ADE-203-269A (Z) HM514400B/BL Series HM514400C/CL Series 1,048,576-word × 4-bit Dynamic Random Access Memory Rev. 1.0 Nov. 29, 1994 The Hitachi HM514400B/BL, HM514400C/CL are CMOS dynamic RAM organized 1,048,576word × 4-bit. HM514400B/BL, HM514400C/CL have realized higher density, higher performance and various functions by employing 0.8 µm CMOS process technology and some new CMOS circuit design technologies. The HM514400B/BL, HM514400C/CL offer Fast Page Mode as a high speed access mode. Multiplexed address input permits the HM514400B/BL, HM514400C/CL to be packaged in standard 300-mil 26-pin plastic SOJ, standard 400-mil 20-pin plastic ZIP and 26pin plastic TSOP II. Features • Single 5 V (±10%) • High speed — Access time 60 ns/70 ns/80 ns (max) • Low power dissipation — Active mode 605 mW/550 mW/495 mW (max) — Standby mode 11 mW (max) 0.55 mW (max) (L-version) • Fast page mode capability • 1024 refresh cycles : 16 ms 1024 refresh cycles : 128 ms (L-version) • 3 variations of refresh — RAS-only refresh — CAS-before-RAS refresh — Hidden refresh • Test function • Battery back up operation — HM514400BL Series (L-version) — HM514400CL Series (L-version) HM514400B/BL, HM514400C/CL Series Ordering Information Type No. Access time Package Type No. Access time Package HM514400BS-6 HM514400BS-7 HM514400BS-8 60 ns 70 ns 80 ns 300-mil 26-pin plastic SOJ (CP-26/20D) HM514400CZ-6 HM514400CZ-7 HM514400CZ-8 60 ns 70 ns 80 ns 400-mil 20-pin plastic ZIP (ZP-20) HM514400BLS-6 HM514400BLS-7 HM514400BLS-8 60 ns 70 ns 80 ns HM514400CLZ-6 HM514400CLZ-7 HM514400CLZ-8 60 ns 70 ns 80 ns HM514400CS-6 HM514400CS-7 HM514400CS-8 60 ns 70 ns 80 ns HM514400BTT-6 HM514400BTT-7 HM514400BTT-8 60 ns 70 ns 80 ns HM514400CLS-6 HM514400CLS-7 HM514400CLS-8 60 ns 70 ns 80 ns HM514400BLTT-6 HM514400BLTT-7 HM514400BLTT-8 60 ns 70 ns 80 ns HM514400BZ-6 HM514400BZ-7 HM514400BZ-8 60 ns 70 ns 80 ns HM514400CTT-6 HM514400CTT-7 HM514400CTT-8 60 ns 70 ns 80 ns HM514400BLZ-6 HM514400BLZ-7 HM514400BLZ-8 60 ns 70 ns 80 ns HM514400CLTT-6 HM514400CLTT-7 HM514400CLTT-8 60 ns 70 ns 80 ns 2 400-mil 20-pin plastic ZIP (ZP-20) 26-pin plastic TSOPII (TTP-26/20D) HM514400B/BL, HM514400C/CL Series Pin Arrangement HM514400BS/BLS Series HM514400CS/CLS Series HM514400BZ/BLZ Series HM514400CZ/CLZ Series 1 OE I/O1 1 26 VSS CAS 2 I/O2 2 25 I/O4 I/O4 4 WE 3 24 I/O3 RAS 4 23 CAS 3 I/O3 5 VSS I/O1 6 7 I/O2 WE 8 A9 5 22 OE 9 RAS A9 10 11 A0 A0 9 18 A8 A1 12 13 A2 A1 10 17 A7 A3 14 A2 11 16 A6 A4 16 A3 12 15 A5 A6 18 VCC 13 14 A4 A8 20 15 VCC 17 A5 (Top view) 19 A7 (Bottom view) HM514400BTT/BLTT Series HM514400CTT/CLTT Series I/O1 1 26 VSS I/O2 2 25 I/O4 WE 3 24 I/O3 RAS 4 23 CAS A9 5 22 OE A0 9 18 A8 A1 10 17 A7 A2 11 16 A6 A3 12 15 A5 VCC 13 14 A4 (Top view) 3 HM514400B/BL, HM514400C/CL Series Pin Description Pin name Function A0 to A9 Address input A0 to A9 Refresh address input I/O1 to I/O4 Data-in/Data-out RAS Row address strobe CAS Column address strobe WE Read/Write enable OE Output enable VCC Power (+5 V) VSS Ground 4 Row Driver Row Driver 256 k Memory Array Mat Row Driver Row Driver Row Address Buffer CAS Control Circuit WE Control Circuit OE Control Circuit Row Driver Row Driver Row Driver Row Driver 256 k Memory Array Mat OE 256 k Memory Array Mat WE I/O Bus & Column Decoder 256 k Memory Array Mat Row Driver 256 k Memory Array Mat CAS I/O Bus & Column Decoder 256 k Memory Array Mat Row Decoder & Peripheral Circuit Row Driver 256 k Memory Array Mat I/O Bus & Column Decoder 256 k Memory Array Mat Row Driver I/O Bus & Column Decoder Row Driver 256 k Memory Array Mat Row Driver 256 k Memory Array Mat Row Driver I/O Bus & Column Decoder 256 k Memory Array Mat RAS I/O Bus & Column Decoder Row Driver 256 k Memory Array Mat Row Driver 256 k Memory Array Mat I/O Bus & Column Decoder 256 k Memory Array Mat RAS Control Circuit 256 k Memory Array Mat I/O Bus & Column Decoder 256 k Memory Array Mat HM514400B/BL, HM514400C/CL Series Block Diagram I/O1 I/O2 I/O3 I/O4 I/O1 Buffer I/O2 Buffer I/O3 Buffer I/O4 Buffer Column Address Buffer Address A0–A9 5 HM514400B/BL, HM514400C/CL Series Absolute Maximum Ratings Parameter Symbol Value Unit Voltage on any pin relative to VSS VT –1.0 to +7.0 V Supply voltage relative to VSS VCC –1.0 to +7.0 V Short circuit output current Iout 50 mA Power dissipation PT 1.0 W Operating temperature Topr 0 to +70 °C Storage temperature Tstg –55 to +125 °C Recommended DC Operating Conditions (Ta = 0 to +70°C) Parameter Symbol Min Typ Max Unit Supply voltage VSS 0 0 0 V VCC 4.5 5.0 5.5 V 1 Input high voltage VIH 2.4 — 6.5 V 1 Input low voltage VIL –1.0 — 0.8 V 1 Note: 6 1. All voltage referred to VSS. Note HM514400B/BL, HM514400C/CL Series DC Characteristics (Ta = 0 to +70°C, VCC = 5 V ± 10%, VSS = 0 V) HM514400B/BL, HM514400C/CL -6 -7 -8 Parameter Symbol Min Max Min Max Min Max Unit Test conditions Operating current ICC1 — 110 — 100 — 90 mA RAS, CAS cycling tRC = min Standby current ICC2 — 2 — 2 — 2 mA TTL interface RAS, CAS = VIH Dout = High-Z — 1 — 1 — 1 mA CMOS interface RAS, CAS ≥ VCC – 0.2 V Dout = High-Z Notes 1, 2 Standby current (L-version) ICC2 — 100 — 100 — 100 µA CMOS interface 4 RAS, CAS =VIH WE, OE, Address and Din = VIH or VIL Dout = High-Z RAS-only refresh current ICC3 — 110 — 100 — 90 mA tRC = min Standby current ICC5 — 5 5 5 mA RAS = VIH, CAS = VIL 1 Dout = enable CAS-before-RAS refresh current ICC6 — 110 — 100 — 90 mA tRC = min Fast page mode current ICC7 — 110 — 100 — 90 mA tPC = min 1, 3 Battery back up current (Standby with CBR refresh) (L-version) ICC10 — 200 — 200 — 200 µA tRC = 125 µs tRAS ≤ 1 µs WE = VIH, CAS = VIL OE, Address and Din = VIH or VIL Dout = High-Z 4 Input leakage current ILI –10 10 –10 10 –10 10 µA 0 V ≤ Vin ≤ 7 V Output leakage current ILO –10 10 –10 10 –10 10 µA 0 V ≤ Vout ≤ 7 V Dout = disable Output high voltage VOH 2.4 VCC 2.4 VCC 2.4 VCC V High Iout = –5 mA Output low voltage VOL 0 0.4 0.4 0.4 Low Iout = 4.2 mA — 0 — 0 V 2 Notes: 1. ICC depends on output load condition when the device is selected. ICC max is specified at the output open condition. 2. Address can be changed twice or less while RAS = VIL. 3. Address can be changed once or less while CAS = VIH. 4. VCC – 0.2 V ≤ VIH ≤ 6.5 V and 0 V ≤ VIL ≤ 0.2 V. 7 HM514400B/BL, HM514400C/CL Series Capacitance (Ta = 25°C, VCC = 5 V ± 10%) Parameter Symbol Typ Max Unit Notes Input capacitance (Address) CI1 — 5 pF 1 Input capacitance (Clocks) CI2 — 7 pF 1 Output capacitance (Data-in, Data-out) CI/O — 7 pF 1, 2 Notes: 1. Capacitance measured with Boonton Meter or effective capacitance measuring method. 2. CAS = VIH to disable Dout. AC Characteristics (Ta = 0 to +70°C, VCC = 5 V ± 10%, VSS = 0 V) *1, *14, *15, *16 Test Conditions • Input rise and fall times : 5 ns • Input timing reference levels : 0.8 V, 2.4 V • Output load : 2 TTL gate + CL (100 pF) (Including scope and jig) 8 HM514400B/BL, HM514400C/CL Series Read, Write, Read-Modify-Write and Refresh Cycles (Common parameters) HM514400B/BL, HM514400C/CL -6 -7 -8 Parameter Symbol Min Max Min Max Min Max Unit Notes Random read or write cycle time tRC 110 — 130 — 150 — ns RAS precharge time tRP 40 — 50 — 60 — ns RAS pulse width tRAS 60 10000 70 10000 80 10000 ns 19 CAS pulse width tCAS 15 10000 20 10000 20 10000 ns 20 Row address setup time tASR 0 — 0 — 0 — ns Row address hold time tRAH 10 — 10 — 10 — ns Column address setup time tASC 0 — 0 — 0 — ns Column address hold time tCAH 15 — 15 — 15 — ns RAS to CAS delay time tRCD 20 45 20 50 20 60 ns 8 RAS to column address delay time tRAD 15 30 15 35 15 40 ns 9 RAS hold time tRSH 15 — 20 — 20 — ns CAS hold time tCSH 60 — 70 — 80 — ns CAS to RAS precharge time tCRP 10 — 10 — 10 — ns OE to Din delay time tODD 15 — 20 — 20 — ns OE delay time from Din tDZO 0 — 0 — 0 — ns CAS setup time from Din tDZC 0 — 0 — 0 — ns Transition time (rise and fall) tT 3 50 3 50 3 50 ns Refresh period tREF — 16 — 16 — 16 ms Refresh period (L-version) tREF — 128 — 128 — 128 ms 7 9 HM514400B/BL, HM514400C/CL Series Read Cycle HM514400B/BL, HM514400C/CL -6 -7 -8 Parameter Symbol Min Max Min Max Min Max Unit Notes Access time from RAS tRAC — 60 — 70 — 80 ns 2, 3, 17 Access time from CAS tCAC — 15 — 20 — 20 ns 3, 4, 13, 17 Access time from address tAA — 30 — 35 — 40 ns 3, 5, 13, 17 Access time from OE tOAC — 15 — 20 — 20 ns 3, 17 Read command setup time tRCS 0 — 0 — 0 — ns Read command hold time to CAS tRCH 0 — 0 — 0 — ns 18 Read command hold time to RAS tRRH 0 — 0 — 0 — ns 18 Column address to RAS lead time tRAL 30 — 35 — 40 — ns Output buffer turn-off time tOFF1 0 15 0 20 0 20 ns 6 Output buffer turn-off time to OE tOFF2 0 15 0 20 0 20 ns 6 CAS to Din delay time tCDD 15 — 20 — 20 — ns OE pulse width tOEP 15 — 20 — 20 — ns Write Cycle HM514400B/BL, HM514400C/CL -6 -7 -8 Parameter Symbol Min Max Min Max Min Max Unit Notes Write command setup time tWCS 0 — 0 — 0 — ns 10 Write command hold time tWCH 15 — 15 — 15 — ns Write command pulse width tWP 10 — 10 — 10 — ns Write command to RAS lead time tRWL 15 — 20 — 20 — ns Write command to CAS lead time tCWL 15 — 20 — 20 — ns Data-in setup time tDS 0 — 0 — 0 — ns 11 Data-in hold time tDH 15 — 15 — 15 — ns 11 10 HM514400B/BL, HM514400C/CL Series Read-Modify-Write Cycle HM514400B/BL, HM514400C/CL -6 -7 -8 Parameter Symbol Min Max Min Max Min Max Unit Notes Read-modify-write cycle time tRWC 150 — 180 — 200 — ns RAS to WE delay time tRWD 80 — 95 — 105 — ns 10 CAS to WE delay time tCWD 35 — 45 — 45 — ns 10 Column address to WE delay time tAWD 50 — 60 — 65 — ns 10 OE hold time from WE tOEH 15 — 20 — 20 — ns Refresh Cycle HM514400B/BL, HM514400C/CL -6 -7 -8 Parameter Symbol Min Max Min Max Min Max Unit CAS setup time (CBR refresh cycle) tCSR 10 — 10 — 10 — ns CAS hold time (CBR refresh cycle) tCHR 10 — 10 — 10 — ns RAS precharge to CAS hold time tRPC 10 — 10 — 10 — ns CAS precharge time in normal mode tCPN 10 — 10 — 10 — ns Notes Fast Page Mode Cycle HM514400B/BL, HM514400C/CL -6 -7 -8 Parameter Symbol Min Max Min Max Min Max Unit Notes Fast page mode cycle time tPC 40 — 45 — 50 — ns Fast page mode CAS precharge time tCP 10 — 10 — 10 — ns Fast page mode RAS pulse width tRASC — 100000 — 100000 — 100000 ns 12 Access time from CAS precharge tACP — 35 — 40 — 45 ns 3, 13, 17 RAS hold time from CAS precharge tRHCP 35 — 40 — 45 — ns 11 HM514400B/BL, HM514400C/CL Series Fast Page Mode Read-Modify-Write Cycle HM514400B/BL, HM514400C/CL -6 -7 -8 Parameter Symbol Min Max Min Max Min Max Unit Notes Fast page mode read-modify-write cycle time tPCM 80 — 95 — 100 — ns Fast page mode read-modify-write cycle CAS precharge to WE delay time tCPW 55 — 65 — 70 — ns 10 Notes Test Mode Cycle HM514400B/BL, HM514400C/CL -6 -7 -8 Parameter Symbol Min Max Min Max Min Max Unit Test mode WE setup time tWS 0 — 0 — 0 — ns Test mode WE hold time tWH 10 — 10 — 10 — ns Counter Test Cycle HM514400B/BL, HM514400C/CL -6 -7 -8 Parameter Symbol Min Max Min Max Min Max Unit CAS precharge time in counter test cycle tCPT 40 — 40 — 40 — ns 12 Notes HM514400B/BL, HM514400C/CL Series Notes: 1. AC measurements assume tT = 5 ns. 2. Assumes that tRCD ≤ tRCD (max) and tRAD ≤ tRAD (max). If tRCD or tRAD is greater than the maximum recommended value shown in this table, tRAC exceeds the value shown. 3. Measured with a load circuit equivalent to 2 TTL loads and 100 pF. 4. Assumes that tRCD ≥ tRCD (max) and tRAD ≤ tRAD (max). 5. Assumes that tRCD ≤ tRCD (max) and tRAD ≥ tRAD (max). 6. tOFF (max) defines the time at which the output achieves the open circuit condition and is not referred to output voltage levels. 7. VIH (min) and VIL (max) are reference levels for measuring timing of input signals. Also, transition times are measured between VIH and VIL. 8. Operation with the tRCD (max) limit insures that tRAC (max) can be met, tRCD (max) is specified as a reference point only, if tRCD is greater than the specified tRCD (max) limit, then access time is controlled exclusively by tCAC. 9. Operation with the tRAD (max) limit insures that tRAC (max) can be met, tRAD (max) is specified as a reference point only, if tRAD is greater than the specified tRAD (max) limit, then access time is controlled exclusively by tAA. 10. tWCS, tRWD, tCWD, tCPW and tAWD are not restrictive operating parameters. They are included in the data sheet as electrical characteristics only; if tWCS ≥ tWCS (min), the cycle is an early write cycle and the data out pin will remain open circuit (high impedance) throughout the entire cycle; if tRWD ≥ tRWD (min), tCWD ≥ tCWD (min), tCPW ≥ tCPW (min) and tAWD ≥ tAWD (min), the cycle is a read-modify-write and the data output will contain data read from the selected cell; if neither of the above sets of conditions is satisfied, the condition of the data out (at access time) is indeterminate. 11. These parameters are referred to CAS leading edge in an early write cycle and to WE leading edge in a delayed write or read-modify-write cycle. 12. tRASC defines RAS pulse width in fast page mode cycles. 13. Access time is determined by the longest among tAA, tCAC and tACP. 14. An initial pause of 100 µs is required after power up followed by a minimum of eight initialization cycles (RAS-only refresh cycle or CAS-before-RAS refresh cycle). If the internal refresh counter is used, a minimum of eight CAS-before-RAS refresh cycles is required. 15. In delayed write or read-modify-write cycles, OE must disable output buffer prior to applying data to the device. 16. Test mode operation specified in this data sheet is 2-bit test function controlled by control address bits - - - CA0. This test mode operation can be performed by WE-and-CAS-before-RAS (WCBR) refresh cycle. Refresh during test mode operation will be performed by normal read cycles or by WCBR refresh cycles. When the state of two test bits accord each other, the condition of the output data is high level. When the state of test bits do not accord, the condition of the output data is low level. In order to end this test mode operation, perform a RAS-only refresh cycle or a CAS-before-RAS refresh cycle. 17. In a test mode read cycle, the value of tRAC, tAA, tCAC, tOAC and tACP is delayed for 2 ns to 5 ns for the specified value. These parameters should be specified in test mode cycles by adding the above value to the specified value in this data sheet. 18. Either tRCH or tRRH must be satisfied 19. tRAS (min) = tRWD (min) + tRWL (min) + tT in read-modify-write cycle. 20. tCAS (min) = tCWD (min) + tCWL (min) + tT in read-modify-write cycle. 13 HM514400B/BL, HM514400C/CL Series Timing Waveforms*21 Read Cycle t RC t RAS RAS tT t RP t CRP t RSH t CAS t CSH t RCD CAS t RAD t ASR Address t RAH t RAL t CAH t ASC Row Column t RCS t RCH t RRH WE t CAC t AA t OFF1 Dout Dout t RAC t OFF2 t DZC t OAC t CDD High-Z Din t ODD t DZO t OEP @ À À@ OE Notes: 21. H or L (H: VIH (min) ≤ VIN ≤ VIH (max), L: VIL (min) ≤ VIN ≤ VIL (max)) Invalid Dout 14 HM514400B/BL, HM514400C/CL Series Early Write Cycle t RC t RAS RAS t RP t RSH t CAS tT t RCD t CRP t CSH CAS t ASR Address t RAH t ASC Row t CAH Column t WCS t WCH WE t DH t DS Din Dout Din High-Z* * t WCS t WCS (min) ** OE : H or L 15 HM514400B/BL, HM514400C/CL Series Delayed Write Cycle t RC t RAS t RP RAS t CSH t CRP t RCD t RSH t CAS tT CAS t ASR Address t ASC t RAH t CWL t RWL t CAH Row Column t RCS t WP WE t DS t DH High-Z Din Din t DZC t ODD t OEH t DZO Dout Invalid Dout* t OFF2 OE * * Invalid Dout comes out, when OE is low level. 16 HM514400B/BL, HM514400C/CL Series Read-Modify-Write Cycle t RWC t RAS t RP RAS tT t RCD t CAS t CRP CAS t RAD t ASR Address t RAH tCAH t ASC Column Row t CWL t CWD t RCS t RWL t AWD t WP WE t RWD t AA t CAC t DS t RAC t DH t DZC High-Z Din Dout Din Dout t OAC t OFF2 t DZO OE t OEH t ODD t OEP 17 HM514400B/BL, HM514400C/CL Series Hidden Refresh Cycle tRC t RC t RP t RAS (Read) t RC t RAS t RP (Refresh) t RAS tRP (Refresh) RAS tT t RSH t CHR t CRP t CAS t RCD CAS t ASC t ASR t RAD t RAL t CAH t RAH Address Row Column t RCH t RRH t RCS t CAC WE t AA t OFF1 t RAC Dout Dout t DZC t OFF2 High-Z Din tDZO OE 18 t CDD t OAC t ODD HM514400B/BL, HM514400C/CL Series Fast Page Mode Read Cycle t RASC t RHCP t RP RAS tT t CSH t RCD t PC t CAS t CP t RSH t CAS t CP t CRP t CAS CAS t RAL t ASR t RAD t RAH Address tASC Row t ASC t CAH t CAH Column Column Column t RCS t RCS t CAH t ASC t RCS t RRH t RCH t RCH t RCH WE t DZC Din t RAC t DZC t DZC t CDD High-Z High-Z t ODD t CAC tCAC t CAC t AA t ACP t AA t AA Dout Dout t OAC OE t OFF2 t OEP High-Z t OFF1 t OFF1 t DZO Dout t DZO t ODD t ACP t OFF1 t DZO t CDD t CDD Dout t ODD t OAC t OFF2 t OFF2 t OEP t OEP t OAC 19 HM514400B/BL, HM514400C/CL Series Fast Page Mode Early Write Cycle t RASC t RP RAS tT t CSH t RCD t RSH t PC t CAS t CP t CAS t CAS t CP t CAH t ASC t CRP CAS t ASR Address t RAH Row t ASC t CAH Column t WCS t WCH t ASC Column t WCS t CAH Column t WCH t WCH t WCS WE t DS Din Dout Din t DH t DS Din t DH t DS t DH Din High-Z * OE : H or L 20 HM514400B/BL, HM514400C/CL Series Fast Page Mode Delayed Write Cycle t RASC t RP RAS tT t CSH tRCD t PC t CAS t CP t CAS t RSH t CAS t CP t CRP CAS t ASR t RAH Address t ASC t CAH t ASC t CAH Row t CAH t ASC Column Column Column t CWL t CWL t CWL t WP t RCS t WP t WP t RWL WE t DH t DS Din t RCS t DH t DS t DH t DS Din Din t RCS Din t OEH High-Z Dout t ODD OE 21 HM514400B/BL, HM514400C/CL Series Fast Page Mode Read-Modify-Write Cycle t RP t RASC RAS t RCD t PCM tT t CAS CAS t CRP t CP t CP t CAS t CAS t RAD t RAH t ASR Address t ACP t CAH t ASC t ASC Row t ASC Column Column t RCS t CAH t CAH t AWD t CWD t CWL t RWD t WP Column t AWD t CWL t CWD t RCS t CPW t WP t RCS t CPW t CWL t AWD t RWL t CWD t WP WE t CAC t DZC t DZC t CAC t DH High-Z Din High-Z Din tAA Din t OEH Dout t OAC t OEH Dout t OFF2 t DS t DH t DZC High-Z Din t CAC t DZO tOAC t DZO t DH t AA t RAC Dout t ACP t DS t DS t AA t OAC t OEH Dout t OFF2 t DZO t OFF2 OE t ODD t ODD t OEP 22 t OEP t ODD tOEP HM514400B/BL, HM514400C/CL Series Test Mode Cycle Set Cycle** *,** Reset Cycle Test Mode Cycle Normal Mode RAS CAS WE * CBR or RAS-only refresh ** Address, Din, OE: H or L Test Mode Set Cycle WE-and-CAS-Before RAS-Refresh Cycle t RC t RP t RAS t RP RAS t RPC t CSR t CHR t RPC t CRP CAS t WS t WH t CPN t CPN@ À@À@ tT WE Address t OFF1 Dout High-Z 23 HM514400B/BL, HM514400C/CL Series CAS-Before-RAS Refresh Cycle t RC t RP t RAS t RP RAS tT t CPN CAS t CSR t RPC t CHR t CPN t RPC t WS t WH WE Address t OFF1 Dout 24 High-Z t CRP HM514400B/BL, HM514400C/CL Series RAS-Only Refresh Cycle t RC t RAS t RP RAS tT t CRP tRPC tCRP CAS t RAH t ASR Address Dout Row High-Z * Refresh address : A0 – A9 (AX0 – AX9) ** WE : H or L 25 HM514400B/BL, HM514400C/CL Series CAS-Before-RAS Refresh Counter Check Cycle (Read) t RAS t RP RAS tT t CSR t CHR t CPT t RSH tCRP t CAS CAS t ASC t CAH Column Address t RCH t RRH t WS t WH t RCS WE t CDD t DZC High-Z Din t CAC t AA t OFF1 Dout Dout t DZO t OFF2 t OAC t OEP OE 26 t ODD HM514400B/BL, HM514400C/CL Series CAS-Before-RAS Refresh Counter Check Cycle (Write) t RAS t RP RAS tT t CSR t CHR t CPT t RSH t CRP t CAS CAS t ASC t CAH Address Column t WS t WH t WCS t WCH WE t DS Din Dout t DH Din High-Z OE 27