Scsi Control Three SCNTL3 Register, Bits 64 SCF20 | LSI 53C875A

2.2.15.2SCSI Control Three (SCNTL3) Register, Bits [6:4] (SCF[2:0])

The SCF[2:0] bits select the factor by which the frequency of SCLK is divided before being presented to the synchronous SCSI control logic. The output from this divider controls the rate at which data can be received; this rate must not exceed 160 MHz. The receive rate of synchronous SCSI data is one-fourth of the SCF divider output. For example, if SCLK is 80 MHz and the SCF value is set to divide by one, then the maximum rate at which data can be received is 20 MHz (80/(1*4) = 20).

2.2.15.3SCSI Control Three (SCNTL3) Register, Bits [2:0] (CCF[2:0])

The CCF[2:0] bits select the factor by which the frequency of SCLK is divided before being presented to the asynchronous SCSI core logic. This divider must be set according to the input clock frequency in the table.

2.2.15.4SCSI Transfer (SXFER) Register, Bits [7:5] (TP[2:0])

The TP[2:0] divider bits determine the SCSI synchronous transfer period when sending synchronous SCSI data in either the initiator or target mode. This value further divides the output from the SCF divider.

2.2.15.5 Ultra SCSI Synchronous Data Transfers

Ultra SCSI is an extension of the current Fast SCSI-2 synchronous transfer specifications. It allows synchronous transfer periods to be negotiated down as low as 50 ns, which is half the 100 ns period allowed under Fast SCSI-2. This allows a maximum transfer rate of 40 Mbytes/s on a 16-bit SCSI bus. The LSI53C875A has a SCSI clock quadrupler that must be enabled for the chip to perform Ultra SCSI transfers with a 20 or 40 MHz oscillator. In addition, the following bit values affect the chip’s ability to support Ultra SCSI synchronous transfer rates:

•Clock Conversion Factor bits, SCSI Control Three (SCNTL3) register bits [2:0] and Synchronous Clock Conversion Factor bits, SCNTL3 register bits [6:4]. These fields support a value of 111 (binary), allowing the 160 MHz SCLK frequency to be divided by 8 for the asynchronous logic.

2-36	Functional Description

Image 58

LSI 53C875A Scsi Control Three SCNTL3 Register, Bits 64 SCF20, Scsi Control Three SCNTL3 Register, Bits 20 CCF20

Contents

Technical Manual C e m b e r 2 0 0 Trademark Acknowledgment Audience Organization Ansi Revision Record PCI Special Interest GroupConventions Used in This Manual Revision Date Remarks ViPreface Contents Chapter Signal Descriptions Chapter Registers Figures Contents Tables IRDY/, TRDY/, DEVSEL/, STOP/, PERR/, PAR XivContents Chapter General Description Typical LSI53C875A System Application New Features in the LSI53C875A Benefits of Ultra Scsi TolerANT Technology LSI53C875A Benefits Summary Scsi Performance Integration PCI PerformanceEase of Use Flexibility Scripts RAM Reliability Testability Chapter Functional Description PCI Functional Description PCI Addressing PCI Bus Commands and Functions Supported Configuration Space Special Cycle Command PCI Bus Commands and Encoding Types for the LSI53C875AInterrupt Acknowledge Command CBE30 Command Type Supported as Master Supported as Slave Reserved Command 2.3 I/O Read Command2.4 I/O Write Command Memory Read Command Dual Address Cycle DAC Command Memory Read Multiple CommandMemory Read Line Command PCI Functional Description Memory Write and Invalidate Command PCI Cache Mode Enabling Cache Mode Issuing Cache Commands Memory Read Caching Memory Write Caching PCI Cache Mode Alignment Host Memory Examples Read Example Write Example Write Example Scsi Functional Description Memory-to-Memory Moves Phase Mismatch Handling in Scripts Scripts Processor Internal Scripts RAM 3 64-Bit Addressing in Scripts Hardware Control of Scsi Activity LED Using the Scsi Clock Quadrupler Designing an Ultra Scsi System Prefetching Scripts Instructions Opcode Fetch Burst Capability Load and Store Instructions Jtag Boundary Scan Testing Scsi Loopback Mode Parity Options Bits Used for Parity Control and Generation Bit Name Location Description Scsi Parity Errors and Interrupts Scsi Parity Control DMA Fifo Parity Checking/Generation DMA Fifo Sections Data Paths LSI53C875A Host Interface Scsi Data Paths Asynchronous Scsi Send Synchronous Scsi Send Asynchronous Scsi Receive Synchronous Scsi Receive Scsi Bus Interface Scsi Termination Select/Reselect During Selection/Reselection Regulated Termination for Ultra Scsi Synchronous Operation Determining the Data Transfer Rate Determining the Synchronous Transfer Rate Scsi Transfer Sxfer Register, Bits 75 TP20 Scsi Control Three SCNTL3 Register, Bits 64 SCF20Scsi Control Three SCNTL3 Register, Bits 20 CCF20 Ultra Scsi Synchronous Data Transfers Polling and Hardware Interrupts Interrupt HandlingRegisters Functional Description Fatal vs. Nonfatal Interrupts Masking Stacked Interrupts Halting in an Orderly Fashion Sample Interrupt Service Routine Read Interrupt Status Zero ISTAT0 Chained Block Moves Block Move and Chained Block Move Instructions Wide Scsi Send Bit Swide Register Wide Scsi Receive BitSodl Register Chained Block Move Scripts Instruction Parallel ROM Interface Parallel ROM Support MAD31 Available Memory Space Default Download Mode Serial Eeprom Interface Mode a Serial Eeprom Data Format Power ManagementNo Download Mode Byte Name Description Power States Power State D0Power State D1 Configuration Register Bits Power State D2 Power State D3 Functional Description Chapter Signal Descriptions LSI53C875A Functional Signal Grouping LSI53C875A Functional Signal Grouping Signal Name Pull-up Current Conditions for Pull-up Signal DescriptionsInternal Pull-ups on LSI53C875A Signals LSI53C875A Internal Pull-ups System Signals PCI Bus Interface SignalsSystem Signals Type Strength Description Address and Data Signals Address and Data SignalsBus Command and Byte Enables are Interface Control Signals Interface Control SignalsInitialization Device Select is used as a chip select Arbitration Signals Arbitration SignalsError Reporting Signals Error Reporting Signals Scsi Bus Interface Signal Scsi Bus Interface SignalsInterrupt Signal Interrupt Signal Scsi Signals Scsi SignalsScsi Control Signals 10 Scsi Control Signals Scsi General Purpose I/O pin. Optionally Gpio Signals11 Gpio Signals Scsi General Purpose I/O pin. This pin ROM Flash and Memory Interface Signals 12 ROM Flash and Memory Interface Signals 13 Test Interface Signals Test Interface SignalsMemory Address/Data Bus. This bus is used Power and Ground Signals 14 Power and Ground Signals 15 Decode of MAD Pins MAD Bus Programming MAD Bus Programming Signal Descriptions PCI Configuration Registers Chapter Registers Vendor ID Read Only RegistersVIDVendor ID150 Device ID Read Only Command Read/WriteEnable Parity Error Response DIDDevice ID150 EMS WIEEBM EIS RMA DPESSE RTA Revision ID Rev ID Read Only RegisterDPR RIDRevision ID70 Registers 0x09-0x0B Register 0x0C Register 0x0E Register 0x0DRegister 0x0F BAR0 BAR1 Registers 0x28-0x2B Registers 0x18-0x1BRegisters 0x1C-0x27 Registers 0x2C-0x2D SID Registers 0x2E-0x2FSubsystem ID Read Only Subsystem ID 150 Erba Expansion ROM Base Address Read/WriteExpansion ROM Base Address 310 Capabilities Pointer Read Only CPCapabilities Pointer70 Registers 0x35-0x3BRegister 0x3C Interrupt Line Read/Write ILInterrupt Line70 Register 0x3F Register 0x3DRegister 0x3E MGMINGNT70 Pmes DSI D2SD1S APS PEN DsclDslt Bridge Support Extensions Pmcsrbse Read Only Data Read Only Scsi RegistersDATAData70 Scsi Register Address Map Scsi Control Zero SCNTL0 Read/Write ARB10 Arbitration Mode Bits 1Arbitration Mode Simple Arbitration Full Arbitration, Selection/Reselection Start Start Sequence5 EPC WatnAAP ADB EXCDHP Aesp CONRST Iarb SSTStart Scsi Transfer0 SDU Chained ModeScsi Control Two SCNTL2 Read/Write Scsi Disconnect Unexpected WSS SlpmdSlphben VUE0 Scsi Control Three SCNTL3 Read/Write Ultra Scsi EnableWSRWide Scsi Receive0 USE EWS Enable Wide ScsiSCF20 Synchronous Clock Conversion Factor CCF20 Clock Conversion Factor SRE RREENC Scsi Transfer Sxfer Read/Write TP20 Scsi Synchronous Transfer Period Transfer Rate Synch CLK MHzBits Period ns Mbytes/s MO40 Max Scsi Synchronous Offset Maximum Synchronous Offset Synchronous Offset General Purpose GPREG0 Read/Write Scsi Destination ID Sdid Read/WriteEncoded Destination Scsi ID Gpio Scsi First Byte Received Sfbr Read/Write Sfbr Scsi First Byte Received70 BSY REQACK SEL VAL Register 0x0ARegister 0x0B Enid SBSY/ Status SREQ/ StatusSACK/ Status SSEL/ Status SSI MdpeAbrt SIR Scsi Registers ORF ILFOLF LOA AIPWOA Bytes or Words Scsi Synchronous Data Fifo Word CountSSTAT2 bit SDP0L ORF1 ILF1OLF1 SDP1 SPL1Ldsc DSA Interrupt Status Zero ISTAT0 Read/Write Srst Software Reset6Abort Operation SEM Signal ProcessSigp Semaphore Sipscsi Interrupt Pending1 Dipdma Interrupt Pending0 Srun FlshSyncirqd Mailbox One MBOX1 Read/Write Mailbox Zero MBOX0 Read/WriteMBOX0 Mailbox Zero70 MBOX1 Mailbox One70 Chip Test One CTEST1 Read Only Chip Test Zero CTEST0 Read/WriteFMTByte Empty in DMA FIFO70 FFLByte Full in DMA FIFO70 Ddir Register 0x1ACIO Dreq TeopDack FLF Register 0x1BCLF Temp Registers 0x1C-0x1FDMA Fifo Dfifo 58Registers ZSD BdisFBL3 Srtm Adck FBL20 Fifo Byte ControlChip Test Five CTEST5 Read/Write Clock Address Incrementor Masr BbckDFS BL2 Dfdma FIFO70 DBC DMA Command Dcmd Read/Write Dcmd DMA Command70 Dnad Registers 0x2C-0x2FDSP Scratch Register a Scratcha Read/Write DMA Scripts Pointer Save Dsps Read/WriteDsps DMA Scripts Pointer Save310 Scratcha Scratch Register a 310 DMA Mode Dmode Read/Write BL10 Burst Length ERLEnable Read Line3 Source I/O Memory EnableDestination I/O Memory Enable Siom Ermp Enable Read MultipleBurst Opcode Fetch Enable BOF Scripts Interrupt Instruction Received Reserved DMA Interrupt Enable Dien Read/WriteMaster Data Parity Error Bus Fault Illegal Instruction Detected Clse Register 0x3ARegister 0x3B PFF SSM Single Step ModeIrqmirq Mode3 Irqd IRQ DisableSTDStart DMA Operation2 COMLSI53C700 Compatibility0 0x40 Registers 0x3C-0x3FAdder SGE CMPRSL UDC STO GEN Initiator Mode Phase Mismatch Target Mode SATN/ Active HTHHandshake-to-Handshake Timer Expired0Scsi Interrupt Status Zero SIST0 Read Only This bit is set when an arbitration only or full arbitration PAR Parity ErrorScsi RST/ Received Scsi Interrupt Status One SIST1 Read Only Scsi Longitudinal Parity Slpar Read/Write Handshake-to-Handshake Timer ExpiredHTH Slpar Scsi Longitudinal Parity70 Data Bytes Running Slpar Swide Scsi Wide Residue70 Memory Access Control Macntl Read/WriteScsi Wide Residue Swide Read/Write TYP Pscpt DWRDRD Scpts Scripts Scsi Timer Zero STIME0 Read/Write Gpio EnableGpiogpio Enable10 HTH30 Handshake-to-HandshakeTimer Period SEL30 Selection Time-Out30 Gensf HthbaHthsf Register 0x4A Register 0x4B SLT Register 0x4CSsaid ART ISO Register 0x4DSclk QEN SCE Register 0x4EQsel ROF EXT SZMAWS LOW Register 0x4F STR S16 Bit System Disable Single Initiator ResponseTimer Test Mode TTM Scsi Input Data Latch Sidl Read Only STWSidlscsi Input Data Latch150 Register 0x53 Lock Enpmj Enable Phase Mismatch JumpChip Control 0 CCNTL0 Read/Write Pmjctl Jump Control6 Disfc EnndjDils Ddac Zmode64TIMOD EN64DBMV Enable 64-Bit Direct BmovEN64TIBMV Scsi Bus Data Lines Sbdl Read Only Registers 0x5C-0x5F 64-Bit Scripts SelectorsRegister 0x5A-0x5B Registers 0x60-0x9F Mmrs Registers 0xA0-0xA3Memory Move Read Selector Mmrs Read/Write Memory Move Read Selector Mmrs Mmws Registers 0xA4-0xA7Registers 0xA8-0xAB SFS DRS Registers 0xAC-0xAFRegisters 0xB0-0xB3 Sbms Registers 0xB8-0xBB Phase Mismatch Jump RegistersRegisters 0xB4-0xB7 Registers 0xBC-0xBF PMJAD1 Registers 0xC0-0xC3Registers 0xC4-0xC7 PMJAD2 Registers 0xCC-0xCF Registers 0xC8-0xCBRBC ESA Registers 0xD0-0xD3Entry Storage Address ESA Read/Write Entry Storage Address 310 Registers 0xD8-0xDA Registers 0xD4-0xD7SBC Registers 0xE0-0xFF Register 0xDBRegisters 0xDC-0xDF Csbc Low Level Register Interface Mode Scsi Scripts High Level Scsi Scripts Mode Scripts Instructions Sample OperationInstruction Description Scsi Scripts Instruction Set Scripts Overview Block Move Instruction First Dword TIA Direct AddressingTable Indirect Bit Addressing Command Not Used Don’t Care OPCOpCode27 Target ModeOPC Instruction Defined Initiator Mode SCSIP20 Scsi Phase2624 Scsi Phase Scsi Information Transfer PhaseTC230 Transfer Counter230 Second Dword Target Mode Initiator ModeI/O Instruction Start Address 310 Reselect Instruction IT10 Instruction Type I/O Instruction 3130OPC20 OpCode 2927 Instruction Defined Set Instruction Disconnect InstructionWait Select Instruction Clear Instruction Select Instruction Wait Disconnect Instruction Wait Reselect Instruction Relative Addressing Mode TITable Indirect Mode25 Relative DirectTable Indirect Bit Command Table Offset Absolute Jump Offset Table Relative Set/Clear Sack Reserved Set/Clear Satn O20 Operator 2624 Read/Write InstructionsIT10 Instruction Type Read/Write Instruction 3130 Use data8/SFBR Read-Modify-Write Cycles A60 Register Address A60 2216 Move To/From Sfbr Cycles Read/Write Instructions Transfer Control Instructions Transfer Control Instructions IT10 Instruction Type Transfer Control 3130Jump Instruction Call Instruction Return Instruction Interrupt Instruction Interrupt-on-the-Fly Instruction Jump/Call an Absolute Address Scsi Phase ComparisonsRARelative Addressing Mode23 Jump/Call a Relative Address JMP Bit 2 is assertedJump If True/False Compare Data Compare PhaseWait for Valid Phase WVP Data Compare Value Memory Move InstructionsDCV Jump Address 310 Reserved 2825 IT20 Instruction Type Memory Move 3129No Flush Read/Write System Memory from Scripts Dsps Register 310 Temp Register 310 Load and Store InstructionsThird Dword Bit A1 Bit A0 Number of Bytes Allowed to Load and Store Reserved 2726 No Flush Store instruction only IT20 Instruction Type 3129DSA Relative Bit Source Destination This bit has no effect unless the Prefetch Enable bit DMA Control Dcntl register is set Scsi Scripts Instruction Set Chapter Electrical Specifications DC Characteristics Operating Conditions1 Symbol Parameter Min Max Unit Test ConditionsAbsolute Maximum Stress Ratings1 Input Capacitance Bidirectional Signals-MAD70, MAS/10, MCE/, MOE/, MWE Bidirectional Signals-GPIO0FETCH/, GPIO1MASTER/, GPIO24 Output Signal-TDO Output Signals-IRQ/, MAC/TESTOUT, REQ TolerANT Technology Electrical CharacteristicsOutput Signal-SERR Symbol Parameter Min1 Max Unit Test Conditions Pqfp Rise and Fall Time Test Condition Input Current as a Function of Input Voltage Symbol Parameter Min Max Unit AC Characteristics12 External Clock1 Reset Input Interrupt Output PCI and External Memory Interface Timing Diagrams Electrical Specifications PCI Configuration Register Read 15 PCI Configuration Register ReadTarget Timing 16 PCI Configuration Register Write 10 PCI Configuration Register Write 17 32-Bit Operating Register/SCRIPTS RAM Read 11 32-Bit Operating Register/SCRIPTS RAM Read 18 64-Bit Address Operating Register/SCRIPTS RAM Read 12 64-Bit Address Operating Register/SCRIPTS RAM Read 19 32-Bit Operating Register/SCRIPTS RAM Write 13 32-Bit Operating Register/SCRIPTS RAM Write 20 64-Bit Address Operating Register/SCRIPTS RAM Write 14 64-Bit Address Operating Register/SCRIPTS RAM Write Initiator Timing 21 Nonburst Opcode Fetch, 32-Bit Address and Data 15 Nonburst Opcode Fetch, 32-Bit Address and Data 22 Burst Opcode Fetch, 32-Bit Address and Data 16 Burst Opcode Fetch, 32-Bit Address and Data 23 Back-to-Back Read, 32-Bit Address and Data 17 Back-to-Back Read, 32-Bit Address and Data 24 Back-to-Back Write, 32-Bit Address and Data 18 Back-to-Back Write, 32-Bit Address and Data 25 Burst Read, 32-Bit Address and Data 19 Burst Read, 32-Bit Address and Data 26 Burst Read, 64-Bit Address and Data 20 Burst Read, 64-Bit Address and Data 27 Burst Write, 32-Bit Address and Data 21 Burst Write, 32-Bit Address and Data 28 Burst Write, 64-Bit Address and 32-Bit Data 22 Burst Write, 64-Bit Address and 32-Bit Data External Memory Timing 29 External Memory Read 23 External Memory Read STOP/ Driven by LSI53C875A 30 External Memory Write External Memory Write timings start on 24 External Memory Write Data Byte Enable Address out from MOE/, MCE/ High Driven by LSI53C875A Higher Valid Write Data CBE30 Byte Enable Data Byte Enable Out Lower Address Data LSI53C875A-Data Data Byte Enable Data Out Symbol Parameter Min Slow Memory ≤ 128 Kbytes Read Cycle Slow Memory ≤ 128 Kbytes Write Cycle 30 Slow Memory ≤ 128 Kbytes Write Cycle ≤ 64 Kbytes ROM Read Cycle ≤ 64 Kbyte ROM Write Cycle 32 ≤ 64 Kbyte ROM Write Cycle Scsi Timing Diagrams 37 Initiator Asynchronous Send 38 Initiator Asynchronous Receive 34 Initiator Asynchronous Receive 39 Target Asynchronous Send 35 Target Asynchronous Send 40 Target Asynchronous Receive 41 SCSI-1 Transfers 5.0 Mbytes Symbol Parameter Min Max Unit 37 Initiator and Target Synchronous Transfer Package Diagrams 38 LSI53C875A 160-Pin Pqfp Mechanical Drawing Pin Pqfp P3 Mechanical Drawing Sheet 2 Signal Pin 44 160 Pqfp Pin List by Location Pin BGA Mechanical Drawing 45 169 BGA Pin List by Location NC1 Appendix a Register Summary Table A.2 LSI53C875A Scsi Register Map Register Summary Scratch Registers C-RSCRATCHC-SCRATCHR Table A.2 LSI53C875A Scsi Register Map Register Summary Appendix B External Memory Interface Diagram Examples Figure B.2 64 Kbyte Interface with 150 ns Memory External Memory Interface Diagram Examples Figure B.4 512 Kbyte Interface with 150 ns Memory Symbols Index IX-2Index Numerics SGE 4-74,4-77 SI IX-4Index IX-5 IX-6Index IX-7 IX-8Index IX-9 IX-10Index Customer Feedback Reader’s Comments Excellent Good Average Fair Poor Distributors by State California New York Direct Sales Representatives by State Component and HAB Sales Offices and Design Resource Centers North America Korea International Distributors Australia Hong Kong