SMC Networks PL241, AHB SRAM/NOR manual Direct commands, Device pin mechanism, Software mechanism

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Functional Overview

Direct commands

The SMC enables code to be executed from the memory while simultaneously, from the software perspective, moving the same chip to a different operating mode. This is achieved by synchronizing the update of the chip configuration registers from the holding registers with the dispatch of the memory configuration register write.

The SMC provides two mechanisms for simultaneously updating the controller and memory configuration registers.

Device pin mechanism

For memories that use an input pin to indicate that a write is intended for the configuration register, for example in some PSRAM devices, the write mechanism can be done through the APB direct command register. Figure 2-12 on page 2-25shows the sequence of events.

Software mechanism

For memories that require a sequence of read and write commands, for example, most NOR Flash devices use the SMC interface, with the write data bus indicating when the last transfer has completed and when it is safe for the SMC to update the chip configuration registers. Figure 2-13 on page 2-26shows the sequence of events.

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Copyright © 2006 ARM Limited. All rights reserved.

ARM DDI 0389B

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Contents PrimeCell AHB SRAM/NOR Memory Controller PL241 Copyright 2006 ARM Limited. All rights reserved PrimeCell AHB SRAM/NOR Memory Controller PL241Technical Reference Manual Contents Chapter Programmer’s Model for Test List of Tables List of Tables List of Figures Figure A-1 AHB MC PL241 grouping of signals Preface Feedback onUsing this manual About this manualProduct revision status Intended audienceBold ConventionsTypographical Timing diagrams SignalsARM publications NumberingFurther reading Feedback on this manual FeedbackFeedback on this product Introduction SMC on About the AHB MCThis section describes AHB interface AHB to APB bridgeClock domains Low-power interfaces3 SMC Supported devices Intel W18 series NOR FLASH, for example 28f128W18tdIntroduction Copyright 2006 ARM Limited. All rights reserved Functional Overview Functional description This section is divided intoSmcmreset0n Low-power interfaceAHB clock domain Static memory clock domainSMC Main blocks of the SMC areFormat on Interrupts onSMC interface APB slave interfaceFormat Memory managerPad interface InterruptsAHB fixed burst types Functional operationAHB interface operation Broken bursts Bufferable bit of the Hprot signalUndefined length Incr bursts Locked transfers AHB response signalsRead after write hazard detection buffer Big-endian 32-bit mode Removal of AHB error response logicRegistered Hwdata AHB to APB bridge operationClock domain operation Ahbc memory mapLow-power interface operation Static memory clocking options1lists the static memory clocking options Static memory clocking optionsWhere Domain is ahb or smc An active output DomaincactiveAccepting requests SMC states are as follows SMC functional operationOperating states Clocking and resets ClockingResets Miscellaneous signals Smcuserconfig70Smcuserstatus70 Smcagtm0syncHazard handling APB slave interface operationFormat block Sram memory accesses Memory burst length Memory manager operation Low-power operationChip configuration registers 11 Chip configuration registers Software mechanism Direct commandsDevice pin mechanism 12 Device pin mechanism 13 Software mechanism Memory interface operation Sram timing tables and diagramsInterrupts operation Asynchronous read opmode chip register settings Asynchronous read Sram cycles register settings4and -5list the smcopmode00-3 and Sram Register settings 14 Asynchronous readAsynchronous write Sram cycles register settings 6and -7list the smcopmode00-3 and Sram Register settingsAsynchronous write opmode chip register settings 10 Page read opmode chip register settings 8and -9list the smcopmode00-3 and Sram Register settings10and -11list the smcopmode00-3 and Sram Register settings 13 Synchronous burst read Sram cycles register settings 12and -13list the smcopmode00-3 and Sram Register settings12 Synchronous burst read opmode chip register settings 19 Synchronous burst read 14and -15list the smcopmode00-3 and Sram Register settings 20 Synchronous burst read in multiplexed-mode17 Synchronous burst write Sram cycles register settings 16and -17list the smcopmode00-3 and Sram Register settings16 Synchronous burst write opmode chip register settings 18and -19list the smcopmode00-3 and Sram Register settings 22 Synchronous burst write in multiplexed-mode20and -21list the smcopmode00-3 and Sram Register settings B0100 B0110 B001TCEOE is only required if wait is asserted when oen goes LOW TWC = ARM DDI 0389B Programmer’s Model About the programmer’s model 2shows the SMC configuration register map Register summaryName Base offset Type Reset value Description 1lists the SMC RegistersRegister summary Register descriptions This section describes the SMC registersSMC Memory Controller Status Register at 2lists the register bit assignmentsBits Name Function SMC Memory Interface Configuration Register at3lists the register bit assignments SMC Set Configuration Register at Smcmemccfgset Register bit assignmentsSMC Clear Configuration Register at 0x100C 4lists the register bit assignments5lists the register bit assignments Smcmemccfgclr Register bit assignments Bits Name FunctionSmcdirectcmd Register bit assignments SMC Direct Command Register at6lists the register bit assignments SMC Set Cycles Register at Lists the register bit assignmentsSMC Set Opmode Register at 12 smcsetopmode Register bit assignments8lists the register bit assignments Smcsetopmode Register bit assignments Memory width mw fieldSmcrefreshperiod0 Register bit assignments SMC Refresh Period 0 Register atSMC Sram Cycles Registers 0-3 at 0x1100, 0x1120, 0x1140 10lists the register bit assignments SMC Opmode Registers 0-3 at 0x1104, 0x1124, 0x114411lists the register bit assignments SMC User Status Register at 12lists the register bit assignments11 smcopmode Register bit assignments 12 smcuserstatus Register bit assignmentsSMC User Configuration Register at 13 smcuserconfig Register bit assignments13 lists the register bit assignments Bits Name Description15 smcperiphid0 Register bit assignments Bits Name Function Following section describe the smcperiphid RegistersSMC Peripheral Identification Register 16 smcperiphid1 Register bit assignments Bits Name Function 17 smcperiphid2 Register bit assignments Bits Name FunctionSMC PrimeCell Identification Registers 0-3 at 0x1FF0-0x1FFC 19shows the register bit assignmentsThese registers cannot be read in the Reset state Following sections describe the smcpcellid RegistersSMC PrimeCell Identification Register 20 smcpcellid0 Register bit assignments Bits Name Function22 smcpcellid2 Register bit assignments Bits Name Function 23 smcpcellid3 Register bit assignments Bits Name FunctionProgrammer’s Model for Test Test registers are provided for integration testing SMC Integration Configuration Register at 0x1E00SMC integration test registers Lists the SMC integration test registersIntegration Inputs Register at 0x1E04 Smcintinputs Register bit assignments Bits Name FunctionIntegration Outputs Register at 0x1E08 StateDevice Driver Requirements Memory initialization SMC and memory initialization sheet 1 SMC and memory initialization sheet 2 Where = denotes the appropriate chip select SMC and memory initialization sheet 3ARM DDI 0389B Signal Descriptions About the signals list Where Ahbc = AHB Configuration signalsName Type Source Description Destination Clocks and resetsTable A-1lists the clock and reset signals AHB signals Table A-2lists the AHB signalsWhere = 0 or C, where C = Configuration Table A-2 AHB signalsSMC memory interface signals Table A-3lists the SMC memory interface signalsTable A-4 SMC miscellaneous signals SMC miscellaneous signalsTable A-4lists the SMC miscellaneous signals Low-power interface Table A-5lists the low-power interface signalsConfiguration signal Table A-6lists the configuration signalTable A-6 Configuration signal Name Source Description Type DestinationScan chains Table A-7lists the scan chain signalsTable A-7 Scan chain signals ARM DDI 0389B Advanced High-performance Bus AHB Advanced Microcontroller Bus Architecture AmbaSee also Little-endian memory Advanced Peripheral Bus APBIncremented An 8-bit data itemData bus Multi-master operationDivisible by four See UnpredictableThat event resource is Unpredictable Other purposesHas been completed Written as 0 and read asRemapping ReservedGlossary-6