SMC Networks AHB SRAM/NOR, PL241 manual Clock domain operation, Ahbc memory map

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Functional Overview

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Figure 2-6 AHBC memory map

The other fourteen 4KB regions are read as zero. The lower 16 bits of the AHB address decode the memory controller that is being used. An external AHB decoder determines where in the system memory map, this 64KB region is located. See About the programmer’s model on page 3-2for information on the internal memory controller configuration registers. The configuration port of the internal memory controller is APB, so only word reads and writes are supported.

2.3.3Clock domain operation

The memory controller supports two clock domains:

•the AHB clock domain

•the static memory clock domain.

The hclk input drives the AHB clock domain. This clock drives the AHB interfaces and bus matrix. The static memory controller has a separate clock input in this domain. This is called smc_aclk. This signal is separated to enable the clock to be stopped independently of hclk for low-power operation, see Low-power interface operation on page 2-12.These two clocks must always be driven from the same clock source. The input signal hresetn resets this clock domain.

The static memory clock domain controls the memory interface logic of the SMC. The input signal smc_mclk0 and its inverse smc_mclk0n drive this domain. Each external static memory chip is driven by a gated smc_mclk0 signal, these are called smc_clk_out_0[3:0]. Clocks are only driven out to chips that require them. The static memory interface has a fed back clock input, smc_fbclk_in_0, to help with clock skews on the external pads.

The memory controller supports many different options for clocking the different domains:

ARM DDI 0389B

Copyright © 2006 ARM Limited. All rights reserved.

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Contents PrimeCell AHB SRAM/NOR Memory Controller PL241 Technical Reference Manual PrimeCell AHB SRAM/NOR Memory Controller PL241Copyright 2006 ARM Limited. All rights reserved 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 Feedback on PrefaceIntended audience Using this manualAbout this manual Product revision statusTypographical ConventionsBold Signals Timing diagramsFurther reading NumberingARM publications Feedback on this product FeedbackFeedback on this manual Introduction This section describes About the AHB MCSMC on AHB to APB bridge AHB interface3 SMC Low-power interfacesClock domains Intel W18 series NOR FLASH, for example 28f128W18td Supported devicesIntroduction Copyright 2006 ARM Limited. All rights reserved Functional Overview This section is divided into Functional descriptionStatic memory clock domain Smcmreset0nLow-power interface AHB clock domainInterrupts on SMCMain blocks of the SMC are Format onMemory manager SMC interfaceAPB slave interface FormatInterrupts Pad interfaceAHB interface operation Functional operationAHB fixed burst types Undefined length Incr bursts Bufferable bit of the Hprot signalBroken bursts Read after write hazard detection buffer AHB response signalsLocked transfers AHB to APB bridge operation Big-endian 32-bit modeRemoval of AHB error response logic Registered HwdataAhbc memory map Clock domain operationStatic memory clocking options Low-power interface operationStatic memory clocking options 1lists the static memory clocking optionsAn active output Domaincactive Where Domain is ahb or smcAccepting requests Operating states SMC functional operationSMC states are as follows Clocking Clocking and resetsResets Smcagtm0sync Miscellaneous signalsSmcuserconfig70 Smcuserstatus70Format block APB slave interface operationHazard handling Sram memory accesses Memory burst length Chip configuration registers Low-power operationMemory manager operation 11 Chip configuration registers Device pin mechanism Direct commandsSoftware mechanism 12 Device pin mechanism 13 Software mechanism Interrupts operation Sram timing tables and diagramsMemory interface operation Asynchronous read Sram cycles register settings Asynchronous read opmode chip register settings14 Asynchronous read 4and -5list the smcopmode00-3 and Sram Register settingsAsynchronous write opmode chip register settings 6and -7list the smcopmode00-3 and Sram Register settingsAsynchronous write Sram cycles register settings 10and -11list the smcopmode00-3 and Sram Register settings 8and -9list the smcopmode00-3 and Sram Register settings10 Page read opmode chip register settings 12 Synchronous burst read opmode chip register settings 12and -13list the smcopmode00-3 and Sram Register settings13 Synchronous burst read Sram cycles register settings 19 Synchronous burst read 20 Synchronous burst read in multiplexed-mode 14and -15list the smcopmode00-3 and Sram Register settings16 Synchronous burst write opmode chip register settings 16and -17list the smcopmode00-3 and Sram Register settings17 Synchronous burst write Sram cycles register settings 22 Synchronous burst write in multiplexed-mode 18and -19list the smcopmode00-3 and Sram Register settingsB0100 B0110 B001 20and -21list the smcopmode00-3 and Sram Register settingsTCEOE is only required if wait is asserted when oen goes LOW TWC = ARM DDI 0389B Programmer’s Model About the programmer’s model Register summary 2shows the SMC configuration register map1lists the SMC Registers Name Base offset Type Reset value DescriptionRegister summary 2lists the register bit assignments Register descriptionsThis section describes the SMC registers SMC Memory Controller Status Register at3lists the register bit assignments SMC Memory Interface Configuration Register atBits Name Function Smcmemccfgset Register bit assignments SMC Set Configuration Register atSmcmemccfgclr Register bit assignments Bits Name Function SMC Clear Configuration Register at 0x100C4lists the register bit assignments 5lists the register bit assignments6lists the register bit assignments SMC Direct Command Register atSmcdirectcmd Register bit assignments Lists the register bit assignments SMC Set Cycles Register at12 smcsetopmode Register bit assignments SMC Set Opmode Register at8lists the register bit assignments Memory width mw field Smcsetopmode Register bit assignmentsSMC Sram Cycles Registers 0-3 at 0x1100, 0x1120, 0x1140 SMC Refresh Period 0 Register atSmcrefreshperiod0 Register bit assignments SMC Opmode Registers 0-3 at 0x1104, 0x1124, 0x1144 10lists the register bit assignments11lists the register bit assignments 12 smcuserstatus Register bit assignments SMC User Status Register at12lists the register bit assignments 11 smcopmode Register bit assignmentsBits Name Description SMC User Configuration Register at13 smcuserconfig Register bit assignments 13 lists the register bit assignmentsSMC Peripheral Identification Register Following section describe the smcperiphid Registers15 smcperiphid0 Register bit assignments Bits Name Function 17 smcperiphid2 Register bit assignments Bits Name Function 16 smcperiphid1 Register bit assignments Bits Name Function19shows the register bit assignments SMC PrimeCell Identification Registers 0-3 at 0x1FF0-0x1FFC20 smcpcellid0 Register bit assignments Bits Name Function These registers cannot be read in the Reset stateFollowing sections describe the smcpcellid Registers SMC PrimeCell Identification Register23 smcpcellid3 Register bit assignments Bits Name Function 22 smcpcellid2 Register bit assignments Bits Name FunctionProgrammer’s Model for Test Lists the SMC integration test registers Test registers are provided for integration testingSMC Integration Configuration Register at 0x1E00 SMC integration test registersSmcintinputs Register bit assignments Bits Name Function Integration Inputs Register at 0x1E04State Integration Outputs Register at 0x1E08Device Driver Requirements Memory initialization SMC and memory initialization sheet 1 SMC and memory initialization sheet 2 SMC and memory initialization sheet 3 Where = denotes the appropriate chip selectARM DDI 0389B Signal Descriptions Where Ahbc = AHB Configuration signals About the signals listTable A-1lists the clock and reset signals Clocks and resetsName Type Source Description Destination Table A-2 AHB signals AHB signalsTable A-2lists the AHB signals Where = 0 or C, where C = ConfigurationTable A-3lists the SMC memory interface signals SMC memory interface signalsTable A-4lists the SMC miscellaneous signals SMC miscellaneous signalsTable A-4 SMC miscellaneous signals Table A-5lists the low-power interface signals Low-power interfaceName Source Description Type Destination Configuration signalTable A-6lists the configuration signal Table A-6 Configuration signalTable A-7 Scan chain signals Table A-7lists the scan chain signalsScan chains ARM DDI 0389B Advanced Microcontroller Bus Architecture Amba Advanced High-performance Bus AHBAdvanced Peripheral Bus APB See also Little-endian memoryMulti-master operation IncrementedAn 8-bit data item Data busOther purposes Divisible by fourSee Unpredictable That event resource is UnpredictableReserved Has been completedWritten as 0 and read as RemappingGlossary-6