Kawasaki 80C51, KS152JB, 80C152 technical specifications DMA Arbitration

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KS152JB Universal Communications Controller Technical Specifications

If the DMA is in alternate cycles mode, then each time DMA cycle is completed DMXRQ goes to 0, thus de-activating HLD. Once HLD has been de-activate, it can’t be re-asserted till after HLDA has been to go high (through flip-flop Q1A). Thus every time the DMA is suspended to allow an instruction cycle to proceed, the requester gives up the bus and must renew the request and receive another acknowledge before another DMA cycle to XRAM can proceed. Obviously in this case, the “alternate cycles” mode may consist of single DMA cycles separated by any number of instruction cycles, depending on how long it takes the requester to regain the bus.

A channel 1 DMA in progress will always be overridden by a DMA request of any kind from channel 0. If a channel 1 DMA to XRAM is in progress and is over-ridden by a channel 0 DMA which does not require the bus, DMXRQ will go to 0 during the channel 0 DMA, thus de-activat- ing HLD. Again, the requester must re-new its request for the bus, and must receive a new 1-to-0 transition in HLDA before channel 1 can continue its DMA to XRAM.

4.4 DMA Arbitration

The DMA Arbitration described in this section is not arbitration between two devices wanting to access a shared RAM, but on-chip arbitration between the two DMA channels on the 8XC152.

The 8XC152 provides two DMA channels, either of which may be called into operation at any time in response to real time conditions in the application circuit. Since a DMA cycle always uses the 8XC152’s internal bus, and there’s only one internal bus, only one DMA channel can be ser- viced during a single DMA cycle. Executing program instructions also requires the internal bus, so program execution will also be suspended in order for a DMA to take place.

.

0

ARBITRA-

2

 

 

TION

 

 

 

LOGIC

 

 

DMAO

DMA 1

INSTRUCTION

 

 

 

CYCLE

CYCLE

CYCLE

 

 

 

WRITE

YES

 

 

TO

 

 

 

DMA

 

 

 

REG?

 

 

 

NO

 

Figure above shows the three tasks to which the internal bus of the 8XC152 can be dedicated. In this figure, Instruction Cycle means the complete execution of a single instruction, whether it takes 1,2 or 4 machine cycles. DMA Cycle means the transfer of a single data byte from source to destination, whether it takes 1 or 2 machine cycles. Each time a DMA Cycle or an Instruction

Kawasaki LSI USA, Inc.

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Ver. 0.9 KS152JB2

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Contents Introduction Technical Specifications Name Description Port Pin DescriptionPIN Description Pin Name Alternate FunctionRST XTAL1XTAL2 Eben ALEPsen EpsenSpecial function Registers SFR map for the cpuReset Timing Reset Values of the SFRs Sbuf Indeterminate Tmod ConfigurationsScon PconPort 0 I/O Pad Port 2 I/O Pad Port bit I/O PadsPorts 4,5 Comments ProgramPsen Epsen Fetch viaTIMER/COUNTERS Tmod Timer/Counter Mode Control RegisterTcon Timer/Counter Control Register ModeTimer/Counter in Mode Interrupts Timer/Counter 0 in ModeIE Interrupt Enable Register Priority Level Structure Egste EDMA1 Egstv EDMA0 Egsre Egsrv Pgste PDMA1 Pgstv PDMA0 Pgsre PgsrvPgsrv PX0EX0 Egsrv 2BHPT1 PDMA1EDMA1 ET1 1BHKawasaki LSI USA, Inc Ver .9 KS152JB2 ALE Psen Power Down and IdleStatus of the External Pins during Idle and Power Down Pcon Power Control Register Smod IDLLocal Serial Channel Local Serial Port Mode ControllerSerial Port Mode Mode Load Sbuf Baud Rates MHZ Timer 1 generated commonly used Baud ratesSmod Reti SINGLE-STEP OperationJNB Kawasaki LSI USA Inc Global Serial Channel Introduction11/IDLE CRC None DC JAM CRCCsma Sdlc 11/IDLEExternal 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 Collision Detection CSMA/CD Data EncodingManchester Encoding BIT Time Jitter ToleranceUnexpected 1-to-0 Transition Narrow PulsesMissing 0-to-1 Transition Response to a Detected Collision What the GSC was doing Resolution of CollisionsGSC Inactive TfifoAlgorithm BackoffDCR BKOFF= Myslot Random BackoffPrbs Tcdcnt Load Bkoff Slot Clock Myslot Deterministic Backoff Hardware Based Acknowledge Kawasaki LSI USA, Inc Ver .9 KS152JB2 Sdlc Frame Format BOF Address Control Info CRC EOFKawasaki LSI USA, Inc Ver .9 KS152JB2 BIT STUFFING/STRIPPING Data EncodingNrzi BIT Time Acknowledgement Sending Abort CharacterLine Idle Multi-Drop Network PRIMARY/SECONDARY StationsPoint-to-point Network Ring NetworkSdlc Hdlc Using a Preamble in SdlcHDLC/SDLC Comparison User Defined ProtocolsLine Discipline Planning for Network Changes and ExpansionsDMA Servicing of GSC Channels Kawasaki LSI USA, Inc Ver .9 KS152JB2 Baud Rate Initialization Test Modes External Driver InterfaceJitter Receive BIT Time Received Local Value Manchester Encoding BIT TimeReceive Sampling Rate Received Transmit WaveformsReceiver Clock Recovery CSMA/CD Clock RecoveryRcbat Crce Determining Receiver ErrorsExternal Clocking AddressingDetermining Line Discipline 2 CPU/DMA Control of the GSCCollisions and Backoff What the GSC was doing Response GSC Register Descriptions Successful Ending of Transmissions and ReceptionsGMOD84H Xtclk PL1 PL0 PL1 PL0 Length BitsKawasaki LSI USA, Inc Ver .9 KS152JB2 DCJ DCR SA5 SA4 SA3 SA2 SA1 SA0 ARB REQ Garen Xrclk Gfien IDLRcabt 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 Operation DMA with the 80C152DMA Registers DAS IDA Alternate Cycle ModeBurst Mode SAS ISASerial Port Demand Mode External Demand ModePCH P2 SFR DMA Cycle Resume Program Execution Timing Diagrams12 OSC.PERIODS ALE Psen P1 Inst Float DMA Transfer from Internal Memory to Internal MemoryDMA 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 Using the HOLD/HLDA Acknowledge ARB REQDmxrq 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 Summary of DMA Control Bits DAS IDA SAS ISA DoneInterrupt Structure IE0 TI+RI ET1 EX1 ET0 EX0PT1 PX1 PT0 PX0 IPN1GSC Transmitter Error Conditions Transmit Error Flags Logic for Clearing TEN, Setting TDNGSC 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 SM0 SM1 SM2 REN TB8 RB8 TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0Gate Kawasaki LSI USA, Inc 111 Ver .9 KS152JB2 Data Pointer LOW PortStack Pointer DPL.7 DPL.6 DPL5 DPL.4 DPL.3 DPL.2 DPL.1 DPL.0DPH.7 DPH.6 DPH.5 DPH.4 DPH.3 DPH.2 DPH.1 DPH.0 Timer ControlData Pointer High DPHTimer 0 LSB Timer Mode ControlGate Timer Timer 1 LSBTimer 0 MSB Timer 1 MSBSerial Data Buffer Serial Port ControlSM0 SBUF.7Program Status Word RS1 RS0Accumulator ACC.7 ACC.6 ACC.5 ACC.4 ACC.3 ACC.2 ACC.1 ACC.0Kawasaki LSI USA, Inc 119 Ver .9 KS152JB2 Kawasaki LSI USA, Inc 120 Ver .9 KS152JB2