Kawasaki 80C51, KS152JB, 80C152 technical specifications Hardware Based Acknowledge

Page 47

KS152JB Universal Communications Controller Technical Specifications

The highest slot assignment in the network is written by each station’s software into its TCDCNT register. Normal the highest slot assignment is just the total number of stations that are going to participate in the backoff algorithm.

In deterministic backoff mode a collision will not cause a 1 to be shifted into TCDCNT. TCDCNT will still be ANDed with PRBS and the result loaded into BKOFF. In order to insure that all sta- tions have the same value loaded into BKOFF, which determines the first slot number to occur, the PRBS should be loaded with OFFH; the PRBS will maintain this value until either the 8XC152 is reset or the user writes some other value into PRBS. After BKOFF is loaded it begins counting down slot times as soon as the IFS ends. Slot times are defined by the user, the same way as before, by loading SLOTTM with the number of bit times per slot.

When BKOFF equals the slot assignment (as defined in MYSLOT), the signal “BKOFF = MYS- LOT” in Figure shown above is asserted for one slot time, during which the GSC can restart its transmission.

While BKOFF is counting down, if any activity is detected at the GRXD pin, the countdown is frozen until the activity ends, a line idle condition is detected, and an IFS transpires. Then the countdown resumes from where it left off.

If a collision is detected at the GRXD pin while BKOFF is counting down, the collision resolution algorithm is restarted from the beginning.

In effect, the GSC “owns” its assigned slot number, but with one exception. Nobody owns slot number 0. Therefore if the GSC is assigned slot number 0, then when BKOFF=0, this station and any other station that has something to say at this time will have an equal chance to take the line.

3.2.7 HARDWARE BASED ACKNOWLEDGE

Hardware Based Acknowledge (HBA) is data link packet acknowledging scheme that the user software can enable with CSMA/CD protocol. It is not an option with SDLC protocol however.

In general HBA can give improved system response time and increased effective transmission rates over acknowledge schemes implemented in higher layers of the network architecture. Another benefit is the possibility of early release of the transmit buffer as soon as the acknowl- edge is received.

The acknowledge consists of a preamble followed by an idle condition. A receiving station with HABEN enabled will send an acknowledge only if the incoming address is unique to the receiving station and if the frame is determined to be correct with no errors. For the acknowledge to be sent, TEN must be set. For the transmitting station to recognize the acknowledge GREN must be set. A zero as the LSB of the address indicates that the address is unique and not a group or broadcast address. Errors can be caused by collisions, incorrect CRC, misalignment, or FIFO overflow. The receiver sends the acknowledge as soon as the line is sensed to be idle. The user must program the

Kawasaki LSI USA, Inc.

Page 47 of 120

Ver. 0.9 KS152JB2

Page 46 Page 48
Image 47
Page 46 Page 48
Contents Introduction Technical Specifications Pin Name Alternate Function Pin DescriptionPIN Description Name Description PortRST XTAL1XTAL2 Epsen ALEPsen EbenSFR map for the cpu Special function RegistersReset Timing Reset Values of the SFRs Pcon ConfigurationsScon Sbuf Indeterminate TmodPort bit I/O Pads Port 0 I/O Pad Port 2 I/O PadPorts 4,5 Fetch via ProgramPsen Epsen CommentsTmod Timer/Counter Mode Control Register TIMER/COUNTERSMode Tcon Timer/Counter Control RegisterTimer/Counter in Mode Interrupts Timer/Counter 0 in ModeIE Interrupt Enable Register Priority Level Structure Pgste PDMA1 Pgstv PDMA0 Pgsre Pgsrv Egste EDMA1 Egstv EDMA0 Egsre EgsrvEgsrv 2BH PX0EX0 PgsrvET1 1BH PDMA1EDMA1 PT1Kawasaki LSI USA, Inc Ver .9 KS152JB2 ALE Psen Power Down and IdleStatus of the External Pins during Idle and Power Down Smod IDL Pcon Power Control RegisterLocal Serial Channel Controller Local Serial Port ModeSerial Port Mode Mode Load Sbuf Baud Rates MHZ Timer 1 generated commonly used Baud ratesSmod Reti SINGLE-STEP OperationJNB Kawasaki LSI USA Inc Introduction Global Serial ChannelDC JAM CRC 11/IDLE CRC None11/IDLE Csma SdlcExternal clock Internal clock Control cpu Control dma Raw Receive Raw Transmit Preamble BOF Address Info CRC EOF CSMA/CD OverviewCSMA/CD Frame Format Kawasaki LSI USA, Inc Ver .9 KS152JB2 23 24 Interframe Space Jitter Tolerance CSMA/CD Data EncodingManchester Encoding BIT Time Collision DetectionUnexpected 1-to-0 Transition Narrow PulsesMissing 0-to-1 Transition Tfifo Resolution of CollisionsGSC Inactive Response to a Detected Collision What the GSC was doingAlgorithm BackoffDCR BKOFF= Myslot Random BackoffPrbs Tcdcnt Load Bkoff Slot Clock Myslot Deterministic Backoff Hardware Based Acknowledge Kawasaki LSI USA, Inc Ver .9 KS152JB2 BOF Address Control Info CRC EOF Sdlc Frame FormatKawasaki LSI USA, Inc Ver .9 KS152JB2 BIT STUFFING/STRIPPING Data EncodingNrzi BIT Time Acknowledgement Sending Abort CharacterLine Idle Ring Network PRIMARY/SECONDARY StationsPoint-to-point Network Multi-Drop NetworkUser Defined Protocols Using a Preamble in SdlcHDLC/SDLC Comparison Sdlc HdlcPlanning for Network Changes and Expansions Line DisciplineDMA Servicing of GSC Channels Kawasaki LSI USA, Inc Ver .9 KS152JB2 Baud Rate Initialization External Driver Interface Test ModesJitter Receive Transmit Waveforms Local Value Manchester Encoding BIT TimeReceive Sampling Rate Received BIT Time ReceivedCSMA/CD Clock Recovery Receiver Clock RecoveryAddressing Determining Receiver ErrorsExternal Clocking Rcbat Crce2 CPU/DMA Control of the GSC Determining Line DisciplineCollisions and Backoff What the GSC was doing Response Successful Ending of Transmissions and Receptions GSC Register DescriptionsPL1 PL0 Length Bits GMOD84H Xtclk PL1 PL0Kawasaki LSI USA, Inc Ver .9 KS152JB2 ARB REQ Garen Xrclk Gfien IDL DCJ DCR SA5 SA4 SA3 SA2 SA1 SA0Rcabt Crce RDN Rfne Gren Haben Kawasaki LSI USA, Inc Ver .9 KS152JB2 LNI Noack Tcdt TDN Tfnf TEN DMA Kawasaki LSI USA, Inc Ver .9 KS152JB2 DMA with the 80C152 DMA OperationDMA Registers SAS ISA Alternate Cycle ModeBurst Mode DAS IDAExternal Demand Mode Serial Port Demand ModeDMA Transfer from Internal Memory to Internal Memory Timing Diagrams12 OSC.PERIODS ALE Psen P1 Inst Float PCH P2 SFR DMA Cycle Resume Program ExecutionDMA Cycle Resume Program Execution 12 OSC. Periods ALE Psen Inst DMA Data OUT PCL Inst PCHDMA Cycle 12 OSC. Periods Resume Program Execution ALE Psen Hold/Hold Acknowledge Request ModeArbiter Mode ARB REQ Using the HOLD/HLDA AcknowledgeDmxrq ALE ARB If Hlda = ALE AEQ ALE REQInternal Logic of the Arbiter Internal Logic of the Requester DMA Arbitration Kawasaki LSI USA, Inc.oup, Inc Ver .9 KS152JB2 Kawasaki LSI USA, Inc Ver .9 KS152JB2 Kawasaki LSI USA, Inc Ver .9 KS152JB2 DMA Arbitration with Hold/Hold Ack DAS IDA SAS ISA Done Summary of DMA Control BitsInterrupt Structure IE0 ET1 EX1 ET0 EX0 TI+RIIPN1 PT1 PX1 PT0 PX0Transmit Error Flags Logic for Clearing TEN, Setting TDN GSC Transmitter Error ConditionsGSC Receiver Error Conditions Glossary Kawasaki LSI USA, Inc Ver .9 KS152JB2 DCON0/1 092H,093H Xtclk PL1 PL0 Kawasaki LSI USA, Inc 102 Ver .9 KS152JB2 Kawasaki LSI USA, Inc 103 Ver .9 KS152JB2 PT1 PX1 PT0 EX0 Myslot 0F5H DCJ DCR SA5 SA4 SA3 SA2 SA1 SA0 Smod ARB REQ Garen Xrclk Gfien IDL OVR Rcabt Crce RDN Rfne Gren Haben Kawasaki LSI USA, Inc 108 Ver .9 KS152JB2 TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 SM0 SM1 SM2 REN TB8 RB8Gate Kawasaki LSI USA, Inc 111 Ver .9 KS152JB2 DPL.7 DPL.6 DPL5 DPL.4 DPL.3 DPL.2 DPL.1 DPL.0 PortStack Pointer Data Pointer LOWDPH Timer ControlData Pointer High DPH.7 DPH.6 DPH.5 DPH.4 DPH.3 DPH.2 DPH.1 DPH.0Timer 1 LSB Timer Mode ControlGate Timer Timer 0 LSBTimer 1 MSB Timer 0 MSBSBUF.7 Serial Port ControlSM0 Serial Data BufferRS1 RS0 Program Status WordACC.7 ACC.6 ACC.5 ACC.4 ACC.3 ACC.2 ACC.1 ACC.0 AccumulatorKawasaki LSI USA, Inc 119 Ver .9 KS152JB2 Kawasaki LSI USA, Inc 120 Ver .9 KS152JB2
Top Page Image Contents