Rabbit 2000™ Microprocessor - UTN

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• Interrupts should be turned off (set the interrupt level to 3) whenever writes are occurring to theflash. Interrupts should not be turned back on until the write is complete -- an interrupt mayattempt to access a function in flash while the write is occurring and fail.• It should not return until the write operation is finished on the chip.• It should return a zero in HL if the operation was successful, a -3 if a timeout occurred duringthe wait, or a -4 if an attempt was made to write over the ID block.58 Rabbit 2000 Microprocessor
12. Troubleshooting Tips for NewRabbit-Based SystemsWhen a user designs a new microprocessor system around the Rabbit and carefully follows theRabbit design conventions, it is possible that the system will not boot up when Dynamic C is connectedto the programming connector. This can happen because of a design error or even becauseof a random hardware defect in the new system. A hardware procedure is available to make it easierto debug systematically in such a situation.A series of steps may be performed in order to diagnosis a problem that keeps Dynamic C frombooting.12.1 Initial ChecksPerform the following checks with the /RESET (pin 37) line tied to ground.• With a voltmeter check for the +5 V or other operating voltage on pins 3,28,53,78,92 and 42.Check for ground on pins 2, 27, 39, 52, 77 and 89.• With an oscilloscope check the 32.768 kHz oscillator on XTALA2 (pin 41). Make sure that it isoscillating and that the frequency is correct.• With an oscilloscope check the main system oscillator by observing the signal CLK (pin 1).With the reset held high this signal should have a frequency one eighth of the main crystal oroscillator frequency.12.2 Diagnostic Test #2This test goes through a series of steps repeatedly. The steps are:1. Apply the reset for approximately 1/4 second and then release the reset.2. In cold boot send the following sequence of triplet characters to serial port A via the programmingconnector.80 0E 20 // sets status pin low80 0E 30 // sets status pin high80 0E 20 // sets status pin low again3. Wait for approximately 1/4 second and then repeat starting at step #1.While the test is running, an oscilloscope can be used to observe the results. The scope can be triggeredby the reset line going high. It should be possible to observe the data characters being transmittedon the RXA pin of the processor or the programming connector. The status pin can also beobserved at the processor or programming connector. Each byte transmitted has 8 data bits precededby a start bit which is low and followed by a stop bit which is high (viewed at the processoror programming connector). The data bits are high for 1 and low for 0.Designer’s Handbook 59
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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 and 56: 9.1 Software Support for Low-Power
Page 57 and 58: 10. Memory PlanningThe following re
Page 59 and 60: 11. Flash MemoriesThe flash memorie
Page 61 and 62: Table 7. 32-Pin Flash Memories Supp
Page 63: The field flashXPC contains the XPC
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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