Kawasaki 80C51, KS152JB, 80C152 technical specifications DMA Servicing of GSC Channels

Page 56

KS152JB Universal Communications Controller Technical Specifications

Some of the general areas that will impact the overall scheme on how to incorporate future changes to the system are:

1)Communication of the change to all the stations or the primary station.

2)Maximum distance for communication. This will affect the drivers used and the slot time.

3)More stations may be on the line at one time. This may impact the interframe space or the col- lision resolution used.

4)If using CSMA/CD without deterministic resolution, any increase in network size will have a negative impact on the average throughput of the network and lower the efficiency. The user will have to give careful consideration when deciding how large a system can ultimately be and still maintain adequate performance.

3.5.3 DMA SERVICING OF GSC CHANNELS

There are two sources that can be used to control the GSC. The first is CPU control and the sec- ond is DMA control.

CPU control is used when user software takes care of the tasks such as: loading the TFIFO, read- ing the RDIFO, checking the status flags, and general tracking of the transmission process. As the number of tasks grow and higher data transfer rates are used, the overhead required by the CPU becomes the dominant consumption of time. Eventually, a point is reached where the CPU is spending 100% of its time responding to the needs of the GSC. An alternative is to have the DMA channels control the GSC

A detailed explanation on the general use of the DMA channels is covered in Section 4. In this section only those details required for the use of the DMA channels with the GSC will be covered.

The DMA channels can be configured by user software so that the GSC data transfers are serviced by the DA controller. Since there are two DMA channels, one channel can be used to service the receiver, and one channel can be used to service the transmitter. In using the DMA channels, the CPU is relived of much of the time required to do the basic servicing of the GSC buffers. The types of servicing that the DMA channels can provide are: loading of the transmit FIFO, remov- ing data from the receive FIFO, notification of the CPU when the transmission or reception has ended, and response to certain error conditions. When using the DMA channels the source or des- tination of the data intended for serial transmission can be internal data memory, external data memory, or any of the SFRs.

The only tasks required after initialization of the DMA and GSC registers are enabling the proper interrupts and informing the DMA controller when to start. After the DMA channels are started all that is required of the CPU is to respond to error conditions or wait until the end of transmis- sion.

Initialization of the DMA channels requires setting up the control, source, and destination address

Kawasaki LSI USA, Inc.

Page 56 of 120

Ver. 0.9 KS152JB2

Page 55 Page 57
Image 56
Page 55 Page 57
Contents Introduction Technical Specifications Pin Description PIN DescriptionName Description Port Pin Name Alternate FunctionRST XTAL1XTAL2 ALE PsenEben EpsenSpecial function Registers SFR map for the cpuReset Timing Reset Values of the SFRs Configurations SconSbuf Indeterminate Tmod PconPort 0 I/O Pad Port 2 I/O Pad Port bit I/O PadsPorts 4,5 Program Psen EpsenComments 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 PgsrvPX0 EX0Pgsrv Egsrv 2BHPDMA1 EDMA1PT1 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 CSMA/CD Data Encoding Manchester Encoding BIT TimeCollision Detection Jitter ToleranceUnexpected 1-to-0 Transition Narrow PulsesMissing 0-to-1 Transition Resolution of Collisions GSC InactiveResponse to a Detected Collision What the GSC was doing 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 PRIMARY/SECONDARY Stations Point-to-point Network Multi-Drop Network Ring NetworkUsing a Preamble in Sdlc HDLC/SDLC ComparisonSdlc Hdlc 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 Local Value Manchester Encoding BIT Time Receive Sampling Rate ReceivedBIT Time Received Transmit WaveformsReceiver Clock Recovery CSMA/CD Clock RecoveryDetermining Receiver Errors External ClockingRcbat Crce 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 Alternate Cycle Mode Burst ModeDAS IDA SAS ISASerial Port Demand Mode External Demand ModeTiming Diagrams 12 OSC.PERIODS ALE Psen P1 Inst FloatPCH P2 SFR DMA Cycle Resume Program Execution 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 Port Stack PointerData Pointer LOW DPL.7 DPL.6 DPL5 DPL.4 DPL.3 DPL.2 DPL.1 DPL.0Timer Control Data Pointer HighDPH.7 DPH.6 DPH.5 DPH.4 DPH.3 DPH.2 DPH.1 DPH.0 DPHTimer Mode Control Gate TimerTimer 0 LSB Timer 1 LSBTimer 0 MSB Timer 1 MSBSerial Port Control SM0Serial Data Buffer 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
Top Page Image Contents