E2L0024-17-Y1 ¡ Semiconductor MSM54V16272 ¡ Semiconductor This version: Jan. 1998 MSM54V16272 Previous version: Dec. 1996 262,144-Word ¥ 16-Bit Multiport DRAM DESCRIPTION The MSM54V16272 is a 4-Mbit CMOS multiport DRAM composed of a 262,144-word by 16-bit dynamic RAM, and a 512-word by 16-bit SAM. Its RAM and SAM operate independently and asynchronously. It supports three types of operations: random access to RAM port, high speed serial access to SAM port, and bidirectional transfer of data between any selected row in the RAM port and the SAM port. In addition to the conventional multiport DRAM operating modes, the MSM54V16272 features block write and flash write functions on the RAM port, and a split data transfer capability on the SAM port. The SAM port requires no refresh operation because it uses static CMOS flip-flops. FEATURES • Single power supply: 3.3 V ±0.3 V • RAS only refresh • Full TTL compatibility • CAS before RAS refresh • Multiport organization • CAS before RAS self-refresh RAM : 256K word ¥ 16 bits • Hidden refresh SAM : 512 word ¥ 16 bits • Serial read/write • Fast page mode • 512 tap location • Write per bit • Bidirectional data transfer • Byte read/write • Split transfer • Masked flash write • Masked write transfer • Masked block write (8 columns) • Refresh: 512 cycles/8 ms • Package options: 64-pin 525 mil plastic SSOP (SSOP64-P-525-0.80-K) (Product : MSM54V16272-xxGS-K) 70/64-pin 400 mil plastic TSOP (Type II)(TSOPII70/64-P-400-0.65-K)(Product : MSM54V16272-xxTS-K) xx indicates speed rank. PRODUCT FAMILY Family Access Time Cycle Time Power Dissipation RAM SAM RAM SAM Operating Standby MSM54V16272-60 60 ns 18 ns 120 ns 22 ns 160 mA 8 mA MSM54V16272-70 70 ns 20 ns 140 ns 22 ns 150 mA 8 mA 1/39 ¡ Semiconductor MSM54V16272 PIN CONFIGURATION (TOP VIEW) VCC TRG VSS SDQ0 DQ0 SDQ1 DQ1 VCC SDQ2 DQ2 SDQ3 DQ3 VSS SDQ4 DQ4 SDQ5 DQ5 VCC SDQ6 DQ6 SDQ7 DQ7 VSS CASL WE RAS A8 A7 A6 A5 A4 VCC 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 64 63 62 61 60 59 58 57 56 55 54 53 52 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 35 34 33 SC SE VSS SDQ15 DQ15 SDQ14 DQ14 VCC SDQ13 DQ13 SDQ12 DQ12 VSS SDQ11 DQ11 SDQ10 DQ10 VCC SDQ9 DQ9 SDQ8 DQ8 VSS DSF NC CASU QSF A0 A1 A2 A3 VSS 64-Pin Plastic SSOP Pin Name A0 - A8 Function Address Input VCC TRG VSS SDQ0 DQ0 SDQ1 DQ1 VCC SDQ2 DQ2 SDQ3 DQ3 VSS SDQ4 DQ4 SDQ5 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 SC SE VSS SDQ15 DQ15 SDQ14 DQ14 VCC SDQ13 DQ13 SDQ12 DQ12 VSS SDQ11 DQ11 SDQ10 DQ5 VCC SDQ6 DQ6 SDQ7 DQ7 VSS CASL WE RAS A8 A7 A6 A5 A4 VCC 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 51 50 49 48 47 46 45 44 43 42 41 40 39 38 37 36 DQ10 VCC SDQ9 DQ9 SDQ8 DQ8 VSS DSF NC CASU QSF A0 A1 A2 A3 VSS 70/64-Pin Plastic TSOP (II) (K Type) Pin Name Function SC Serial Clock DQ0 - DQ15 RAM Inputs/Outputs SE SAM Port Enable SDQ0 - SDQ15 SAM Inputs/Outputs DSF Special Function Input RAS Row Address Strobe QSF Special Function Output CASL Column Address Strobe Lower VCC Power Supply (3.3 V) CASU Note: Column Address Strobe Upper VSS Ground (0 V) WE Write Enable NC No Connection TRG Transfer/Output Enable The same power supply voltage must be provided to every VCC pin, and the same GND voltage level must be provided to every VSS pin. 2/39 Block Write Control Column Mask Register Sense Amp. I/O Control Color Register RAM Input Buffer Mask Register Buffer A0 - A8 Refresh Counter Row Decoder Row Address 512 ¥ 512 ¥ 16 RAM ARRAY Gate Gate SAM SAM Serial Decoder SAM Address Buffer ¡ Semiconductor Column Decoder BLOCK DIAGRAM Column Address Buffer DQ 0 - 15 RAM Output Buffer Flash Write Control SAM Input Buffer RAS CASU / CASL SDQ 0 - 15 SAM Output Buffer Timing Generator TRG WE DSF SC SAM Address Counter QSF SE SE VCC VSS 3/39 MSM54V16272 SAM Stop Control ¡ Semiconductor MSM54V16272 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings (Note: 1) Parameter Symbol Condition Rating Unit Input Output Voltage VT Ta = 25°C –0.5 to 4.6 V Output Current IOS Ta = 25°C 50 mA Power Dissipation PD Topr Ta = 25°C 1 W Operating Temperature — 0 to 70 °C Storage Temperature Tstg — –55 to 150 °C Recommended Operating Conditions (Ta = 0°C to 70°C) (Note: 2) Parameter Symbol Min. Typ. Max. Unit Power Supply Voltage VCC 3.0 Input High Voltage VIH 2.0 3.3 3.6 V — VCC + 0.3 V Input Low Voltage VIL –0.3 — 0.8 V Capacitance (VCC = 3.3 V ±0.3 V, f = 1 MHz, Ta = 25°C) Parameter Input Capacitance Input/Output Capacitance Output Capacitance Note: Symbol Min. Max. Unit Ci — 6 pF Cio — 7 pF Co(QSF) — 7 pF This parameter is periodically sampled and is not 100% tested. DC Characteristics 1 Symbol Condition Min. Max. Output "H" Level Voltage VOH IOH = –2 mA 2.4 — Output "L" Level Voltage VOL IOL = 2 mA — 0.4 Input Leakage Current ILI 0 £ VIN £ VCC All other pins not under test = 0 V –10 10 0 £ VOUT £ VCC Output Disable –10 Parameter Output Leakage Current ILO Unit V mA 10 4/39 ¡ Semiconductor MSM54V16272 DC Characteristics 2 (VCC = 3.3 V ±0.3 V, Ta = 0°C to 70°C) Item (RAM) Operating Current (RAS, CAS Cycling, tRC = tRC min.) Standby Current (RAS, CAS = VIH) RAS Only Refresh Current (RAS Cycling, CAS = VIH, tRC = tRC min.) Page Mode Current (RAS = VIL, CAS Cycling, tPC = tPC min.) CAS before RAS Refresh Current (RAS Cycling, CAS before RAS, tRC = tRC min.) Data Transfer Current (RAS, CAS Cycling, tRC = tRC min.) Flash Write Current (RAS, CAS Cycling, tRC = tRC min.) Block Write Current (RAS, CAS Cycling, tRC = tRC min.) CAS before RAS Self-Refresh Current (RAS, CAS £ 0.2 V) -60 -70 Max. Max. ICC1 120 110 3, 4 17 SAM Symbol Standby Active ICC1A 160 150 Standby ICC2 8 8 Unit Note Active ICC2A 55 55 3, 4 Standby ICC3 120 110 3, 4 Active ICC3A 160 150 17 Standby ICC4 120 110 3, 4 Active ICC4A 160 150 Standby ICC5 100 90 Active ICC5A 140 130 3, 4 Standby ICC6 110 100 3, 4 Active ICC6A 150 140 17 Standby ICC7 110 100 3, 4 Active ICC7A 150 140 3, 4 Standby ICC8 110 100 3, 4 Active ICC8A 150 140 3, 4 Standby ICC9 1 1 3, 4 mA 18 3, 4 5/39 ¡ Semiconductor MSM54V16272 AC Characteristics (1/3) Parameter Symbol -60 -70 Min. Max. Min. Max. Unit Note tRC 104 — 124 — ns tRWC 140 — 170 — ns tPC 30 — 35 — ns tPRWC 76 — 81 — ns tRAC — 60 — 70 ns 8, 14 Access Time from Column Address tAA — 30 — 35 ns 8, 14 Access Time from CAS tCAC — 15 — 20 ns 8, 15 Access Time from CAS Precharge tCPA — 35 — 40 ns 8, 15 Output Buffer Turn-off Delay tOFF 0 15 0 17 ns 10 7 Random Read or Write Cycle Time Read Modify Write Cycle Fast Page Mode Cycle Time Fast Page Mode Read Modify Write Cycle Time Access Time from RAS Transition Time (Rise and Fall) tT 2 35 2 35 ns RAS Precharge Time tRP 40 — 50 — ns RAS Pulse Width tRAS 60 10k 70 10k ns RAS Pulse Width (Fast Page Mode Only) tRASP 60 100k 70 100k ns RAS Hold Time tRSH 15 — 20 — ns CAS Hold Time tCSH 45 — 55 — ns CAS Pulse Width tCAS 15 10k 15 10k ns RAS to CAS Delay Time tRCD 15 42 15 50 ns 14 RAS to Column Address Delay Time tRAD 12 30 12 35 ns 14 Column Address to RAS Lead Time tRAL 30 — 35 — ns CAS to RAS Precharge Time tCRP 5 — 10 — ns CAS Precharge Time (Fast Page Mode) tCP 10 — 10 — ns Row Address Set-up Time tASR 0 — 0 — ns Row Address Hold Time tRAH 10 — 10 — ns Column Address Set-up Time tASC 0 — 0 — ns Column Address Hold Time tCAH 10 — 10 — ns Column Address Hold Time referenced to RAS tAR 50 — 55 — ns Read Command Set-up Time tRCS 0 — 0 — ns Read Command Hold Time tRCH 0 — 0 — ns 11 Read Command Hold Time referenced to RAS tRRH 0 — 0 — ns 11 13 Write Command Set-up Time tWCS 0 — 0 — ns Write Command Hold Time tWCH 10 — 10 — ns Write Command Hold Time referenced to RAS tWCR 50 — 55 — ns Write Command Pulse Width tWP 10 — 10 — ns Write Command to RAS Lead Time tRWL 15 — 15 — ns Write Command to CAS Lead Time tCWL 15 — 15 — ns 6/39 ¡ Semiconductor MSM54V16272 AC Characteristics (2/3) Parameter Symbol -60 -70 Min. Max. Min. Max. Unit Note Data Set-up Time tDS 0 — 0 — ns 12 Data Hold Time tDH 10 — 12 — ns 12 Data Hold Time referenced to RAS tDHR 50 — 55 — ns RAS to WE Delay Time tRWD 80 — 90 — ns 13 Column Address to WE Delay Time tAWD 50 — 55 — ns 13 CAS to WE Delay Time tCWD 35 — 40 — ns 13 Data to CAS Delay Time tDZC 0 — 0 — ns Data to TRG Delay Time tDZO 0 — 0 — ns Access Time from TRG tOEA — 15 — 20 ns Output Buffer Turn-off Delay from TRG tOEZ 0 15 0 15 ns TRG Command Hold Time tOEH 10 — 10 — ns RAS Hold Time referenced to TRG tROH 10 — 15 — ns CAS Set-up Time for CAS before RAS Cycle tCSR 5 — 5 — ns CAS Hold Time for CAS before RAS Cycle tCHR 10 — 10 — ns RAS Precharge to CAS Active Time tRPC 0 — 0 — ns Refresh Period tREF — 8 — 8 ms WE Set-up Time tWSR 0 — 0 — ns WE Hold Time tRWH 10 — 10 — ns DSF Set-up Time referenced to RAS tFSR 0 — 0 — ns DSF Hold Time referenced to RAS (1) tRFH 10 — 10 — ns DSF Hold Time referenced to RAS (2) tFHR 50 — 55 — ns DSF Set-up Time referenced to CAS tFSC 0 — 0 — ns DSF Hold Time referenced to CAS tCFH 10 — 10 — ns Write Per Bit Mask Data Set-up Time tMS 0 — 0 — ns Write Per Bit Mask Data Hold Time tMH 10 — 10 — ns RAS Pulse Width (CAS before RAS Self-Refresh) tRASS 100 — 100 — ms RAS Precharge Time (CAS before RAS Self-Refresh) tRPS 120 — 140 — ns CAS Hold Time (CAS before RAS Self-Refresh) tCHS 0 — 0 — ns TRG High Set-up Time tTHS 0 — 0 — ns TRG High Hold Time tTHH 10 — 10 — ns TRG Low Set-up Time tTLS 0 — 0 — ns TRG Low Hold Time tTLH 10 10k 10 10k ns TRG Low Hold Time referenced to RAS tRTH 50 10k 60 10k ns TRG Low Hold Time referenced to Column Address tATH 20 — 25 — ns TRG Low Hold Time referenced to CAS tCTH 15 — 20 — ns 7/39 ¡ Semiconductor MSM54V16272 AC Characteristics (3/3) Parameter Symbol -60 -70 Min. Max. Min. Max. Unit Note TRG to RAS Precharge Time tTRP 40 — 50 — ns TRG Precharge Time tTP 20 — 20 — ns RAS to First SC Delay Time (Read Transfer) tRSD 60 — 70 — ns Column Address to First SC Delay Time tASD 30 — 35 — ns CAS to First SC Delay Time (Read Transfer) tCSD 20 — 20 — ns Last SC to TRG Lead Time tTSL 5 — 5 — ns TRG to First SC Delay Time (Read Transfer) tTSD 10 — 10 — ns Last SC to RAS Set-up Time (Serial Input) tSRS 20 — 25 — ns Serial Output Buffer Turn-off Delay from RAS tSDZ 10 30 10 40 ns SC Cycle Time tSCC 18 — 20 — ns SC Pulse Width (SC High Time) tSC 5 — 5 — ns SC Precharge Time (SC Low Time) tSCP 5 — 5 — ns Access Time from SC tSCA — 15 — 17 ns 9 Serial Output Hold Time from SC tSOH 3 — 5 — ns 19 Access Time from SE tSEA — 15 — 17 ns 9 SE Pulse Width tSE 10 — 10 — ns SE Precharge Time tSEP 10 — 10 — ns Serial Output Buffer Turn-off Delay from SE tSEZ 0 15 0 15 ns Split Transfer Set-up Time tSTS 20 — 25 — ns Split Transfer Hold Time tSTH 20 — 25 — ns SC-QSF Delay Time tSQD — 20 — 25 ns TRG-QSF Delay Time tTQD — 20 — 25 ns CAS-QSF Delay Time tCQD — 30 — 35 ns RAS-QSF Delay Time tRQD — 70 — 75 ns RAS to Serial Input Delay Time tSDD 30 — 40 — ns Serial Input Set-up Time tSDS 0 — 0 — ns Serial Input Hold Time tSDH 10 — 10 — ns Serial Input to SE Delay Time tSZE 0 — 0 — ns Serial Input to First SC Delay Time tSZS 0 — 0 — ns Serial Write Enable Set-up Time tSWS 0 — 0 — ns Serial Write Enable Hold Time tSWH 10 — 10 — ns Serial Write Disable Set-up Time tSWIS 0 — 0 — ns Serial Write Disable Hold Time tSWIH 10 — 10 — ns 10 10 8/39 ¡ Semiconductor Notes: MSM54V16272 1. Exposure beyond the "Absolute Maximum Ratings" may cause permanent damage to the device. 2. All voltages are referenced to VSS. 3. These parameters depend on the cycle rate. 4. These parameters depend on output loading. Specified values are obtained with the output open. 5. An initial pause of 200 ms is required after power up followed by any 8 RAS cycles (TRG = "high") and any 8 SC cycles before proper device operation is achieved. In the case of using an internal refresh counter, a minimum of 8 CAS before RAS cycles instead of 8 RAS cycles are required. 6. AC measurements assume tT = 5 ns. 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. RAM port outputs are measured with a load equivalent to 1 TTL load and 50 pF. DOUT reference levels : VOH/VOL = 2.0 V/0.8 V. 9. SAM port outputs are measured with a load equivalent to 1 TTL load and 30 pF. DOUT reference levels : VOH/VOL = 2.0 V/0.8 V. 10. tOFF (Max.), tOEZ (Max.), tSDZ (Max.) and tSEZ (Max.) define the time at which the outputs achieve the open circuit condition, and are not referenced to output voltage levels. This parameter is sampled and not 100% tested. 11. Either tRCH or tRRH must be satisfied for a read cycle. 12. These parameters are referenced to CAS leading edge of early write cycles, and to WE leading edge in TRG controlled write cycles and read modify write cycles. 13. tWCS, tRWD, tCWD 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 throughout the entire cycle; If tRWD ≥ tRWD (Min.), tCWD ≥ tCWD (Min.) and tAWD ≥ tAWD (Min.), the cycle is a read modify write cycle, and the data out will contain data read from the selected cell; If neither of the above sets of conditions are satisfied, the condition of the data out is indeterminate. 14. Operation within the tRCD (Max.) limit ensures 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 by tCAC. 15. 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, then access time is controlled by tAA. 16. Input levels at the AC testing are 3.0 V/0 V. 17. Address (A0 - A8) may be changed two times or less while RAS = VIL. 18. Address (A0 - A8) may be changed once or less while CAS = VIH and RAS = VIL. 19. This is guaranteed by design. (tSOH/tCOH = tSCA/tCAC - output transition time) This parameter is not 100% tested. 9/39 ¡ Semiconductor MSM54V16272 TIMING WAVEFORM Read Cycle tRC tRAS tRP RAS tCSH tCRP tRSH tCAS tRCD CASL tCSH tCRP tRSH tCAS tRCD CASU , , tAR tRAD tASR Address tRAL tASC tRAH Row tCAH Column tFHR tFSR tRFH tFSC tCFH DSF tRCS tRRH WE tRCH tCAC tOFF tAA Open DQ0 - 7 Valid Data tRAC Open DQ8 - 15 Valid Data tROH tTHS tTHH tOEA tOEZ TRG "H" or "L" 10/39 ¡ Semiconductor MSM54V16272 Fast Page Mode Read Cycle tRASP tRP ,,, RAS tCSH tCRP tPC tRCD tCAS tCP tRSH tCAS tCP tCAS CASL tCSH tCRP tPC tRCD CASU tCAS tCP tRSH tCAS tCP tCAS tAR tRAD tASR Address tRAL tRAH tASC Row tCAH tASC Column tCAH tASC Column tCAH Column tFHR tFSR tRFH tFSC tCFH tFSC tCFH tFSC tCFH DSF tRCS tRCS tRCH tRCH tRCS tRRH tRCH WE tCAC tCAC tAA tAA tOFF DQ0 - 7 tCAC Valid Data Open tRAC tAA tOFF Valid Data tCPA DQ8 - 15 Valid Data Open tTHS tTHH tOEA tOFF Valid Data tCPA Valid Data Valid Data tOEZ TRG "H" or "L" 11/39 ¡ Semiconductor MSM54V16272 Write Cycle Function Table RAS Falling Edge Code CAS Falling Edge A C D B E DSF WE DQ DSF DQ Function RWM 0 0 Write Mask 0 Valid Data BWM 0 0 Write Mask 1 Column Mask Masked Block Write FWM 1 0 Write Mask X X Masked Flash Write RW 0 1 X 0 Valid Data BW 0 1 X 1 Column Mask LCR 1 1 X 1 Color Data Masked Write Normal Write Block Write Load Color Register WRITE MASK DATA: "Low" = Mask, "High" = No Mask Column Mask Data Lower Byte Upper Byte DQ0 - 15 Column Mask Data DQ0 Column 0 (A0 = 0, A1 = 0, A2 = 0) DQ1 Column 1 (A0 = 1, A1 = 0, A2 = 0) DQ2 Column 2 (A0 = 0, A1 = 1, A2 = 0) DQ3 Column 3 (A0 = 1, A1 = 1, A2 = 0) Low : Mask DQ4 Column 4 (A0 = 0, A1 = 0, A2 = 1) High : No Mask DQ5 Column 5 (A0 = 1, A1 = 0, A2 = 1) DQ6 Column 6 (A0 = 0, A1 = 1, A2 = 1) DQ7 Column 7 (A0 = 1, A1 = 1, A2 = 1) DQ8 Column 0 (A0 = 0, A1 = 0, A2 = 0) DQ9 Column 1 (A0 = 1, A1 = 0, A2 = 0) DQ10 Column 2 (A0 = 0, A1 = 1, A2 = 0) DQ11 Column 3 (A0 = 1, A1 = 1, A2 = 0) Low : Mask DQ12 Column 4 (A0 = 0, A1 = 0, A2 = 1) High : No Mask DQ13 Column 5 (A0 = 1, A1 = 0, A2 = 1) DQ14 Column 6 (A0 = 0, A1 = 1, A2 = 1) DQ15 Column 7 (A0 = 1, A1 = 1, A2 = 1) 12/39 ¡ Semiconductor MSM54V16272 Early Write Cycle tRC tRAS tRP RAS tCSH tRSH tCAS , , ,, , , ,, tCRP tRCD CASL tCSH tCRP tRSH tCAS tRCD CASU tAR tRAD tRAH tASR Address tRAL tASC Row tCAH Column tFHR tRFH tFSR DSF tFSC A tCFH B tCWL WE tRWL tRWH tWSR tWP C tWCR tWCS tMH tMS DQ0 - 7 tDHR tDS D DQ8 - 15 D tTHS tDH E tMH tMS tWCH tDHR tDS tDH E tTHH TRG "H" or "L" 13/39 ¡ Semiconductor MSM54V16272 Late Write Cycle tRC tRAS tRP RAS tCSH tRSH , ,,, , ,,, tCRP tRCD tCAS CASL tCSH tCRP tRSH tCAS tRCD CASU tAR tRAD tASR Address tRAH tRAL tASC Row tCAH Column tFHR tFSR DSF tRFH tFSC A tCFH B tCWL tWSR WE tRWH tRWL tRCS tWP C tWCR tDHR tMS DQ0 - 7 tDS tMH D tDH E tDHR tMS DQ8 - 15 tMH D tTHS tDS tDH E tOEH TRG "H" or "L" 14/39 ¡ Semiconductor MSM54V16272 Read Modify Write Cycle tRWC tRAS tRP RAS tCSH tCRP tRSH tCAS tRCD , ,, , , ,, , CASL tCSH tCRP tRSH tRCD tCAS CASU tAR tRAD Address tRAL tRAH tASR tASC Row Column tAWD tFHR tRFH tFSR DSF tCAH tFSC A tCFH B tCWL tRWH tWSR WE tRCS tCWD tRWL tWP C tRWD tCAC tMH tMS DQ0 - 7 tRAC tDZC Valid Data D tMH tMS DQ8 - 15 tDS tDH E tDS Valid Data D tDH E tDZO tTHS tTHH tOEA tOEZ tOEH TRG "H" or "L" 15/39 ¡ Semiconductor MSM54V16272 Fast Page Mode Early Write Cycle tRASP tRP RAS tCSH tCRP tPC tCAS tRCD tCP tCAS tRSH tCP tCAS CASL tCSH tCRP tPC tCAS tRCD tCP tCAS tRSH tCP tCAS CASU , ,, , tAR tRAL tRAD tASR tRAH Address tASC Row tCAH tASC Column tCAH tASC Column tCAH Column tFHR tFSR DSF tRFH tFSC tCFH A tFSC B tCFH tFSC B tCWL tCFH B tCWL tCWL tWSR tRWH tWP WE tWP tWP C tMS DQ0 - 7 tMH tDS D tMS DQ8 - 15 tDS E tMH D tTHS tDH tDS tDS E tDH E tDH tDS E tDH E tDH tDS tDH E tTHH TRG "H" or "L" 16/39 ¡ Semiconductor MSM54V16272 Fast Page Mode Read Modify Write Cycle tRASP tRP RAS tCSH tCRP tPRWC tCAS tRCD tCP tRSH tCAS tCP tCAS CASL tCSH tCRP tPRWC tCAS tRCD CASU tCP tRSH tCAS tCP tCAS tAR tRAL tRAD , , , , tASR Address tRAH tASC tASC tCAH Row Column tASC tCAH Column tCAH Column tFHR tFSR DSF tRFH A B tWSR WE tFSC tFSC tCFH B tCWL tAWD tRWH tFSC tCFH tCFH B tCWL tAWD tCWL tAWD C tWP tWP tCWD tCWD tRCS tCAC DQ0 - 7 tMH tMS DQ8 - 15 tDH tDH tDH tAA tDS tDS Out In Out In Out In Out In Out In Out In tMH D tOEZ tTHS tCAC tAA tDS D tCWD tCAC tAA tMS tWP tTHH tOEA tOEZ tOEA tOEZ tOEA TRG "H" or "L" 17/39 ¡ Semiconductor MSM54V16272 RAS Only Refresh Cycle tRC tRAS tRP ,,,, , ,,, , RAS tCRP tRPC CASL/U tASR Address tRAH Row tFSR tRFH DSF WE Open DQ0 - 15 tTHS tTHH TRG "H" or "L" 18/39 ¡ Semiconductor MSM54V16272 CAS before RAS Refresh Cycle tRC tRP tRAS tRP ,,,, ,,,, , RAS tRPC CASL/U tCSR tCHR tRPC Inhibit Falling Transition Address DSF WE tOFF DQ0 - 15 Open TRG "H" or "L" 19/39 ¡ Semiconductor MSM54V16272 CAS before RAS Self-Refresh Cycle tRP tRASS RAS tRPS tRPC tRPC tCSR tCHS CASL/U tOFF Open DQ0 - 15 "H" or "L" Note: Address, DSF, WE, TRG = "H" or "L" 20/39 ¡ Semiconductor MSM54V16272 Hidden Refresh Cycle tRC tRAS tRP tRAS , , ,, , , , RAS tCRP tRCD CASL/U tAR tRAD tASR Address tRSH tRAH tCHR tRAL tASC Row tCAH Column tFHR tFSR tRFH tFSC tCFH DSF tRCS WE tRRH tCAC tOFF tAA Open DQ0 - 15 Valid Data tRAC tTHS tTHH tOEA tOEZ TRG "H" or "L" 21/39 ¡ Semiconductor MSM54V16272 Read Transfer 1 tRC tRAS tRP RAS tCSH tRSH tCAS , ,,, ,, tRCD CASL/U tAR tRAD Address tRAL tASC tRAH tASR Row tFSR tCAH SAM Start tRFH DSF tWSR tRWH WE tASD tCSD DQ0 - 15 tRSD Open tTRP tTLS tTLH tTP tSC tTSD tSCP TRG tSRS Note 2 SC tSIS SDQ0 - 15 tSCA tSZS tSIH tSCA tSOH Data Out Din tRQD QSF tSCC tSC tCQD Note 3 tTQD Note 3 "H" or "L" Note 1: SE = "L" Note 2: There must be no rising transitions Note 3: QSF = "L"-- Lower SAM (0 - 255) is active QSF = "H"-- Upper SAM (256 - 511) is active 22/39 ¡ Semiconductor MSM54V16272 Read Transfer 2 (Real Time Read Transfer) tRC tRAS tRP RAS tCSH tRSH tCAS , ,,, tRCD CASL/U tAR tRAD Address tASC tRAH tASR tRAL Row tFSR tCAH SAM Start tRFH DSF tWSR tRWH WE tCTH tATH DQ0 - 15 Open tTRP tTLS tTP tRTH TRG tSCC tSCP tTSL tSC tTSD SC tSCA tSOH tSCA tSOH SDQ0 - 15 Data Out Data Out Data Out Data Out tTQD QSF Note 2 Note 2 "H" or "L" Note 1: SE = "L" Note 2: QSF = "L"-- Lower SAM (0 - 255) is active QSF = "H"-- Upper SAM (256 - 511) is active 23/39 ¡ Semiconductor MSM54V16272 Split Read Transfer tRC tRAS tRP RAS tCSH tRSH , ,,, tRCD CASL/U tCAS tAR tRAD tASR Address tRAH tRAL tASC Row tFSR tCAH SAM Start Sj tRFH DSF tWSR tRWH WE tCTH tATH DQ0 - 15 Open tRTH tTLS tTLH TRG tSTS SC SDQ0 - 15 STOP i tSCA tSOH Data Out tSCC tSCP tSC Si tSCA tSOH Data Out Data Out STOP j-1 STOP j Data Out Data Out Note 2 Data Out tSQD tSQD QSF Sj Note 2 Note 2 "H" or "L" Note 1: SE = "L" Note 2: QSF = "L"-- Lower SAM (0 - 255) is active QSF = "H"-- Upper SAM (256 - 511) is active Note 3: Si is the SAM start address in before SRT Note 4: STOP i and STOP j are programmable stop addresses 24/39 ¡ Semiconductor MSM54V16272 Masked Write Transfer tRC tRAS tRP RAS tCSH tRSH tCAS , ,, , tRCD CASL/U tAR tRAD tASR Address tRAL tASC tRAH Row tFSR tCAH SAM Start tRFH DSF tWSR tRWH WE tMS DQ0 - 15 tCSD tMH Open Mask Data tRSD tTLS tTLH TRG tSRS tSCC tSC tSCP tSC Note 2 SC tSDZ tSDS tSOH SDQ0 - 15 Dout Dout tSDH tSDS Data In tSDD tSDH Data In tCQD tRQD QSF Note 3 Note 3 "H" or "L" Note 1: SE = "L" Note 2: There must be no rising transitions Note 3: QSF = "L"-- Lower SAM (0 - 255) is active QSF = "H"-- Upper SAM (256 - 511) is active 25/39 ¡ Semiconductor MSM54V16272 Masked Split Write Transfer tRC tRAS tRP RAS tCSH tRSH tCAS , ,,, tRCD CASL/U tAR tRAD tASR Address tRAL tASC tRAH Row tFSR tCAH SAM Start Sj tRFH DSF tWSR tRWH WE tMS DQ0 - 15 tCTH tATH tMH Mask Data tTLS Open tRTH tTLH TRG tSTS SC tSCC tSCP tSC STOP i Si tSDS SDQ0 - 15 Data In tSDH Data In STOP j-1 tSDS Note 2 Sj tSDH Data In Data In Data In Data In tSQD tSQD QSF STOP j Note 2 Note 2 "H" or "L" Note 1: SE = "L" Note 2: QSF = "L"-- Lower SAM (0 - 255) is active QSF = "H"-- Upper SAM (256 - 511) is active Note 3: Si is the SAM start address in before SWT Note 4: STOP i and STOP j are programmable stop addresses 26/39 ¡ Semiconductor MSM54V16272 Serial Read Cycle tSEP SE tSCC tSC SC tSCP tSCA tSEZ tSOH SDQ0 - 15 Data Out tSEA Data tSCA tSCA tSOH tSOH Data Data Out Data Out ,, Serial Write Cycle tSEP SE tSCC tSC SC tSWH Data In tSWIH tSWS tSCP tSDS SDQ0 - 15 tSWIS tSDH Data In tSZE tSDS tSDH Data In Data In "H" or "L" 27/39 ¡ Semiconductor MSM54V16272 PIN FUNCTIONS Address Input: A0 - A8 The 18 address bits decode 16 bits of the 4,194,304 locations in the MSM54V16272 memory array. The address bits are multiplexed to 9 address input pins (A0 - A8) as standard DRAM. 9 row address bits are latched at the falling edge of RAS. The following 9 column address bits are latched at the falling edge of CAS. Row Address Strobe: RAS RAS is a basic RAM control signal. The RAM port is in standby mode when the RAS level is "high". As the standard DRAM’s RAS signal function, RAS is the control input that latches the row address bits, and a random access cycle begins at the falling edge of RAS. In addition to the conventional RAS signal function, the level of the input signals CAS, TRG, WE and DSF at the falling edge of RAS, determines the MSM54V16272 operation mode. Column Address Strobe: CASL and CASU As the standard DRAM’s CAS signal function, CAS is the control input signal that latches the column address input, and the state of the special function input DSF to select in conjunction with the RAS control, either read/write operations or the special block write feature on the RAM port when the DSF is held "low" at the falling edge of RAS. CAS also acts as a RAM port output enable signal. Data Transfer/Output Enable: TRG TRG is also a control input signal having multiple functions. As the standard DRAM’s OE signal function, TRG is used as an output enable control when TRG is "high" at the falling edge of RAS. In addition to the conventional OE signal function, a data transfer operation is started between the RAM port and the SAM port when TRG is "low" at the falling edge of RAS. Write Per Bit/Write Enable: WE WE is control input signal having multiple functions. As the standard DRAM’s WE signal function, this is used to write data into the memory on the RAM port when WE is "high" at the falling edge of RAS. In addition to the conventional WE signal function, the WE determines the write-per-bit function, when WE is "low" at the falling edge of RAS during RAM port operations. The WE also determines the direction of data transfer between the RAM and SAM. When the WE is "high" at the falling edge of RAS, the data is transferred from RAM to SAM (read transfer). When the WE is "low" at the falling edge of RAS, the data is transferred SAM to RAM (write transfer). 28/39 ¡ Semiconductor MSM54V16272 Write Mask Data/Data Input and Output: DQ0 - DQ15 In conventional write-per bit mode, the DQ pins function as mask data at the falling edge of RAS. Data is written only to high DQ pins. Data on low DQ pins is masked and internal data is retained. After that, they function as input/output pins similar to a standard DRAM. Serial Clock: SC SC is a main serial cycle control input signal. All operations of the SAM port are synchronized with the serial clock SC. Data is shifted in or out of the SAM registers at the rising edge of SC. In a serial read cycle, the output data becomes valid on the SDQ pins after the maximum specified serial access time tSCA from the rising edge of SC. In a serial write cycle, data on SDQ pins at the rising edge of SC are fetched into the SAM register. Serial Enable: SE The SE is a serial access enable control and serial read/write control signal. In a serial read cycle, SE is used as an output control. In a serial write cycle, SE is used as a write enable control. When SE is "high", serial access is disabled. However, the serial address pointer location is still incremented when SC is clocked even when SE is "high". Special Function Input: DSF The DSF is latched at the falling edge of RAS and CAS. It allows for the selection of several RAM ports and transfer operating modes. In addition to the conventional multiport DRAM, the special functions consisting of flash write, block write, load/read color register, and split read/write transfer can be invoked. Special Function Output: QSF QSF is an output signal, which during split register mode indicates which half of the split SAM is being accessed. QSF "low" indicates that the lower split SAM (0 - 255) is being accessed. QSF "high" indicates that the upper SAM (256 - 511) is being accessed. QSF is enabled by SE. When SE is "high", QSF is in high impedance. Serial Input/Output: SDQ0 - SDQ15 Serial input/output mode is determined by the most recent read or write transfer cycle. When a read transfer cycle is performed, the SAM port is in the output mode. When a write or pseudo write transfer cycle is performed, the SAM port is switched from output mode to input mode. 29/39 ¡ Semiconductor MSM54V16272 OPERATION MODES Table-1 shows the function truth table for a listing of all available RAM ports, and transfer operations of the MSM54V16272. The RAM port and data transfer operations are determined by the state of CAS, TRG, WE and DSF at the falling edge of RAS, and by the level of DSF at the falling edge of CAS. Table-1. Function Truth Table RASØ Code CASØ Address W/IO CAS TRG WE DSF DSF RASØ CASØ RASØ CAS /WEØ Write Color Mask Register Function * * * — — CBR Refresh — * — — — RAS Only Refresh Row TAP WM1 * Yes — Masked Write Transfer * Row TAP WM1 * Yes — 0 * Row TAP * * — — Read Transfer 1 1 * Row TAP * * — — Split Read Transfer 1 0 0 0 Row Column WM1 Din,Dout Yes — 1 1 0 0 1 Row Yes Use Masked Block Write FWM 1 1 0 1 * Row Yes Use Masked Flash Write RW 1 1 1 0 0 Row Column No — BW 1 1 1 0 1 Row No Use LCR 1 1 1 1 1 Row — Load CBR 0 * * * — * ROR 1 1 * 0 — Row MWT 1 0 0 0 * MSWT 1 0 0 1 RT 1 0 1 SRT 1 0 RWM 1 BWM Column A3c - 8c * Column A3c - 8c * WM1 Column Select WM1 — * * * Din,Dout Column Select Color Data Masked Split Write Transfer Read/Write (Mask) Read/Write (No Mask) Block Write (No Mask) Load Color Register If the DSF is "high" at the falling edge of RAS, special functions such as split transfer, flash write, load color register can be invoked. If the DSF is "low" at the falling edge of RAS and "high" at the falling edge of CAS, the block write feature can be invoked. 30/39 ¡ Semiconductor MSM54V16272 RAM PORT OPERATION RAM Read Cycle: RAS falling edge --- TRG = CAS = "H", DSF = "L" CAS falling edge --- DSF = "L" Row address is entered at the falling edge of RAS and column address at the falling edge of CAS to the device as in conventional DRAM. When the WE is "high" and TRG is "low" while CAS is "low", the data outputs through DQ pins. RAM Write Cycle: RAS falling edge --- TRG = CAS = "H", DSF = "L" CAS falling edge --- DSF = "L" 1) Write cycle with no mask: RAS falling edge -- WE = "H" If WE is set "low" at the falling edge of CAS after RAS goes "low", a write cycle is excuted. If WE is set "low" before the CAS falling edge, this cycle becomes an early write cycle, and all DQ pins attain high impedance. If WE is "low" when CAS goes "low", the write affects only those corresponding 8 bits with the latched data. If WE is set "low" after the CAS falling edge, this cycle becomes a late write cycle, and all 16 data are latched on the falling edge of WE. Byte write occurs if either CASL or CASU falls during the cycle. DQ pins don't achieve high impedance in this cycle, so data should be entered with TRG in "high". 2) Write cycle with mask: RAS falling edge -- WE = "L" If WE is set "low" at the falling edge of RAS, the mask write mode can be invoked. Mask data is loaded and used. The mask data on DQ0 - DQ15 is latched into the write mask register at the falling edge of RAS. When the mask data is low, writing is inhibited into the RAM and the mask data is high, data is written into the RAM. This mask data is in effect during the RAS cycle. In page mode cycle the mask data is retained during page access. 31/39 ¡ Semiconductor Load/Read Color Register: MSM54V16272 RAS falling edge --- CAS = TRG = WE = DSF = "H" CAS falling edge --- DSF = "H" The MSM54V16272 is provided with an on-chip 16-bit color register for use during the flash write or block write operation. Each bit of the color register corresponds to one of the DRAM I/O blocks. The data presented on the DQi lines is subsequently latched into the color register at the falling edge of either CAS or WE whichever occurs later. The read color register cycle is activated by holding WE "high" at the falling edge of CAS, and throughout the remainder of the cycle. The data in the color register becomes valid on the DQi lines after the specified access times from RAS and TRG are satisfied. During the load/read color register cycle, the memory cells on the row address latched at the falling edge of RAS are refreshed. Flash Write: RAS falling edge --- CAS = TRG = DSF = "H", WE = "L" Flash write allows for the data in the color register to be written into all the memory locations of a selected row. Each bit of the color register corresponds to one of the DRAM I/O blocks. The flash write operation can be selectively controlled on an I/O basis in the same manner as the write per bit operation. The mask data is the same as that of a RAM write cycle. 32/39 ¡ Semiconductor MSM54V16272 Block Write: RAS falling edge --- CAS = TRG = "H", DSF = "L" CAS falling edge --- DSF = "H" Block write allows for the data in the color register to be written into 8 consecutive column address locations, starting from a selected column address in a selected row. The block write operation can be selectively controlled on an I/O basis, and a column mask capability is also available. This function is implemented as lower byte and upper byte. During a block write cycle, the 3 least significant column address locations (A0C, A1C and A2C) are internally controlled, and only the 6 most significant column addresses (A3C - A8C) are latched at the falling edge of CAS. 1) No mask block write: WE "high" at the falling edge of RAS The data on 16 DQ pins is cleared by the data of the color register. 2) Masked block write: WE "low" at the falling edge of RAS The mask data is the same as that of a RAM write cycle. (new mask and persistent mask) Bit 0 Bit 15 Color Register 11001110 01110011 I/O Mask 11111010 01101011 Column Mask 10010011 00111100 Lower Byte Upper Byte Column 7 1 1 0 0 1 * 1 * * * * * * * * * Column 6 1 1 0 0 1 * 1 * * * * * * * * * Column 5 * * * * * * * * * 1 1 * 0 * 1 1 Column 4 * * * * * * * * * 1 1 * 0 * 1 1 Column 3 1 1 0 0 1 * 1 * * 1 1 * 0 * 1 1 Column 2 * * * * * * * * * 1 1 * 0 * 1 1 Column 1 * * * * * * * * * * * * * * * * Column 0 1 1 0 0 1 * 1 * * * * * * * * * DQ1 DQ2 DQ3 DQ4 DQ5 DQ6 DQ7 DQ8 DQ9 DQ10 DQ11 DQ12 DQ13 DQ14 DQ15 8 Column ¥ 8 DQ (Upper Byte) DQ0 8 Column ¥ 8 DQ (Lower Byte) Note : Location "*" can not be loaded. Example of Block Write 33/39 ¡ Semiconductor MSM54V16272 SAM PORT OPERATION Single Register Mode High speed serial read or write operations can be performed through the SAM port independent of the RAM port operation, except during read/write transfer cycles. The preceding transfer operation determines the direction of data flow through the SAM port. If the preceding transfer is a read transfer, the SAM port is in the output mode. If the preceding transfer is write transfer, the SAM port is in the input mode. Serial data can be read out of the SAM after a read transfer has been performed. The data is shifted out of the SAM starting at any of the 512 bits locations. The TAP location corresponds to the column address selected at the falling edge of CAS during the read or write transfer cycle. The SAM registers are configured as a circular data register. The data is shifted out sequentially. It starts from the selected TAP location at the most significant bit (511), then wraps around to the least significant bit (0). Split Register Mode In split register mode data can be shifted into or out of one half of the SAM, while a split read or split write transfer is being performed on the other half of the SAM. Conventional (non split) read, or write transfer cycle must precede any split read or split write transfers. The split read and write transfers will not change the SAM port mode set by the preceding conventional transfer operation. In the split register mode, serial data can be shifted in or out of one of the split SAM registers, starting from any at the 256 TAP locations, excluding the last address of each split SAM the data is shifted in or out sequentially starting from the selected TAP location at the most significant bit (255 or 511) of the first split SAM, and then the SAM pointer moves to the TAP location selected for the second split SAM to shift data in or out sequentially, starts from this TAP location at the most significant bit (511 or 255), and finally wraps around to the least significant bit. TAP 0 1 2 TAP 255 256 257 511 34/39 ¡ Semiconductor MSM54V16272 DATA TRANSFER OPERATIONS Upper SAM 256 ¥ 16 256 ¥ 256 ¥ 16 Memory Array Lower SAM 256 ¥ 16 Upper SAM 256 ¥ 16 256 ¥ 256 ¥ 16 Memory Array Serial Decoder 256 ¥ 256 ¥ 16 Memory Array Lower SAM 256 ¥ 16 The MSM54V16272 features two types of bidirectional data transfer capability between RAM and SAM. 1) Conventional (non split) transfer: 512 words by 16 bits of data can be loaded from RAM to SAM (Read transfer), or from SAM to RAM (Write transfer). 2) Split transfer: 256 words by 16 bits of data can be loaded from the lower/upper half of the RAM to the lower/upper half of the SAM (Split read transfer), or from the lower/upper half of SAM to the lower/upper half of RAM (Split write transfer). The conventional transfer and split transfer modes are controlled by the DSF input signal. Data transfer is invoked by holding the TRG signal "low" at the falling edge of RAS. The MSM54V16272 supports 4 types of transfer operations: Read transfer, Split read transfer, Write transfer and Split write transfer as shown in the truth table. The type of transfer operation is determined by the state of CAS, WE and DSF latched at the falling edge of RAS. During conventional transfer operations, the SAM port is switched from input to output mode (Read transfer), or output to input mode (Write transfer). It remains unchanged during split transfer operation (Split read transfer or Split write transfer). Both RAM and SAM are divided by the most significant row address (AX8), as shown in Figure 1. Therefore, no data transfer between AX8 = 0 side RAM and AX8 = 1 side RAM can be provided through the SAM. Care must be taken if the split read transfer on AX8 = 1 side (or AX8 = 0 side) is provided after the read transfer or the split read transfer, is provided on AX8 = 0 side (or AX8 = 1 side). 256 ¥ 256 ¥ 16 Memory Array AX8 = 0 AX8 = 1 SAM I/O Buffer SDQ0 - 15 Figure 1. RAM and SAM Configuration 35/39 ¡ Semiconductor MSM54V16272 Read Transfer: RAS falling edge --- CAS = WE = "H", TRG = DSF = "L" Read transfer consists of loading a selected row of data from the RAM into the SAM register. A read transfer is invoked by holding CAS "high", TRG "low", WE "high", and DSF "low" at the falling edge of RAS. The row address selected at the falling edge of RAS determines the RAM row to be transferred into the SAM. The transfer cycle is completed at the rising edge of TRG. When the transfer is completed, the SAM port is set into the output mode. In a read/real time read transfer cycle, the transfer of a new row of data is completed at the rising edge of TRG, and this data becomes valid on the SDQ lines after the specified access time tSCA from the rising edge of the subsequent SC cycles. The start address of the serial pointer of the SAM is determined by the column address selected at the falling edge of CAS. In a read transfer cycle (which is preceded by a write transfer cycle), SC clock must be held at a constant VIL or VIH after the SC high time has been satisfied. A rising edge of the SC clock must not occur until after the specified delay tTSD from the rising edge of TRG. In a real time read transfer cycle (which is preceded by another read transfer cycle), the previous row data appears on the SQD lines until the TRG signal goes "high", and the serial access time tSCA for the following serial clock is satisfied. This feature allows for the first bit of the new row of data to appear on the serial output as soon as the last bit of the previous row has been strobed without any timing loss. To make this continuous data flow possible, the rising edge of TRG must be synchronized with RAS, CAS, and the subsequent rising edge of SC (tRTH, tCTH and tTSL/tTSD must be satisfied). Masked Write Transfer: RAS falling edge --- CAS = "H", TRG = DSF = "L" WE = "L" Write transfer cycle consists of loading the content of the SAM register into a selected row of the RAM. This write transfer operation, which is the same as a mask write operation in RAM, can be selectively controlled for 16 DQis by inputing the mask data from DQ0 - DQ15 at the falling edge of RAS. If the SAM data to be transferred must first be loaded through the SAM, a Masked write transfer operation (all DQ pins "low" at falling edge of RAS) must precede the write transfer cycles. A masked write transfer is invoked by holding CAS "high", TRG "low", WE "low", and DSF "low" at the falling edge of RAS. The row address selected at the falling edge of RAS determines the RAM row address into which the data will be transferred. The column address selected at the falling edge of CAS determines the start address of the serial pointer of the SAM. After the write transfer is completed, the SDQ lines are set in the input mode so that serial data synchronized with the SC clock can be loaded. When consecutive write transfer operations are performed, new data must not be written into the serial register until the RAS cycle of the preceding write transfer is completed. Consequently, the SC clock must be held at a constant VIL or VIH during the RAS cycle. A rising edge of the SC clock is only allowed after the specified delay tCSD from the falling edge of the CAS, at which time a new row of data can be written in the serial register. Data transferred to SAM by read transfer cycle or split read transfer cycle can be written to the other address of RAM by write transfer cycle. However, the address to write data must be the same as that of the read transfer cycle (row address AX8). 36/39 ¡ Semiconductor MSM54V16272 Split Data Transfer and QSF The MSM54V16272 features a bidirectional split data transfer capability between the RAM and SAM. During split data transfer operation, the serial register is split into two halves which can be controlled independently. Split read or split write transfer operation can be performed to or from one half of the serial register, while serial data can be shifted into or out of the other half of the serial register. The most significant column address location (A8C) is controlled internally to determine which half of the serial register will be reloaded from the RAM. QSF is an output which indicates which half of the serial register is in an active state. QSF changes state when the last SC clock is applied to active split SAM. Split Read Transfer: RAS falling edge --- CAS = WE = DSF = "H", TRG = "L" Split read transfer consists of loading 256 words by 16 bits of data from a selected row of the split RAM into the corresponding non-active split SAM register. Serial data can be shifted out from the other half of the split SAM register simultaneously. During split read transfer operation, the RAM port input clocks do not have to be synchronized with the serial clock SC, thus eliminating timing restrictions as in the case of real time read transfers. A split read transfer can be performed after a delay of tSTS from the change of state of the QSF output is satisfied. Conventional (non-split) read transfer operation must precede split read transfer cycles. Masked Split Write Transfer: RAS falling edge --- CAS = DSF = "H", TRG = "L" WE = "L" Split write transfer consists of loading 256 words by 16 bits of data from the non-active split SAM register into a selected row of the corresponding split RAM. Serial data can be shifted into the other half of the split SAM register simultaneously. During split write transfer operation, the RAM port input clocks do not have to be synchronized with the serial clock SC, thus allowing for real time transfer. This write transfer operation, which is the same as a mask write operation in RAM, can be selectively controlled for 16 DQis by inputing the mask data from DQ0 - DQ15 at the falling edge of RAS. A split write transfer can be performed after a delay of tSTS from the change of state of the QSF output is satisfied. A masked write transfer operation must precede split write transfer. The purpose is to switch the SAM port from output mode to input mode, and to set the initial TAP location prior to split write transfer operations. POWER UP Power must be applied to the RAS and TRG input signals to pull them "high" before, or at the same time as, the VCC supply is turned on. After power-up, a pause of 200 ms minimum is required with RAS and TRG held "high". After the pause, a minimum of 8 RAS and 8 SC dummy cycles must be performed to stabilize the internal circuitry, before valid read, write or transfer operations can begin. During the initialization period, the TRG signal must be held "high". If the internal refresh counter is used, a minimum 8 CAS before RAS cycles are required instead of 8 RAS cycles. (NOTE) INITIAL STATE AFTER POWER UP The initial state can not be guaranteed for various power up conditions and input signal levels. Therefore, it is recommended that the initial state be set after the initialization of the device is performed and before valid operations begin. 37/39 ¡ Semiconductor MSM54V16272 PACKAGE DIMENSIONS (Unit : mm) SSOP64-P-525-0.80-K Mirror finish Package material Lead frame material Pin treatment Solder plate thickness Package weight (g) Epoxy resin 42 alloy Solder plating 5 mm or more 1.34 TYP. Notes for Mounting the Surface Mount Type Package The SOP, QFP, TSOP, SOJ, QFJ (PLCC), SHP and BGA are surface mount type packages, which are very susceptible to heat in reflow mounting and humidity absorbed in storage. Therefore, before you perform reflow mounting, contact Oki’s responsible sales person for the product name, package name, pin number, package code and desired mounting conditions (reflow method, temperature and times). 38/39 ¡ Semiconductor MSM54V16272 (Unit : mm) TSOPII70/64-P-400-0.65-K Mirror finish Package material Lead frame material Pin treatment Solder plate thickness Package weight (g) Epoxy resin 42 alloy Solder plating 5 mm or more 0.59 TYP. Notes for Mounting the Surface Mount Type Package The SOP, QFP, TSOP, SOJ, QFJ (PLCC), SHP and BGA are surface mount type packages, which are very susceptible to heat in reflow mounting and humidity absorbed in storage. Therefore, before you perform reflow mounting, contact Oki’s responsible sales person for the product name, package name, pin number, package code and desired mounting conditions (reflow method, temperature and times). 39/39