CLKs 2CLKs 6ns 3ns 66MHz(15ns) 2CLKs 2CLKs 4CLKs 6CLKs 2CLKs 6ns 3ns HYM72V64C756T4P-S CAS Latency tRCD tRAS tRC tRP tAC tOH 100MHz(10ns) 3CLKs 2CLKs 5CLKs 7CLKs 2CLKs 6ns 3ns 83MHz(12ns) 2CLKs 2CLKs 5CLKs 7CLKs 2CLKs 6ns 3ns 66MHz(15ns) 2CLKs 2CLKs 4CLKs 6CLKs 2CLKs 6ns 3ns Note : DIMM/CAS Latency = Device CL + 1 (Registered Mode) Rev. 1.0/Jul.00 12 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series COMMAND TRUTH TABLE Command Mode Register Set No Operation CKEn-1 CKEn H X H Bank Active H CS RAS CAS DQM X OP code X X L L L L H X X X L H H H L L H H X X A10/ AP WE ADDR X RA Read Note V L H X L H L H X CA Read with Autoprecharge V H Write L H X L H L L X CA Write with Autoprecharge V H Precharge All Banks H X L V H X L L H L X Burst Stop H X L H H L X X DQM H V X Auto Refresh H Precharge selected Bank Burst-Read-SingleWRITE Self Refresh BA X H L L H X X A9 Pin High (Other Pins OP code) H X L L L H X Entry H L L L L H X H X X X Exit L H 1 Entry H X X L H H H H X X X L H H H H X X X L H H H H X X X L V V V L Precharge power down X X Exit Clock Suspend L X Entry Exit L H L H X L H X X X X Note : 1. Exiting Self Refresh occurs by asynchronously bringing CKE from low to high 2. X = Don′t care, H = Logic High, L = Logic Low. BA =Bank Address, RA = Row Address, CA = Column Address, Opcode = Operand Code, NOP = No Operation Rev. 1.0/Jul.00 13 PC100 SDRAM Registered DIMM HYM72V64C756T4P Series PACKAGE DEMENSION Rev. 1.0/Jul.00 14