SCF20 Synchronous Clock Conversion Factor, Ews | LSI 53C875A

SCF[2:0]	Synchronous Clock Conversion Factor	[6:4]
	These bits select a factor by which the frequency of
	SCLK is divided before being presented to the
	synchronous SCSI control logic. Write these to the same
	value as the Clock Conversion Factor bits below unless
	fast SCSI operation is desired. See the SCSI Transfer
	(SXFER) register description for examples of how the
	SCF bits are used to calculate synchronous transfer
	periods. See the table under the description of bits [7:5]
	of the SXFER register for the valid combinations.

EWS	Enable Wide SCSI	3
	When this bit is clear, all information transfer phases are
	assumed to be eight bits, transmitted on SD[7:0]/ and
	SDP0/. When this bit is asserted, data transfers are done
	16 bits at a time, with the least significant byte on
	SD[7:0]/ and SDP0/ and the most significant byte on
	SD[15:8]/, SDP1/. Command, Status, and Message
	phases are not affected by this bit.

CCF[2:0]	Clock Conversion Factor				[2:0]
	These bits select a factor by which the frequency of
	SCLK is divided before being presented to the SCSI core.
	The synchronous portion of the SCSI core can be run at
	a different clock rate for fast SCSI, using the
	Synchronous Clock Conversion Factor bits. The bit
	encoding is displayed in the table below. All other
	combinations are reserved.

	SCF2	SCF1	SCF0	Factor	SCSI Clock
	CCF2	CCF1	CCF0	Frequency	(MHz)

	0	0	0	SCLK/3	50.01–75.0

	0	0	1	SCLK/1	16.67–25.0

	0	1	0	SCLK/1.5	25.01–37.5

	0	1	1	SCLK/2	37.51–50.0

	1	0	0	SCLK/3	50.01–75.0

	1	0	1	SCLK/4	75.01–80.00

	1	1	0	SCLK/6	120

	1	1	1	SCLK/8	160

Note: It is important that these bits are set to the proper values to guarantee that the LSI53C875A meets the SCSI timings as defined by the ANSI specification.

SCSI Registers

4-29

Image 121

LSI 53C875A SCF20 Synchronous Clock Conversion Factor, Ews, Enable Wide Scsi, CCF20 Clock Conversion Factor

Contents

C e m b e r 2 0 0 Technical Manual Trademark Acknowledgment Organization Audience Ansi Conventions Used in This Manual PCI Special Interest GroupRevision Record 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 Benefits of Ultra Scsi New Features in the LSI53C875A LSI53C875A Benefits Summary TolerANT Technology Scsi Performance Integration PCI PerformanceEase of Use Scripts RAM Flexibility Testability Reliability Chapter Functional Description PCI Addressing PCI Functional Description Configuration Space PCI Bus Commands and Functions Supported Interrupt Acknowledge Command PCI Bus Commands and Encoding Types for the LSI53C875ASpecial Cycle Command CBE30 Command Type Supported as Master Supported as Slave 2.4 I/O Write Command 2.3 I/O Read CommandReserved 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 Issuing Cache Commands Enabling Cache Mode Memory Write Caching Memory Read Caching Host Memory PCI Cache Mode Alignment Read Example Examples Write Example Write Example Memory-to-Memory Moves Scsi Functional Description Scripts Processor Phase Mismatch Handling in Scripts Internal Scripts RAM Hardware Control of Scsi Activity LED 3 64-Bit Addressing in Scripts Designing an Ultra Scsi System Using the Scsi Clock Quadrupler Prefetching Scripts Instructions Load and Store Instructions Opcode Fetch Burst Capability Scsi Loopback Mode Jtag Boundary Scan Testing Parity Options Bit Name Location Description Bits Used for Parity Control and Generation Scsi Parity Control Scsi Parity Errors and Interrupts Parity Checking/Generation DMA Fifo Data Paths DMA Fifo Sections Asynchronous Scsi Send LSI53C875A Host Interface Scsi Data Paths Synchronous Scsi Send Synchronous Scsi Receive Asynchronous Scsi Receive Scsi Termination Scsi Bus Interface Regulated Termination for Ultra Scsi Select/Reselect During Selection/Reselection Determining the Data Transfer Rate Synchronous Operation Determining the Synchronous Transfer Rate Scsi Control Three SCNTL3 Register, Bits 20 CCF20 Scsi Control Three SCNTL3 Register, Bits 64 SCF20Scsi Transfer Sxfer Register, Bits 75 TP20 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 Read Interrupt Status Zero ISTAT0 Sample Interrupt Service Routine Chained Block Moves Wide Scsi Send Bit Block Move and Chained Block Move Instructions Swide Register Wide Scsi Receive BitSodl Register Chained Block Move Scripts Instruction Parallel ROM Interface MAD31 Available Memory Space Parallel ROM Support Serial Eeprom Interface Default Download Mode No Download Mode Power ManagementMode a Serial Eeprom Data Format Byte Name Description Power State D1 Power State D0Power States Configuration Register Bits Power State D3 Power State D2 Functional Description Chapter Signal Descriptions LSI53C875A Functional Signal Grouping LSI53C875A Functional Signal Grouping Internal Pull-ups on LSI53C875A Signals Signal DescriptionsSignal Name Pull-up Current Conditions for Pull-up 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 Error Reporting Signals Arbitration SignalsArbitration Signals Error Reporting Signals Interrupt Signal Scsi Bus Interface SignalsScsi Bus Interface Signal Interrupt Signal Scsi Control Signals Scsi SignalsScsi Signals 10 Scsi Control Signals 11 Gpio Signals Gpio SignalsScsi General Purpose I/O pin. Optionally Scsi General Purpose I/O pin. This pin 12 ROM Flash and Memory Interface Signals ROM Flash and Memory Interface Signals 13 Test Interface Signals Test Interface SignalsMemory Address/Data Bus. This bus is used 14 Power and Ground Signals Power and Ground Signals MAD Bus Programming 15 Decode of MAD Pins MAD Bus Programming Signal Descriptions Chapter Registers PCI Configuration Registers Vendor ID Read Only RegistersVIDVendor ID150 Enable Parity Error Response Command Read/WriteDevice ID Read Only DIDDevice ID150 EBM WIEEMS EIS SSE DPERMA RTA DPR RegisterRevision ID Rev ID Read Only RIDRevision ID70 Register 0x0C Registers 0x09-0x0B Register 0x0E Register 0x0DRegister 0x0F BAR1 BAR0 Registers 0x1C-0x27 Registers 0x18-0x1BRegisters 0x28-0x2B Registers 0x2C-0x2D Subsystem ID Read Only Registers 0x2E-0x2FSID Subsystem ID 150 Erba Expansion ROM Base Address Read/WriteExpansion ROM Base Address 310 Register 0x3C Registers 0x35-0x3BCapabilities Pointer Read Only CPCapabilities Pointer70 Interrupt Line Read/Write ILInterrupt Line70 Register 0x3E Register 0x3DRegister 0x3F MGMINGNT70 Pmes D1S D2SDSI APS Dslt DsclPEN Bridge Support Extensions Pmcsrbse Read Only Data Read Only Scsi RegistersDATAData70 Scsi Register Address Map Arbitration Mode ARB10 Arbitration Mode Bits 1Scsi Control Zero SCNTL0 Read/Write Simple Arbitration Start Start Sequence5 Full Arbitration, Selection/Reselection EPC WatnAAP ADB EXCDHP RST CONAesp Iarb SSTStart Scsi Transfer0 Scsi Control Two SCNTL2 Read/Write Chained ModeSDU Scsi Disconnect Unexpected Slphben SlpmdWSS VUE0 WSRWide Scsi Receive0 Ultra Scsi EnableScsi Control Three SCNTL3 Read/Write USE SCF20 Synchronous Clock Conversion Factor Enable Wide ScsiEWS CCF20 Clock Conversion Factor SRE RREENC TP20 Scsi Synchronous Transfer Period Scsi Transfer Sxfer Read/Write Transfer Rate Synch CLK MHzBits Period ns Mbytes/s MO40 Max Scsi Synchronous Offset Synchronous Offset Maximum Synchronous Offset Encoded Destination Scsi ID Scsi Destination ID Sdid Read/WriteGeneral Purpose GPREG0 Read/Write Gpio Sfbr Scsi First Byte Received70 Scsi First Byte Received Sfbr Read/Write ACK REQBSY SEL Register 0x0B Register 0x0AVAL Enid SACK/ Status SREQ/ StatusSBSY/ Status SSEL/ Status Abrt MdpeSSI SIR Scsi Registers ORF ILFOLF LOA AIPWOA Bytes or Words Scsi Synchronous Data Fifo Word CountSSTAT2 bit SDP0L ORF1 ILF1OLF1 Ldsc SPL1SDP1 DSA Interrupt Status Zero ISTAT0 Read/Write Srst Software Reset6Abort Operation Sigp Signal ProcessSEM Semaphore Dipdma Interrupt Pending0 Sipscsi Interrupt Pending1 Srun FlshSyncirqd MBOX0 Mailbox Zero70 Mailbox Zero MBOX0 Read/WriteMailbox One MBOX1 Read/Write MBOX1 Mailbox One70 FMTByte Empty in DMA FIFO70 Chip Test Zero CTEST0 Read/WriteChip Test One CTEST1 Read Only FFLByte Full in DMA FIFO70 Ddir Register 0x1ACIO Dreq TeopDack FLF Register 0x1BCLF Temp Registers 0x1C-0x1FDMA Fifo Dfifo 58Registers FBL3 BdisZSD Srtm Chip Test Five CTEST5 Read/Write FBL20 Fifo Byte ControlAdck Clock Address Incrementor DFS BbckMasr BL2 DBC Dfdma FIFO70 Dcmd DMA Command70 DMA Command Dcmd Read/Write Dnad Registers 0x2C-0x2FDSP Dsps DMA Scripts Pointer Save310 DMA Scripts Pointer Save Dsps Read/WriteScratch Register a Scratcha Read/Write Scratcha Scratch Register a 310 BL10 Burst Length DMA Mode Dmode Read/Write Destination I/O Memory Enable Source I/O Memory EnableERLEnable Read Line3 Siom Burst Opcode Fetch Enable Enable Read MultipleErmp BOF Master Data Parity Error Bus Fault DMA Interrupt Enable Dien Read/WriteScripts Interrupt Instruction Received Reserved Illegal Instruction Detected Register 0x3B Register 0x3AClse PFF SSM Single Step ModeIrqmirq Mode3 STDStart DMA Operation2 IRQ DisableIrqd COMLSI53C700 Compatibility0 0x40 Registers 0x3C-0x3FAdder RSL CMPSGE UDC GEN STO 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 Scsi RST/ Received Parity ErrorPAR Scsi Interrupt Status One SIST1 Read Only HTH Handshake-to-Handshake Timer ExpiredScsi Longitudinal Parity Slpar Read/Write Slpar Scsi Longitudinal Parity70 Data Bytes Running Slpar Scsi Wide Residue Swide Read/Write Memory Access Control Macntl Read/WriteSwide Scsi Wide Residue70 TYP DRD DWRPscpt Scpts Scripts Gpiogpio Enable10 Gpio EnableScsi Timer Zero STIME0 Read/Write HTH30 Handshake-to-HandshakeTimer Period SEL30 Selection Time-Out30 Gensf HthbaHthsf Register 0x4B Register 0x4A Ssaid Register 0x4CSLT ART Sclk Register 0x4DISO QEN Qsel Register 0x4ESCE ROF AWS SZMEXT LOW STR Register 0x4F Timer Test Mode Disable Single Initiator ResponseS16 Bit System TTM Scsi Input Data Latch Sidl Read Only STWSidlscsi Input Data Latch150 Lock Register 0x53 Chip Control 0 CCNTL0 Read/Write Enable Phase Mismatch JumpEnpmj Pmjctl Jump Control6 Disfc EnndjDils Ddac Zmode64TIMOD EN64TIBMV Enable 64-Bit Direct BmovEN64DBMV Scsi Bus Data Lines Sbdl Read Only Register 0x5A-0x5B 64-Bit Scripts SelectorsRegisters 0x5C-0x5F Registers 0x60-0x9F Memory Move Read Selector Mmrs Read/Write Registers 0xA0-0xA3Mmrs Memory Move Read Selector Mmrs Registers 0xA8-0xAB Registers 0xA4-0xA7Mmws SFS Registers 0xB0-0xB3 Registers 0xAC-0xAFDRS Sbms Registers 0xB4-0xB7 Phase Mismatch Jump RegistersRegisters 0xB8-0xBB Registers 0xBC-0xBF Registers 0xC4-0xC7 Registers 0xC0-0xC3PMJAD1 PMJAD2 Registers 0xCC-0xCF Registers 0xC8-0xCBRBC Entry Storage Address ESA Read/Write Registers 0xD0-0xD3ESA Entry Storage Address 310 Registers 0xD8-0xDA Registers 0xD4-0xD7SBC Registers 0xDC-0xDF Register 0xDBRegisters 0xE0-0xFF Csbc Scsi Scripts Low Level Register Interface Mode High Level Scsi Scripts Mode Scripts Instructions Sample OperationInstruction Description Scsi Scripts Instruction Set Scripts Overview First Dword Block Move Instruction 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 I/O Instruction Target Mode Initiator ModeSecond Dword Start Address 310 OPC20 OpCode 2927 IT10 Instruction Type I/O Instruction 3130Reselect Instruction Instruction Defined Wait Select Instruction Disconnect InstructionSet Instruction Clear Instruction Select Instruction Wait Reselect Instruction Wait Disconnect Instruction TITable Indirect Mode25 Relative Addressing Mode Table Indirect DirectRelative Bit Table Relative Command Table Offset Absolute Jump Offset Set/Clear Satn Set/Clear Sack Reserved IT10 Instruction Type Read/Write Instruction 3130 Read/Write InstructionsO20 Operator 2624 Use data8/SFBR A60 Register Address A60 2216 Read-Modify-Write Cycles Read/Write Instructions Move To/From Sfbr Cycles Transfer Control Instructions Transfer Control Instructions IT10 Instruction Type Transfer Control 3130Jump Instruction Return Instruction Call Instruction Interrupt-on-the-Fly Instruction Interrupt Instruction RARelative Addressing Mode23 Scsi Phase ComparisonsJump/Call an Absolute Address Jump/Call a Relative Address JMP Bit 2 is assertedJump If True/False Wait for Valid Phase Compare PhaseCompare Data WVP DCV Memory Move InstructionsData Compare Value Jump Address 310 Reserved 2825 IT20 Instruction Type Memory Move 3129No Flush Dsps Register 310 Read/Write System Memory from Scripts Third Dword Load and Store InstructionsTemp Register 310 Bit A1 Bit A0 Number of Bytes Allowed to Load and Store DSA Relative IT20 Instruction Type 3129Reserved 2726 No Flush Store instruction only Bit Source Destination DMA Control Dcntl register is set This bit has no effect unless the Prefetch Enable bit Scsi Scripts Instruction Set DC Characteristics Chapter Electrical Specifications Absolute Maximum Stress Ratings1 Symbol Parameter Min Max Unit Test ConditionsOperating Conditions1 Input Capacitance Bidirectional Signals-GPIO0FETCH/, GPIO1MASTER/, GPIO24 Bidirectional Signals-MAD70, MAS/10, MCE/, MOE/, MWE Output Signal-TDO Output Signals-IRQ/, MAC/TESTOUT, REQ TolerANT Technology Electrical CharacteristicsOutput Signal-SERR Pqfp Symbol Parameter Min1 Max Unit Test Conditions Rise and Fall Time Test Condition Input Current as a Function of Input Voltage Symbol Parameter Min Max Unit AC Characteristics12 External Clock1 Interrupt Output Reset Input PCI and External Memory Interface Timing Diagrams Electrical Specifications PCI Configuration Register Read 15 PCI Configuration Register ReadTarget Timing 10 PCI Configuration Register Write 16 PCI Configuration Register Write 11 32-Bit Operating Register/SCRIPTS RAM Read 17 32-Bit Operating Register/SCRIPTS RAM Read 12 64-Bit Address Operating Register/SCRIPTS RAM Read 18 64-Bit Address Operating Register/SCRIPTS RAM Read 13 32-Bit Operating Register/SCRIPTS RAM Write 19 32-Bit Operating Register/SCRIPTS RAM Write 14 64-Bit Address Operating Register/SCRIPTS RAM Write 20 64-Bit Address Operating Register/SCRIPTS RAM Write 21 Nonburst Opcode Fetch, 32-Bit Address and Data Initiator Timing 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 29 External Memory Read External Memory Timing 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 Slow Memory ≤ 128 Kbytes Read Cycle Symbol Parameter Min 30 Slow Memory ≤ 128 Kbytes Write Cycle Slow Memory ≤ 128 Kbytes Write Cycle ≤ 64 Kbytes ROM Read Cycle 32 ≤ 64 Kbyte ROM Write Cycle ≤ 64 Kbyte ROM Write Cycle 37 Initiator Asynchronous Send Scsi Timing Diagrams 34 Initiator Asynchronous Receive 38 Initiator Asynchronous Receive 35 Target Asynchronous Send 39 Target Asynchronous Send 41 SCSI-1 Transfers 5.0 Mbytes 40 Target Asynchronous Receive Symbol Parameter Min Max Unit 37 Initiator and Target Synchronous Transfer 38 LSI53C875A 160-Pin Pqfp Mechanical Drawing Package Diagrams Pin Pqfp P3 Mechanical Drawing Sheet 2 44 160 Pqfp Pin List by Location Signal Pin Pin BGA Mechanical Drawing NC1 45 169 BGA Pin List by Location 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 Index Symbols IX-2Index SGE 4-74,4-77 SI Numerics IX-4Index IX-5 IX-6Index IX-7 IX-8Index IX-9 IX-10Index Customer Feedback Excellent Good Average Fair Poor Reader’s Comments California Distributors by State New York Direct Sales Representatives by State Component and HAB North America Sales Offices and Design Resource Centers Korea Australia Hong Kong International Distributors