Rabbit 2000™ Microprocessor - UTN

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50 Rabbit 2000 Microprocessor
10. Memory PlanningThe following requirements should be considered when planning memory configuration for a Rabbitsystem.• The size of the code anticipated. Usually code size up to 512K is handled by one flash memorychip. Static data tables can be conveniently placed in the same space using the xdata andxstring declarations supported by Dynamic C, so the amount of space needed for static datacan be added to the amount of space needed for code. If you are writing a program from scratch,remember that 512K of code is equivalent to 25,000 to 50,000 C statements, and such a largeprogram can take years to write.• C programs vary in how much RAM will be required. Many programs can subsist on 32K ofRAM. Having more RAM on the system is convenient for debugging since debugging and programtesting generally operates more powerfully and faster when sufficient RAM is available tohold the program and data. For this reason, most Z-World controllers based on the Rabbit use adual footprint for RAM that can accommodate either a 32K x 8, which is in a 28-pin package, ora 128K x 8 or 512K x 8, which is in a 32-pin package. The base RAM is interfaced to /CS1 and/WE1, and /OE1.RAM is required for the following items:Root variables—maximum of 48K.Stack pages—rarely more than 20K.RAM for debugging convenience on prototype units—512K is usually enough toaccommodate programs.RAM for extended memory—such as data logging applications or communicationsapplications. The amount needed depends on application.10.1 Making a RAM-only board.Some Rabbit customers are designing boards that have only a single RAM chip and no flash memory.Although this is not generally recommended, it may be safe to use only a RAM chip as longas the board has a continuous power supply and is set up to be field-programmable via the Rabbitbootstrap mode.For example, a Rabbit board in a noncritical system such as a lawn sprinkler system may be monitoredfrom a remote location via the Internet or Ethernet, where the remote monitor has the abilityto reload the application program to the board. One way to achieve field programmability is withthe RabbitLink Network Gateway.There are certain hardware and software changes that are required to make this work which arediscussed here. Dynamic C starting with version 6.57 has the software files discussed here whichare necessary to make a RAM only board work.Designer’s Handbook 51
Page 1 and 2:
Rabbit 2000 MicroprocessorDesigner
Page 3 and 4:
Table of Contents1 Introduction ...
Page 5 and 6: Instructions Affected by the Wait S
Page 7 and 8: 1. IntroductionThis manual is inten
Page 9 and 10: 2. Rabbit Hardware DesignOverviewBe
Page 11 and 12: 2.3 Power ConsumptionWhen minimum p
Page 13 and 14: 3. Core Design and ComponentsCore d
Page 15 and 16: 3.2 Basic Memory DesignNormally /CS
Page 17 and 18: 3.3 PC Board Layout and Memory Line
Page 19 and 20: With a Rabbit-based system it is ea
Page 21 and 22: 3.4.2.3 High Frequency Oscillator C
Page 23 and 24: 3.4.2.4 Processor DecouplingThe int
Page 25 and 26: 4. How Dynamic C Cold Boots theTarg
Page 27 and 28: 4.2 Program Loading Process Overvie
Page 29 and 30: 5. Rabbit Memory OrganizationThe Ra
Page 31 and 32: 5.2.1 DefinitionsExtended Code: Ins
Page 33 and 34: 5.3.2 Paged Access in Extended Memo
Page 35 and 36: 6. The Rabbit BIOSWhen Dynamic C co
Page 37 and 38: 6.2 BIOS FlowchartThe following flo
Page 39 and 40: DATAORGBeginning logical address fo
Page 41 and 42: All origin statements must have a u
Page 43 and 44: 7. The System ID BlockThe BIOS supp
Page 45 and 46: 7.2 AccessThe BIOS will read the sy
Page 47 and 48: Table 4. The System ID Block (Conti
Page 49 and 50: 8. BIOS Support for ProgramCloningT
Page 51 and 52: 8.2.3 LED PatternsThe following tab
Page 53 and 54: 9. Low-Power Design and SupportTo g
Page 55: 9.1 Software Support for Low-Power
Page 59 and 60: 11. Flash MemoriesThe flash memorie
Page 61 and 62: Table 7. 32-Pin Flash Memories Supp
Page 63 and 64: The field flashXPC contains the XPC
Page 65 and 66: 12. Troubleshooting Tips for NewRab
Page 67 and 68: 80 24 80 //terminate bootstrap, sta
Page 69 and 70: Appendix A. Supported Rabbit 2000Ba
Page 71 and 72: Appendix B.Wait State BugB.1 Overvi
Page 73 and 74: If the atomic nature of the operati
Page 75 and 76: B.4 Enabling Wait StatesMemory wait
Page 77: Legal NoticeRabbit Semiconductor pr
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