Kawasaki 80C152, KS152JB, 80C51 technical specifications GSC Receiver Error Conditions

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KS152JB Universal Communications Controller Technical Specifications

The UR bit can be set only if the DMA bit in the TSTAT is set. The DMA bit being set informs the GSC hardware that TFIFO is being serviced by DMA. In that case if the GSC goes to fetch another byte from TFIFO and finds it empty, and the byte count register of the DMA channel ser- vicing TFIFO is not zero, it sets the UR bit.

If the DMA hardware is not being used to service TFIFO, the UR bit cannot get set. If the DMA bit is 0, then when the GSC finds TFIFO empty, it assumes that the transmission of data is com- plete and the transmission of CRC bits can begin.

The NOACK bit is functional only in CSMA/CD mode, and only when the HABEN bit in RSTAT is set. The HABEN bit turns on the Hardware Based Acknowledge feature, as described in Sec- tion 3.2.6. If this feature is not invoked, the NOACK bit will stay at 0.

If the NOACK bit gets set, it means the GSC has completed a transmission, and was expecting to receive a hardware based acknowledge from the receiver of the message, but did not receive the acknowledge, or at least did not receive it cleanly. There are three ways the NOACK can get set:

1.The acknowledge signal (an unattached preamble) was not received before the IFS was com- plete.

2.A collision was detected during the IFS

3.The line was active during the last bit-time of the IFS

The first condition is an obvious reason for setting the NOACK bit, since that’s what the hardware based acknowledge is for. The other two ways the NOACK bit can get set are to guard against the possibility that the transmitting station might mistake an unrelated transmission or transmission fragment for an acknowledge signal.

5.2 GSC Receiver Error Conditions

The GSC Receiver section reports four kinds of error conditions:

CRCE - CRC error

AE - Alignment Error

RCABT - Receive Abort

OVR - Overrun in Receive FIFO

These bits reside in the RSTAT register. User software can read them, but only GSC hardware can write to them. The GSC hardware will set them in response to the various error conditions that they represent. When user software sets the GREN bit, the GSC hardware will at that time clears these flags. This is the only way these flags can be cleared.

The logical OR of these four bits flags the GSC Receive Error interrupt (GSCRE) and clears the GREN bit, as shown in Figure below. Note in this figure that any error condition will prevent

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Ver. 0.9 KS152JB2

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Contents Introduction Technical Specifications PIN Description Pin DescriptionName Description Port Pin Name Alternate FunctionXTAL2 XTAL1RST Psen ALEEben EpsenSFR map for the cpu Special function RegistersReset Timing Reset Values of the SFRs Scon ConfigurationsSbuf Indeterminate Tmod PconPort bit I/O Pads Port 0 I/O Pad Port 2 I/O PadPorts 4,5 Psen Epsen ProgramComments Fetch viaTmod Timer/Counter Mode Control Register TIMER/COUNTERSMode Tcon Timer/Counter Control RegisterTimer/Counter in Mode IE Interrupt Enable Register Timer/Counter 0 in ModeInterrupts Priority Level Structure Pgste PDMA1 Pgstv PDMA0 Pgsre Pgsrv Egste EDMA1 Egstv EDMA0 Egsre EgsrvEX0 PX0Pgsrv Egsrv 2BHEDMA1 PDMA1PT1 ET1 1BHKawasaki LSI USA, Inc Ver .9 KS152JB2 Status of the External Pins during Idle and Power Down Power Down and IdleALE Psen Smod IDL Pcon Power Control RegisterLocal Serial Channel Controller Local Serial Port ModeSerial Port Mode Mode Load Sbuf Baud Rates Smod Timer 1 generated commonly used Baud ratesMHZ JNB SINGLE-STEP OperationReti 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 CSMA/CD Frame Format CSMA/CD OverviewPreamble BOF Address Info CRC EOF Kawasaki LSI USA, Inc Ver .9 KS152JB2 23 24 Interframe Space Manchester Encoding BIT Time CSMA/CD Data EncodingCollision Detection Jitter ToleranceMissing 0-to-1 Transition Narrow PulsesUnexpected 1-to-0 Transition GSC Inactive Resolution of CollisionsResponse to a Detected Collision What the GSC was doing TfifoDCR BackoffAlgorithm Prbs Tcdcnt Load Bkoff Slot Clock Myslot Random BackoffBKOFF= 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 Nrzi BIT Time Data EncodingBIT STUFFING/STRIPPING Line Idle Sending Abort CharacterAcknowledgement Point-to-point Network PRIMARY/SECONDARY StationsMulti-Drop Network Ring NetworkHDLC/SDLC Comparison Using a Preamble in SdlcSdlc Hdlc User Defined ProtocolsPlanning 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 Receive Sampling Rate Received Local Value Manchester Encoding BIT TimeBIT Time Received Transmit WaveformsCSMA/CD Clock Recovery Receiver Clock RecoveryExternal Clocking Determining Receiver ErrorsRcbat Crce Addressing2 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 Burst Mode Alternate Cycle ModeDAS IDA SAS ISAExternal Demand Mode Serial Port Demand Mode12 OSC.PERIODS ALE Psen P1 Inst Float Timing DiagramsPCH P2 SFR DMA Cycle Resume Program Execution DMA Transfer from Internal Memory to Internal MemoryDMA Cycle 12 OSC. Periods Resume Program Execution ALE Psen 12 OSC. Periods ALE Psen Inst DMA Data OUT PCL Inst PCHDMA Cycle Resume Program Execution Arbiter Mode Request ModeHold/Hold Acknowledge ARB REQ Using the HOLD/HLDA AcknowledgeInternal Logic of the Arbiter ALE ARB If Hlda = ALE AEQ ALE REQDmxrq 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 Stack Pointer PortData Pointer LOW DPL.7 DPL.6 DPL5 DPL.4 DPL.3 DPL.2 DPL.1 DPL.0Data Pointer High Timer ControlDPH.7 DPH.6 DPH.5 DPH.4 DPH.3 DPH.2 DPH.1 DPH.0 DPHGate Timer Timer Mode ControlTimer 0 LSB Timer 1 LSBTimer 1 MSB Timer 0 MSBSM0 Serial Port ControlSerial Data Buffer SBUF.7RS1 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
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