MOSEL VITELIC PRELIMINARY V53C8256H ULTRA-HIGH SPEED, 256K x 8 FAST PAGE MODE CMOS DYNAMIC RAM HIGH PERFORMANCE 35 40 45 50 Max. RAS Access Time, (tRAC) 35 ns 40 ns 45 ns 50 ns Max. Column Address Access Time, (tCAA) 18 ns 20 ns 22 ns 24 ns Min. Fast Page Mode Cycle Time, (tPC) 21 ns 23 ns 25 ns 28 ns Min. Read/Write Cycle Time, (tRC) 70 ns 75 ns 80 ns 90 ns Features Description ■ 256K x 8-bit organization ■ Fast Page Mode for a sustained data rate of 47 MHz ■ RAS access time: 35, 40, 45, 50 ns ■ Low power dissipation ■ Read-Modify-Write, RAS-Only Refresh, CAS-Before-RAS Refresh capability ■ Refresh Interval: 512 cycles/8 ms ■ Single 5V ± 10% Power Supply ■ Available in 24-pin 300 mil Plastic DIP, 26/24-pin 300 mil SOJ, and 28-pin TSOP-I packages The V53C8256H is a high speed 262,144 x 8 bit CMOS dynamic random access memory. The V53C8256H offers a combination of features: Fast Page Mode for high data bandwidth, fast usable speed, CMOS standby current. All inputs and outputs are TTL compatible. Input and output capacitances are significantly lowered to allow increased system performance. Fast Page Mode operation allows random access of up to 512 (x8) bits within a row with cycle times as short as 21 ns. Because of static circuitry, the CAS clock is not in the critical timing path. The flow-through column address latches allow address pipelining while relaxing many critical system timing requirements for fast usable speed. These features make the V53C8256H ideally suited for graphics, digital signal processing and high performance computing systems. Device Usage Chart Operating Temperature Range P K T 0°C to 70 °C • • • V53C8256H Rev. 1.2 July 1997 Package Outline Access Time (ns) Power 50 60 70 Std. Temperature Mark • • • • Blank 1 V53C8256H MOSEL VITELIC V 5 3 C 8 2 FAMILY Description Pkg. Pin Count Plastic DIP P 24 SOJ K 26/24 TSOP-I T 28 5 6 DEVICE 1 2 3 4 5 6 7 8 9 10 11 12 24 23 22 21 20 19 18 17 16 15 14 13 PKG SPEED ( t RAC) P (PLASTIC DIP) K (SOJ) T (TSOP-I) 24-Pin Plastic DIP PIN CONFIGURATION Top View VSS I/O1 I/O2 I/O3 I/O4 WE RAS A0 A1 A2 A3 VDD H TEMP. PWR. BLANK (0°C to 70°C) BLANK (NORMAL) 35 40 45 50 (35 ns) (40 ns) (45 ns) (50 ns) 26/24-Pin SOJ PIN CONFIGURATION Top View VSS I/O8 I/O7 I/O6 I/O5 CAS OE A8 A7 A6 A5 A4 8256H-02 VSS I/O1 I/O2 I/O3 I/O4 WE 1 2 3 4 5 6 27 26 24 23 22 21 VSS I/O8 I/O7 I/O6 I/O5 CAS RAS A0 A1 A2 A3 VDD 8 9 10 11 12 13 19 18 17 16 15 14 OE A8 A7 A6 A5 A4 8256H-03 28-Pin TSOP-I PIN CONFIGURATION Top View V53C8256H Rev. 1.2 July 1997 8256H-01 Pin Names 2 A0–A8 Address Inputs RAS Row Address Strobe CAS Column Address Strobe WE Write Enable OE Output Enable I/O1–I/O8 Data Input, Output VDD +5V Supply VSS 0V Supply NC No Connect V53C8256H MOSEL VITELIC Absolute Maximum Ratings* Capacitance* Ambient Temperature Under Bias .............................. –10°C to +80°C Storage Temperature (plastic) ...... -55°C to +125°C Voltage Relative to VSS ...................–1.0V to +7.0V Data Output Current ..................................... 50 mA Power Dissipation .......................................... 1.0 W TA = 25°C, VDD = 5 V ± 10%, VSS = 0 V *Note: Operation above Absolute Maximum Ratings can adversely affect device reliability. *Note: Capacitance is sampled and not 100% tested. Symbol Parameter Min. Max. CIN1 Unit Address Input 3 4 pF CIN2 RAS, CAS, WE, OE 4 5 pF COUT Data Input/Output 5 7 pF Block Diagram 256K x 8 OE WE CAS RAS RAS CLOCK GENERATOR CAS CLOCK GENERATOR WE CLOCK GENERATOR OE CLOCK GENERATOR VDD VSS I/O 1 DATA I/O BUS I/O 2 COLUMN DECODERS Y0 -Y8 SENSE AMPLIFIERS I/O 3 I/O BUFFER I/O 6 REFRESH COUNTER I/O 7 I/O 8 512 x 8 • • • A 7 A8 V53C8256H Rev. 1.2 July 1997 X 0 -X8 ROW DECODERS A1 ADDRESS BUFFERS AND PREDECODERS 9 A0 I/O 4 I/O 5 512 MEMORY ARRAY 8256H-05 3 V53C8256H MOSEL VITELIC DC and Operating Characteristics (1-2) TA = 0°C to 70°C, VCC = 5 V ± 10%, VSS = 0 V, unless otherwise specified. V53C8256H Symbol Parameter Access Time Min. Typ. Max. Unit Test Conditions Notes ILI Input Leakage Current (any input pin) –10 10 µA VSS ≤ VIN ≤ VCC ILO Output Leakage Current (for High-Z State) –10 10 µA VSS≤ VOUT ≤ VCC RAS, CAS at VIH ICC1 VCC Supply Current, Operating 35 160 mA tRC = tRC (min.) 40 150 45 145 50 135 4 mA RAS, CAS at VIH other inputs ≥ VSS 35 160 mA tRC = tRC (min.) 2 40 150 45 145 50 135 35 95 mA Minimum Cycle 1, 2 40 90 45 85 50 80 ICC2 VCC Supply Current, TTL Standby ICC3 VCC Supply Current, RAS-Only Refresh ICC4 VCC Supply Current, Fast Page Mode Operation 1, 2 ICC5 VCC Supply Current, Standby, Output Enabled 2 mA RAS = VIH, CAS = VIL, other inputs ≥ VSS ICC6 VCC Supply Current, CMOS Standby 1 mA RAS ≥ VCC – 0.2 V, CAS ≥ VCC – 0.2 V, All other inputs ≥ VSS VIL Input Low Voltage –1 0.8 V 3 VIH Input High Voltage 2.4 VCC + 1 V 3 VOL Output Low Voltage 0.4 V IOL = 4.2 mA VOH Output High Voltage V IOH = –5 mA V53C8256H Rev. 1.2 July 1997 2.4 4 1 V53C8256H MOSEL VITELIC AC Characteristics TA = 0°C to 70°C, VCC = 5 V ±10%, VSS = 0V unless otherwise noted AC Test conditions, input pulse levels 0 to 3V 35 40 45 50 # JEDEC Symbol Symbol Parameter 1 tRL1RH1 tRAS RAS Pulse Width 35 2 tRL2RL2 tRC Read or Write Cycle Time 70 75 80 90 ns 3 tRH2RL2 tRP RAS Precharge Time 25 25 25 30 ns 4 tRL1CH1 tCSH CAS Hold Time 35 40 45 50 ns 5 tCL1CH1 tCAS CAS Pulse Width 12 12 13 14 ns 6 tRL1CL1 tRCD RAS to CAS Delay 16 7 tWH2CL2 tRCS Read Command Setup Time 0 0 0 0 ns 8 tAVRL2 tASR Row Address Setup Time 0 0 0 0 ns 9 tRL1AX tRAH Row Address Hold Time 6 7 8 9 ns 10 tAVCL2 tASC Column Address Setup Time 0 0 0 0 ns 11 tCL1AX tCAH Column Address Hold Time 4 5 6 7 ns 12 tCL1RH1(R) tRSH (R) RAS Hold Time (Read Cycle) 12 12 13 14 ns 13 tCH2RL2 tCRP CAS to RAS Precharge Time 5 5 5 5 ns 14 tCH2WX tRCH Read Command Hold Time Referenced to CAS 0 0 0 0 ns 5 15 tRH2WX tRRH Read Command Hold Time Referenced to RAS 0 0 0 0 ns 5 16 tOEL1RH2 tROH RAS Hold Time Referenced to OE 8 8 9 10 ns 17 tGL1QV tOAC Access Time from OE 12 12 13 14 ns 18 tCL1QV tCAC Access Time from CAS 12 12 13 14 ns 6, 7 19 tRL1QV tRAC Access Time from RAS 35 40 45 50 ns 6, 8, 9 20 tAVQV tCAA Access Time from Column Address 18 20 22 24 ns 6, 7, 10 21 tCL1QX tLZ OE or CAS to Low-Z Output 0 ns 16 22 tCH2QZ tHZ OE or CAS to High-Z Output 0 ns 16 23 tRL1AX tAR Column Address Hold Time from RAS 28 24 tRL1AV tRAD RAS to Column Address Delay Time 11 25 tCL1RH1(W) tRSH (W) RAS or CAS Hold Time in Write Cycle 12 12 13 14 ns 26 tWL1CH1 tCWL Write Command to CAS Lead Time 12 12 13 14 ns 27 tWL1CL2 tWCS Write Command Setup Time 0 0 0 0 ns 28 tCL1WH1 tWCH Write Command Hold Time 5 5 6 7 ns V53C8256H Rev. 1.2 July 1997 Min. Max. Min. Max. Min. Max. Min. Max. Unit 5 75K 23 40 17 75K 28 0 6 0 12 18 75K 32 0 6 30 17 45 0 13 19 75K 36 0 7 35 20 50 0 8 40 23 14 Notes ns ns 4 ns 26 ns 11 12, 13 V53C8256H MOSEL VITELIC AC Characteristics (Cont’d) 35 40 45 50 # JEDEC Symbol Symbol Parameter 29 tWL1WH1 tWP Write Pulse Width 5 5 6 7 ns 30 tRL1WH1 tWCR Write Command Hold Time from RAS 28 30 35 40 ns 31 tWL1RH1 tRWL Write Command to RAS Lead Time 12 12 13 14 ns 32 tDVWL2 tDS Data in Setup Time 0 0 0 0 ns 14 33 tWL1DX tDH Data in Hold Time 4 5 6 7 ns 14 34 tWL1GL2 tWOH Write to OE Hold Time 5 6 7 8 ns 14 35 tGH2DX tOED OE to Data Delay Time 5 6 7 8 ns 14 36 tRL2RL2 (RMW) tRWC Read-Modify-Write Cycle Time 105 110 115 130 ns 37 tRL1RH1 (RMW) tRRW Read-Modify-Write Cycle RAS Pulse Width 70 75 80 87 ns 38 tCL1WL2 tCWD CAS to WE Delay 28 30 32 34 ns 12 39 tRL1WL2 tRWD RAS to WE Delay in ReadModify-Write Cycle 54 58 62 68 ns 12 40 tCL1CH1 tCRW CAS Pulse Width (RMW) 46 48 50 52 ns 41 tAVWL2 tAWD Col. Address to WE Delay 35 38 41 42 ns 42 tCL2CL2 tPC Fast Page Mode 21 23 25 28 ns Min. Max. Min. Max. Min. Max. Min. Max. Unit Notes 12 Read or Write Cycle Time 43 tCH2CL2 tCP CAS Precharge Time 4 5 6 7 ns 44 tAVRH1 tCAR Column Address to RAS Setup Time 18 20 22 24 ns 45 tCH2QV tCAP Access Time from Column Precharge 46 tRL1DX tDHR Data in Hold Time Referenced to RAS 28 30 35 40 ns 47 tCL1RL2 tCSR CAS Setup Time CAS-before-RAS Refresh 10 10 10 10 ns 48 tRH2CL2 tRPC RAS to CAS Precharge Time 0 0 0 0 ns 49 tRL1CH1 tCHR CAS Hold Time CAS-before-RAS Refresh 8 8 10 12 ns 50 tCL2CL2 (RMW) tPCM Fast Page Mode Read-ModifyWrite Cycle Time 58 60 65 70 ns tT tT Transition Time (Rise and Fall) 3 tREF Refresh Interval (512 Cycles) V53C8256H Rev. 1.2 July 1997 20 50 8 6 22 3 50 8 24 3 50 8 27 3 ns 7 50 ns 15 8 ms 17 V53C8256H MOSEL VITELIC Notes: 1. ICC is dependent on output loading when the device output is selected. Specified ICC (max.) is measured with the output open. 2. ICC is dependent upon the number of address transitions. Specified ICC (max.) is measured with a maximum of two transitions per address cycle in Fast Page Mode. 3. Specified VIL (min.) is steady state operating. During transitions, VIL (min.) may undershoot to –1.0 V for a period not to exceed 20 ns. All AC parameters are measured with VIL (min.) ≥ VSS and VIH (max.) ≤ VCC. 4. tRCD (max.) is specified for reference only. Operation within tRCD (max.) limits insures that tRAC (max.) and tCAA (max.) can be met. If tRCD is greater than the specified tRCD (max.), the access time is controlled by tCAA and tCAC. 5. Either tRRH or tRCH must be satisified for a Read Cycle to occur. 6. Measured with a load equivalent to two TTL inputs and 50 pF. 7. Access time is determined by the longest of tCAA, tCAC and tCAP. 8. Assumes that tRAD ≤ tRAD (max.). If tRAD is greater than tRAD (max.), tRAC will increase by the amount that tRAD exceeds tRAD (max.). 9. Assumes that tRCD ≤ tRCD (max.). If tRCD is greater than tRCD (max.), tRAC will increase by the amount that tRCD exceeds tRCD (max.). 10. Assumes that tRAD ≥ tRAD (max.). 11. Operation within the tRAD (max.) limit ensures 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, the access time is controlled by tCAA and tCAC. 12. tWCS, tRWD, tAWD and tCWD are not restrictive operating parameters. 13. tWCS (min.) must be satisfied in an Early Write Cycle. 14. tDS and tDH are referenced to the latter occurrence of CAS or WE. 15. tT is measured between VIH (min.) and VIL (max.). AC-measurements assume tT = 3 ns. 16. Assumes a three-state test load (5 pF and a 380 Ohm Thevenin equivalent). 17. An initial 200 µs pause and 8 RAS-containing cycles are required when exiting an extended period of bias without clocks. An extended period of time without clocks is defined as one that exceeds the specified Refresh Interval. V53C8256H Rev. 1.2 July 1997 7 V53C8256H MOSEL VITELIC Waveforms of Read Cycle t RC (2) t RAS (1) RAS t RP (3) tAR (23) VIH VIL t CSH (4) t CRP (13) CAS t RCD (8) VIL t CRP (13) t RAD (24) t RAH (9) tASR (8) ADDRESS t RSH (R)(12) t CAS (5) VIH VIH ROW ADDRESS VIL t CAH (11) t ASC (10) COLUMN ADDRESS t RCH (14) t CAR (44) t RCS (7) WE t ROH (15) VIH VIL t ROH (16) t CAA (20) OE tOAC (17) VIH V IL t CAC (18) tRAC (19) I/O tHZ (22) t HZ (22) VOH VALID DATA-OUT VOL 8256H-06 t LZ (21) Waveforms of Early Write Cycle t RC (2) t RAS (1) RAS t RP (3) tAR (23) VIH V IL t CSH (4) tCRP (13) t RCD (6) t RSH (W)(25) t CAS (5) VIH CAS V IL t CAR (44) t CAH (11) t RAH (9) tASR (8) ADDRESS t CRP (13) VIH V IL tASC (10) ROW ADDRESS COLUMN ADDRESS t WCH (28) t RAD (24) t CWL (26) WE t WP(29) tWCS (27) VIH V IL t WCR (30) t RWL (31) OE VIH V IL t DHR (46) tDS (32) I/O VIH V IL tDH (33) VALID DATA-IN HIGH-Z 8256H-07 Don’t Care V53C8256H Rev. 1.2 July 1997 8 Undefined V53C8256H MOSEL VITELIC Waveforms of Write Cycle (OE Controlled Write) t RC (2) tRAS (1) RAS V IL t CSH (4) t CRP (13) t RCD (6) t RSH (W)(12) tCAS (5) VIH CAS t CRP (13) V IL tRAD (24) t RAH (9) tASR (8) ADDRESS t RP (3) t AR (23) VIH VIH tASC (10) ROW ADDRESS V IL t CAR (44) t CAH (11) COLUMN ADDRESS t CWL (26) t RWL (31) t WP(29) WE VIH V IL t WOH (34) OE VIH V IL t OED (35) I/O tDH (33) t DS (32) VIH VALID DATA-IN V IL 8256H-09 Waveforms of Read-Modify-Write Cycle tRWC (36) tRRW (37) RAS tRP (3) tAR (23) VIH VIL t CSH (4) t CRP (13) tRCD (6) tRSH (W)(25) t CRW (40) VIH CAS VIL tCAH (11) tRAH (9) tASC (10) tASR (8) ADDRESS VIH ROW ADDRESS VIL COLUMN ADDRESS tAWD (41) tCWD (38) t RAD (24) tRWD (39) WE OE tCRP (13) t CWL (26) tRWL (31) tWP(29) VIH VIL t CAA (20) t OAC (17) VIH VIL t OED (35) tCAC (18) tRAC (19) I/O VIH VOH VIL VOL tDH (33) tHZ (22) t DS (32) VALID DATA-OUT VALID DATA-IN 8256H-09 tLZ (21) Don’t Care V53C8256H Rev. 1.2 July 1997 9 Undefined V53C8256H MOSEL VITELIC Waveforms of Fast Page Mode Read Cycle RAS tPC (42) tCP(43) tCSH (4) t RAH (9) tCAR (44) tASC (10) t CAH (11) tASC (10) VIH ROW ADDRESS COLUMN ADDRESS t RCH (14) t CAH (11) t CAH (11) COLUMN ADDRESS COLUMN ADDRESS t RCS (7) t RCS (7) t RCS (7) V IL tCAA (20) t CAA (20) t CAP (45) t OAC (17) tRRH (15) t OAC (17) VIH V IL tHZ (22) tRAC (19) tCAC (18) t LZ (21) t CAC (18) tCAC (18) t HZ (22) VOH tHZ (22) tHZ (22) VALID DATA OUT VOL tHZ (22) tHZ (22) t LZ (21) t LZ (21) I/O tRCH (14) VIH t OAC (17) OE t CRP (13) t CAS (5) tCAS (5) V IL V IL WE tRSH (R)(12) t CAS (5) VIH tASR (8) ADDRESS RP (3) V IL t RCD (6) tCRP (13) CAS t t RAS (1) tAR (23) VIH VALID DATA OUT VALID DATA OUT 8256H-10 Waveforms of Fast Page Mode Write Cycle tRP (3) tAR (23) RAS t RAS (1) VIH V IL t CRP (13) tRCD (6) CAS t PC (42) t CP(43) t CAS (5) VIH t RSH (W)(25) t CRP (13) tCAS (5) tCAS (5) V IL tCSH (4) tRAH (9) t CAR (44) tASC (10) t ASR (8) ADDRESS VIH ROW ADD V IL tASC (10) tCAH (11) tCAH (11) COLUMN ADDRESS tRAD (24) COLUMN ADDRESS t CWL (26) t CWL (26) t WCS (27) t WCS (27) tCWL (26) t WCS (27) t WCH (28) t WCH (28) t WP (29) WE t CAH (11) COLUMN ADDRESS t WP(29) tRWL(31) t WCH (28) tWP(29) tDS (32) tDH (33) tDH (33) VIH V IL OE VIH VIL tDS (32) t DH (33) t DS (32) I/O VIH V IL VALID DATA IN VALID DATA IN OPEN VALID DATA IN OPEN 8256H-11 Don’t Care V53C8256H Rev. 1.2 July 1997 10 Undefined V53C8256H MOSEL VITELIC Waveforms of Fast Page Mode Read-Write Cycle tRAS (1) VIH RAS V IL t CSH (4) tRP (3) tRCD (6) tPCM (50) t RSH (W)(25) t CRP (13) t CAS (5) t CP(43) t CAS (5) V IH CAS V t CAS (5) t RAD (24) IL tRAH (9) t CAR (44) tASC (10) tASC (10) tASR (8) V IH ADDRESS tCAH (11) IL tCAH (11) COLUMN ADDRESS ROW ADD V tASC (10) t CAH (11) COLUMN ADDRESS tRWD (39) COLUMN ADDRESS tCWD (38) t RCS (7) t CWD (38) tRWL(31) tCWL (26) t CWL (26) t CWD (38) t CWL (26) V IH WE V IL tAWD (41) tAWD (41) tAWD (41) t WP(29) t CAA (20) t OAC (17) tWP(29) tWP(29) t OAC (17) t OAC (17) V IH OE V IL tCAP (45) tCAP (45) t CAA (20) t CAA (20) tOED (35) tOED (35) t CAC (18) t RAC (19) t CAC (18) t HZ (22) tHZ (22) tDH (33) t DH (33) tDS (32) tDS (32) I/O VI/OH OUT VI/OL OUT IN tLZ (21) t LZ (21) t OED (35) tCAC (18) t HZ (22) tDH (33) tDS (32) OUT IN IN tLZ (21) 8256H-12 Waveforms of RAS Only Refresh Cycle t RC (2) RAS t RAS (1) V IH t RP (3) V IL t CRP (13) CAS V IH V IL t ASR (8) ADDRESS V IH t RAH (9) ROWADDR V IL 8256H-13 NOTE: WE, OE = Don’t care Don’t Care V53C8256H Rev. 1.2 July 1997 11 Undefined V53C8256H MOSEL VITELIC Waveforms of CAS-before-RAS Refresh Counter Test Cycle t RAS (1) RAS t RP (3) VIH V IL t CSR (47) CAS t CHR (49) t RSH (W)(25) tCAS (5) t CP(43) VIH V IL ADDRESS VIH V IL READ CYCLE WE t RRH (15) t RCH (14) t RCS (7) VIH V IL t ROH (16) t OAC (17) OE VIH V IL t HZ (22) t HZ (22) t LZ (21) I/O VIH DOUT V IL t RWL (31) t CWL (26) WRITE CYCLE WE t WCH (28) t WCS (27) VIH V IL OE VIH V IL tDS (32) I/O VIH t DH (33) D IN V IL 8256H-14 Waveforms of CAS-before-RAS Refresh Cycle t RC (2) t RP (3) RAS t RAS (1) t RP (3) VIH V IL t RPC (48) t CP (43) t CHR (49) t CSR (47) CAS VIH V IL t HZ (22) I/O VOH VOL 8256H-15 NOTE: WE, OE, A0–A7 = Don’t care Don’t Care V53C8256H Rev. 1.2 July 1997 12 Undefined V53C8256H MOSEL VITELIC Waveforms of Hidden Refresh Cycle (Read) tRC (2) RAS tRC (2) t RP (3) t RAS (1) tAR (23) VIH t RP (3) t RAS (1) V IL tRCD (6) t CRP (13) tRSH (R)(12) t CHR (49) tCRP (13) VIH CAS V IL tRAD (24) tASC (10) tASR (8) t RAH (9) ADDRESS VIH t CAH (11) COLUMN ADDRESS ROW ADD V IL tRCS (7) WE t RRH (15) VIH V IL t CAA (20) t OAC (17) OE VIH V IL t CAC (18) t LZ (21) t RAC (19) I/O t HZ (22) t HZ (22) VOH VALID DATA VOL 8256H-16 Waveforms of Hidden Refresh Cycle (Write) t RC (2) VIH RAS t RAS (1) tRP (3) V IL t RCD (6) t CRP (13) CAS t RC (2) tRP (3) t RAS (1) tAR (23) t RSH (12) t CHR (49) t CRP (13) VIH V IL tRAD (24) tASC (10) tASR (8) t RAH (9) ADDRESS VIH V IL t CAH (11) ROW ADD COLUMN ADDRESS t WCH (28) t WCS (27) WE VIH V IL VIH OE V IL t DS (32) VIH I/O V IL tDH (33) VALID DATA-IN t DHR (46) 8256H-17 Don’t Care V53C8256H Rev. 1.2 July 1997 13 Undefined V53C8256H MOSEL VITELIC Functional Description Refresh Cycle The V53C8256H is a CMOS dynamic RAM optimized for high data bandwidth, low power applications. It is functionally similar to a traditional dynamic RAM. The V53C8256H reads and writes data by multiplexing an 18-bit address into a 9-bit row and a 9-bit column address. The row address is latched by the Row Address Strobe (RAS). The column address “flows through” an internal address buffer and is latched by the Column Address Strobe (CAS). Because access time is primarily dependent on a valid column address rather than the precise time that the CAS edge occurs, the delay time from RAS to CAS has little effect on the access time. To retain data, 512 Refresh Cycles are required in each 8 ms period. There are two ways to refresh the memory: 1. By clocking each of the 512 row addresses (A0 through A8) with RAS at least once every 8 ms. Any Read, Write, Read-Modify-Write or RASonly cycle refreshes the addressed row. 2. Using a CAS-before-RAS Refresh Cycle. If CAS makes a transition from low to high to low after the previous cycle and before RAS falls, CASbefore-RAS refresh is activated. The V53C8256H uses the output of an internal 9-bit counter as the source of row addresses and ignore external address inputs. Memory Cycle A memory cycle is initiated by bringing RAS low. Any memory cycle, once initiated, must not be ended or aborted before the minimum tRAS time has expired. This ensures proper device operation and data integrity. A new cycle must not be initiated until the minimum precharge time tRP/tCP has elapsed. CAS-before-RAS is a “refresh-only” mode and no data access or device selection is allowed. Thus, the output remains in the High-Z state during the cycle. A CAS-before-RAS counter test mode is provided to ensure reliable operation of the internal refresh counter. Read Cycle Fast Page Mode Operation A Read cycle is performed by holding the Write Enable (WE) signal High during a RAS/CAS operation. The column address must be held for a minimum specified by tAR. Data Out becomes valid only when tOAC, tRAC, tCAA and tCAC are all satisifed. As a result, the access time is dependent on the timing relationships between these parameters. For example, the access time is limited by tCAA when tRAC, tCAC and tOAC are all satisfied. Fast Page Mode operation permits all 512 columns within a selected row of the device to be randomly accessed at a high data rate. Maintaining RAS low while performing successive CAS cycles retains the row address internally and eliminates the need to reapply it for each cycle. The column address buffer acts as a transparent or flow-through latch while CAS is high. Thus, access begins from the occurrence of a valid column address rather than from the falling edge of CAS, eliminating tASC and tT from the critical timing path. CAS latches the address into the column address buffer and acts as an output enable. During Fast Page Mode operation, Read, Write, Read-Modify-Write or ReadWrite-Read cycles are possible at random addresses within a row. Following the initial entry cycle into Fast Page Mode, access is tCAA or tCAP controlled. If the column address is valid prior to the rising edge of CAS, the access time is referenced to the CAS rising edge and is specified by tCAP. If the column address is valid after the rising CAS edge, access is timed from the occurrence of a valid address and is specified by tCAA. In both cases, the falling edge of CAS latches the address and enables the output. Write Cycle A Write Cycle is performed by taking WE and CAS low during a RAS operation. The column address is latched by CAS. The Write Cycle can be WE controlled or CAS controlled depending on whether WE or CAS falls later. Consequently, the input data must be valid at or before the falling edge of WE or CAS, whichever occurs last. In the CAScontrolled Write Cycle, when the leading edge of WE occurs prior to the CAS low transition, the I/O data pins will be in the High-Z state at the beginning of the Write function. Ending the Write with RAS or CAS will maintain the output in the High-Z state. In the WE controlled Write Cycle, OE must be in the high state and tOED must be satisfied. V53C8256H Rev. 1.2 July 1997 14 V53C8256H MOSEL VITELIC During Power-On, the VDD current requirement of the V53C8256H is dependent on the input levels of RAS and CAS. If RAS is low during Power-On, the device will go into an active cycle and IDD will exhibit current transients. It is recommended that RAS and CAS track with VDD or be held at a valid VIH during Power-On to avoid current surges. Fast Page Mode provides a sustained data rate of 47 MHz for applications that require high data rates such as bit-mapped graphics or high-speed signal processing. The following equation can be used to calculate the maximum data rate: 512 Data Rate = ---------------------------------------t RC + 511 × t PC Table 1. V53C8256H Data Output Data Output Operation Operation for Various Cycle Types The V53C8256H Input/Output is controlled by OE, CAS, WE and RAS. A RAS low transition enables the transfer of data to and from the selected row address in the Memory Array. A RAS high transition disables data transfer and latches the output data if the output is enabled. After a memory cycle is initiated with a RAS low transition, a CAS low transition or CAS low level enables the internal I/O path. A CAS high transition or a CAS high level disables the I/O path and the output driver if it is enabled. A CAS low transition while RAS is high has no effect on the I/O data path or on the output drivers. The output drivers, when otherwise enabled, can be disabled by holding OE high. The OE signal has no effect on any data stored in the output latches. A WE low level can also disable the output drivers when CAS is low. During a Write cycle, if WE goes low at a time in relationship to CAS that would normally cause the outputs to be active, it is necessary to use OE to disable the output drivers prior to the WE low transition to allow Data In Setup Time (tDS) to be satisfied. Power-On After application of the VDD supply, an initial pause of 200 µs is required followed by a minimum of 8 initialization cycles (any combination of cycles containing a RAS clock). Eight initialization cycles are required after extended periods of bias without clocks (greater than the Refresh Interval). V53C8256H Rev. 1.2 July 1997 15 Cycle Type I/O State Read Cycles Data from Addressed Memory Cell CAS-Controlled Write Cycle (Early Write) High-Z WE-Controlled Write Cycle (Late Write) OE Controlled. High OE = High-Z I/Os Read-Modify-Write Cycles Data from Addressed Memory Cell Fast Page Mode Read Cycle Data from Addressed Memory Cell Fast Page Mode Write Cycle (Early Write) High-Z Fast Page Mode ReadModify-Write Cycle Data from Addressed Memory Cell RAS-only Refresh High-Z CAS-before-RAS Refresh Cycle Data remains as in previous cycle CAS-only Cycles High-Z V53C8256H MOSEL VITELIC Package Diagrams 24-Pin 300 mil PDIP 0.300 – 0.330 [7.62 – 8.38] 0.250 – 0.300 [6.35 – 7.62] .180 Max. [4.57 Max.] 1.310 Max. [33.27 Max.] Unit in inches [mm] 0.005 – 0.050 [0.127 – 1.27] 0.110 – 0.140 [2.79 – 3.56] .100 Typ. [2.54 Typ.] .008 – .013 [.203 – .330] 0.018 – 0.024 [0.457 – 0.610] 0.320 – 0.390 [8.13 – 9.91] 0.048 – 0.065 [1.22 – 1.65] 26/24-Pin 300 mil SOJ 0.332 – 0.342 [8.43 – 8.69] 0.296 – 0.304 [7.52 – 7.72] 0.665 – 0.698 [16.89 – 17.73] 0.125 – 0.135 [3.175 – 3.429] 0.082 – 0.093 [2.08 – 2.36] 0.028 Typ. [0.711 Typ.] V53C8256H Rev. 1.2 July 1997 0.05 Typ. [1.27 Typ.] 0.018 Typ. [0.457 Typ.] 0.025 Min. [0.635 Min.] 16 0.255 – 0.275 [6.477 – 6.985] Unit in inches [mm] V53C8256H MOSEL VITELIC 28-Pin TSOP-I Unit in inches [mm] .035 – .043 [.889 – 1.09] Detail “A” .520 – .535 [13.21 – 13.59] .039 DIA. [.991 DIA] .000 .079 DIA. x .0004 Deep .000 2.01 DIA. x .0102 Deep Fixed Pin (1 Plcs.) 0.10 (.004) [2.54 (.102)] .461 – .469 [11.71 – 11.91] .047 [1.19] .035 – .043 [.889 – 1.09] .002 – .006 [.051 – .152] 0.10 [2.54] .055 – .063 [1.40 – 1.60] .311 – .319 [7.90 – 8.10] .55 [13.97] .055 – .063 [1.40 – 1.60] 0.25 [6.35] 0.10 [2.54] Top View Bottom View .055 – .063 [1.40 – 1.60] See Detail “B” D .037 – .041 [.940 – 1.04] See Detail “A” D .008 – .20 [.203 – 5.08] .007 – .011 [.178 – .279] 0° – 6° Gage Plane .007 – .009 [.178 – .229] .012 MAX [.305 MAX] With Plating Base Metal .004 – .008 [.102 – .203] .020 – .028 [.508 – .711] .004 – .006 [.102 – .152] Detail “A” Section “D-D” V53C8256H Rev. 1.2 July 1997 17 0.25 BSC [6.35 BSC] Detail “B” MOSEL VITELIC WORLDWIDE OFFICES V53C8256H U.S.A. TAIWAN JAPAN 3910 NORTH FIRST STREET SAN JOSE, CA 95134 PHONE: 408-433-6000 FAX: 408-433-0185 7F, NO. 102 MIN-CHUAN E. ROAD, SEC. 3 TAIPEI PHONE: 011-886-2-545-1213 FAX: 011-886-2-545-1209 RM.302 ANNEX-G HIGASHI-NAKANO NAKANO-KU, TOKYO 164 PHONE: 011-81-03-3365-2851 FAX: 011-81-03-3365-2836 HONG KONG 19 DAI FU STREET TAIPO INDUSTRIAL ESTATE TAIPO, NT, HONG KONG PHONE: 011-852-665-4883 FAX: 011-852-664-7535 1 CREATION ROAD I SCIENCE BASED IND. PARK HSIN CHU, TAIWAN, R.O.C. PHONE: 011-886-35-783344 FAX: 011-886-35-792838 U.S. SALES OFFICES NORTHWESTERN SOUTHWESTERN CENTRAL & SOUTHEASTERN 3910 NORTH FIRST STREET SAN JOSE, CA 95134 PHONE: 408-433-6000 FAX: 408-433-0185 SUITE 200 5150 E. PACIFIC COAST HWY. LONG BEACH, CA 90804 PHONE: 310-498-3314 FAX: 310-597-2174 604 FIELDWOOD CIRCLE RICHARDSON, TX 75081 PHONE: 972-690-1402 FAX: 972-690-0341 NORTHEASTERN SUITE 436 20 TRAFALGAR SQUARE NASHUA, NH 03063 PHONE: 603-889-4393 FAX: 603-889-9347 © Copyright 1997, MOSEL VITELIC Inc. The information in this document is subject to change without notice. MOSEL VITELIC makes no commitment to update or keep current the information contained in this document. No part of this document may be copied or reproduced in any form or by any means without the prior written consent of MOSEL-VITELIC. MOSEL VITELIC 7/97 Printed in U.S.A. MOSEL VITELIC subjects its products to normal quality control sampling techniques which are intended to provide an assurance of high quality products suitable for usual commercial applications. MOSEL VITELIC does not do testing appropriate to provide 100% product quality assurance and does not assume any liability for consequential or incidental arising from any use of its products. If such products are to be used in applications in which personal injury might occur from failure, purchaser must do its own quality assurance testing appropriate to such applications. 3910 N. First Street, San Jose, CA 95134-1501 Ph: (408) 433-6000 Fax: (408) 433-0952 Tlx: 371-9461