Kawasaki 80C152, KS152JB, 80C51 Hold/Hold Acknowledge, Request Mode, Arbiter Mode

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KS152JB Universal Communications Controller Technical Specifications

4.3 Hold/Hold Acknowledge

Two operating modes of Hold/Hold Acknowledge logic are available, and either or neither may be invoked by software. In one mode, the C152 generates a Hold Request signal and awaits a Hold Acknowledge response before commencing a DMA that involves external RAM. This is called the Requester Mode.

In the other mode, the C152 accepts a Hold Request signal from an external device and generates a Hold Acknowledge signal in response, to indicate to the requesting device that the C152 will not commence a DMA to or from external RAM while the Hold Request is active. This is called the Arbiter mode.

4.3.1 REQUEST MODE

The Requester Mode is selected by setting the control bit REQ, which resides in PCON. In that mode, when the C152 wants to do a DMA to External Data Memory, it first generates a Hold Request signal, HLD, and waits for a Hold Acknowledge signal, HLDA, before commencing the DMA operation. Note that program execution continues while HLDA is awaited. The DMA is not begun until a logical 0 is detected at the HLDA pin. Then, once the DMA has begun, it goes to completion regardless of the logic level at HLDA.

The protocol is activated only for DMA (not for program fetches or MOVX operations), and only for DMAs to or from External Data Memory. If the data destination and source are both internal to the C152, the HLD/HLDA protocol is not used.

The HLD output is an alternate function of port pin P1.5, and the HLDA input is an alternate function of port pin P1.6

4.3.2 ARBITER MODE

For DMAs that are to be driven by some device other than the C152, a different version of the Hold/Hold Acknowledge protocol is available. In this version, the device which is to drive the DMA sends a Hold Request signal, HLD, to the C152. I f the C152 is currently performing a DMA to or from External Data Memory, it will complete this DMA before responding to the Hold Request. When the C152 responds to the Hold Request, it does so by activating a Hold Acknowl- edge signal, HLDA. This indicates that the C152 will not commence a new DMA to or from External Data Memory while HLD remains active.

Note that in the Arbiter Mode the C152 does not suspend program execution at all, even if it is executing from external program memory. It does not surrender use of its own bus.

The Hold Request input, HLD, is at P1.5. The Hold Acknowledge output, HLDA, is at P1.6. This version of the Hold/Hold Acknowledge feature is selected by setting the control bit ARB in PCON.

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 FunctionXTAL2 XTAL1RST 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 IE Interrupt Enable Register Timer/Counter 0 in ModeInterrupts 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 Status of the External Pins during Idle and Power Down Power Down and IdleALE Psen Pcon Power Control Register Smod IDLLocal Serial Channel Local Serial Port Mode ControllerSerial Port Mode Mode Load Sbuf Baud Rates Smod Timer 1 generated commonly used Baud ratesMHZ JNB SINGLE-STEP OperationReti 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 CSMA/CD Frame Format CSMA/CD OverviewPreamble BOF Address Info CRC EOF Kawasaki LSI USA, Inc Ver .9 KS152JB2 23 24 Interframe Space Collision Detection CSMA/CD Data EncodingManchester Encoding BIT Time Jitter ToleranceMissing 0-to-1 Transition Narrow PulsesUnexpected 1-to-0 Transition Response to a Detected Collision What the GSC was doing Resolution of CollisionsGSC Inactive TfifoDCR BackoffAlgorithm Prbs Tcdcnt Load Bkoff Slot Clock Myslot Random BackoffBKOFF= 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 Nrzi BIT Time Data EncodingBIT STUFFING/STRIPPING Line Idle Sending Abort CharacterAcknowledgement 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 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 Using the HOLD/HLDA Acknowledge ARB REQInternal 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 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
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