Current Consumption Mechanisms | Jameco Electronics 2000, 3000

16.6 Current Consumption Mechanisms

The following mechanisms contribute to the current consumption of the Rabbit 3000 while it is operating.

1.A current proportional to voltage and clock frequency that results from the charging of internal and external capacitances. At 3.3 V (see (2) below) approximately 57% of the current is due to charging and 43% is due to crossover current.

2.A crossover current that is proportional to clock frequency and to the overdrive voltage Vc = V × [(V/2) – 0.7], where V is the operating voltage of the Rabbit 3000. The cross- over current results from a brief short circuit when both the P and N transistors of a CMOS buffer are turned on at the same time. This component drops as the voltage drops, and becomes negligible at 1.4 V.

3.The current consumed by the built-in main oscillator when turned on. This current is also proportional to Vc, and is equal to 1 mA at 3.3 V.

4.The current drawn by the logic that is driven at the oscillator (crystal frequency). This is considered distinct because it varies with the crystal frequency, but is not reduced when the clock frequency is divided. This current becomes zero when the main oscillator is turned off, and is 2.5 mA at 3.3 V when the crystal frequency is 14.7 MHz. This current is divided between capacitive and crossover components in the same manner as the cur- rents in (1) and (2) above.

All of the above currents can be combined according to the following formula:

Itotal (mA) = 0.32 × V × f + 0.23 × Vc × f + 0.30 × Vc + 0.029 × V × fc + 0.025 × Vc × fc

where V = the operating voltage of the Rabbit 3000, Vc = V × [(V/2) – 0.7], fc = frequency of crystal oscillator in MHz, and f = clock frequency in MHz.

232	Rabbit 3000 Microprocessor

Image 241

Jameco Electronics 2000, 3000 manual Current Consumption Mechanisms

Contents

Page Rabbit 3000 Microprocessor Rabbit Semiconductor Trademarks Table of Contents Rabbit Internal I/O Registers Parallel Ports 129 Rabbit 3000 Clocks 209 Appendix B. Rabbit 3000 Revisions 273 Rabbit 3000 Microprocessor Introduction Features and Specifications Rabbit User’s Manual 1shows a block diagram of the Rabbit CPU Summary of Rabbit 3000 Advantages Differences Rabbit 3000 vs. Rabbit Feature Rabbit Serial ports with support for SDLC/HDLC IrDA Rabbit 3000 Design Features Rabbit 8-bit Processor vs. Other Processors 1 5 V Tolerant Inputs Overview of On-Chip Peripherals and FeaturesSerial Ports 4 32.768 kHz Oscillator Input System Clock Cascaded Output Registers for Parallel Ports D and E Parallel I/O Rabbit Slave Port Auxiliary I/O Bus Timers PWM Input Capture Channels Pulse Width Modulation Outputs Quadrature Encoder Inputs Design Standards Separate Core and I/O Power PinsSpread Spectrum Clock Programming Port Dynamic C Support for the Rabbit Standard Bios Rabbit 3000 Microprocessor Processor Registers Details on Rabbit Microprocessor Features Rabbit 3000 Microprocessor Addressing Memory Components Memory Mapping Example of Memory Mapping Operation 4shows a memory interface unit Extended Code Space Use of XPC Segment Separate I and D Space Extending Data Memory Xpc window stack Using the Stack Segment for Data Storage Data RAM Root Code Practical Memory Considerations User’s Manual Instruction Set Outline Load or Store Data from or to a Constant Address Load Immediate Data to a Register Other 8-bit loads and stores are the following Load or Store Data Using an Index Register Register Exchanges Register-to-Register Move 7 16-bit Arithmetic and Logical Ops Push and Pop Instructions Bool SBC instruction can also be used to perform a sign extension Input/Output Instructions Zero HL in 4 Clocks How to Do It in Assembly Language-Tips and TricksExchanges Not Directly Implemented Manipulation of Boolean Variables Comparisons of Integers HLB Atomic Moves from Memory to I/O Space Interrupt Priority Interrupt Structure Processor Priority Effect on Interrupts Effect of Processor Priorities on Interrupts Privileged Instructions, Critical Sections and Semaphores Multiple External Interrupting Devices Critical Sections Semaphores Using Bit B,HL Computed Long Calls and Jumps Precisely Timed Output Pulses Rabbit Capabilities Pulse Width Modulation to Reduce Relay Power Open-Drain Outputs Used for Key Scan Using Open-Drain Outputs for Key Scan Cold Boot Slave Port Slave Rabbit As a Protocol Uart PIN Assignments and Functions Pinout Lqfp Package Same pin dimensions apply along the x axis and the y axis Mechanical Dimensions and Land Pattern PC Board Land Pattern for Rabbit 3000 128-pin Lqfp Ball Grid Array Package C D E F G H J K L M Design Considerations All dimensions in mm Ball and Land Size DimensionsKey Feature Recommendation Nominal Ball Tolerance Ball Pitch Nominal Land BGA Package Outline Rabbit Pin Descriptions Rabbit Pin DescriptionsPin Pin Group Pin Name Direction Function Numbers Lqfp Tfbga Vddcore Bus Timing Read and Write Bus Timing Pins With Alternate Functions Description of Pins with Alternate Functions PF7 PWM3 AQD2A Parallel Port x Alternate Functions Control Bits Parallel Port x Alternate Functions 3 Volt DC Characteristics DC CharacteristicsSymbol Parameter Maximum Rating Symbol Parameter Test Conditions Min Typ Max Units I/O Buffer Sourcing and Sinking Limit Rabbit 3000 Microprocessor Rabbit Internal I/O Registers On-Chip Peripheral ISR Starting Address Rabbit 3000 Peripherals and Interrupt Service Vectors Register Name Mnemonic Address Reset Default Values for all the Peripheral Control RegistersRabbit Internal I/O Registers Grev PEB7R PWM0R Tbcsr Sdar Global RAM Configuration Register Global ROM Configuration RegisterMiscellaneous Functions Processor Identification Global CPU Register Rabbit Oscillators and ClocksGlobal Revision Register Gcpu Rabbit Clock Select Field of Gcsr Global Control/Status RegisterGlobal Control/Status Register Gcsr Clock Doubler Recommended Delays Set In Gcdr for Clock DoublerGlobal Clock Double Register Gcdr Effect of Clock Doubler User’s Manual Reduction in Peak Spectral Strength from Spectrum Spreader Clock Spectrum Spreader Chip Select Options for Low Power Address = 0x0D Global Power Save Control Register Short Chip Select Memory Read Global Output Control Register Gocr = 0x0E Output Pins CLK, STATUS, /WDTOUT, /BUFEN Time/Date Clock Real-Time Clock 11. Real-Time Clock Control Register Rtccr adr = 10. Real-Time Clock RTCxR Data Registers 12. Watchdog Timer Control Register Wdtcr adr = Watchdog Timer 13. Watchdog Timer Test Register Wdttr adr = System Reset Pin Name Direction Reset Low Post-Reset† Recognized by CPU 14. Rabbit 3000 Reset Sequence and State of I/O Pins Rabbit Interrupt Structure 15. Interrupts-Priority and Action to Clear Requests External Interrupt Line Logic External Interrupts 16. Control Registers for External Interrupts Interrupt Vectors INT0 EIR,0x00/INT1 EIR,0x08Reg Name Reg Address Bits 7,6 Bits 5,4 Bits 3,2 Bits 1,0 Bootstrap Operation 102 Rabbit 3000 Microprocessor Pulse Width LSBs 1st 2nd 3rd 4th Pulse Width Modulator 18. PWM MSB x Register 17. PWM LSB x Register Input Capture 106 Rabbit 3000 Microprocessor Input Capture Control/Status Register 19. Input Capture Control/Status RegisterIccsr 21. Input Capture Trigger x Register 20. Input Capture Control RegisterIccr ICT1R 23. Input Capture LSB x Register 22. Input Capture Source x Register24. Input Capture MSB x Register Quadrature Decoder Rejected Quad Decode Control/Status Register 25. Quadrature Decoder Control/Status RegisterQdcsr 27. Quadrature Decoder Count Register 26. Quadrature Decoder Control RegisterQdcr QDC1R 114 Rabbit 3000 Microprocessor Interface for Static Memory Chips Memory Interface and Mapping Data Lines Static Address Lines Memory Flash RabbitRAM Memory-Mapping Unit Memory Mapping OverviewProcessor Memory Mapping Unit Interface Memory Chips Segment Registers 64KSegment Size Register Segment Register Function Memory Interface Unit Memory Bank Control Register x MBxCR = 0x014 + Memory Bank Control Registers MMU Instruction/Data Register Mmidr = Optional A16, A19 Inversions by Segment /CS1 EnableMMU Instruction/Data Register Mmidr MMU Expanded Code Register Memory Timing Control Register MTCR, adr =Mecr Memory Timing Control Register Breakpoint/Debug Control Register BDCR, adr = 0x01C Allocation of Extended Code and DataBreakpoint/Debug Control Register Bdcr Instruction and Data Space Support RAM Use of Physical Memory Separate I & D Space Model How the Compiler Compiles to Memory 128 Rabbit 3000 Microprocessor Parallel Ports Parallel Port a Registers Parallel Port aParallel Port a Data Register Bit Functions Parallel Port B Registers Parallel Port BParallel Port B Register Bit Functions Parallel Port C Registers Parallel Port CParallel Port C Register Bit Functions Parallel Port D Registers Parallel Port D PD7 Parallel Port D Control Register adr = Parallel Port D Register functionsBits 7 Bits 5 Bits 3 Bits 1 136 Rabbit 3000 Microprocessor PE0 Parallel Port E 10. Parallel Port E Registers 12. Parallel Port E Control Register adr = 11. Parallel Port E Register functions 13. Parallel Port F Registers Parallel Port F14. Parallel Port F Register Functions 15. Parallel Port F Control Register adr = 0x03C Using Parallel Port a and Parallel Port F Summary Parallel Port a Parallel Port F 16. Parallel Port G Registers Parallel Port G17. Parallel Port G Data Register Functions Parallel Port G Control Register adr= 0x04C Write data Write strobe T1 Tw T2 10. I/O Bank Control RegistersRead data Read strobe Chip select strobe External I/O Timing with 1 wait state I/O Bank x Control Register Control Register Port E Address Pin A1513 Range External I/O Register Address Range and Pin Mapping 148 Rabbit 3000 Microprocessor Timers Reload Register Operation Timer a Timer a I/O Registers Timer a I/O Registers Timer a Control and Status Register Timer a CapabilitiesTacsr User’s Manual 153 Timer a Prescale Register Timer a Control RegisterTacr Tapr Practical Use of Timer a Timer B Registers Timer BRegister Name Mnemonic Reset Address Timer B Control Register Timer B Control and Status RegisterTbcsr Tbcr 10. Timer B Count LSB x Registers Timer B Count MSB x Registers11. Timer B Count MSB Register 12. Timer B Count LSB Register Using Timer B 160 Rabbit 3000 Microprocessor Serial Port Signal Name Function Serial Port SignalsRabbit Serial Ports Clka User’s Manual 163 Serial Port Register Layout Signals Shown at Microprocessor Tx Pin User’s Manual 165 Serial Port a Registers Serial Port RegistersSerial Port B Registers Serial Port C Registers Serial Port E Registers Serial Port D RegistersSerial Port F Registers Address Register All Ports Data Register All Ports 10. Long Stop Register All Ports 11. Status Register Asynchronous Mode Only All Ports 12. Status Register Clocked Serial Ports A-D only Bits Value Description Clocked serial mode only Bits Value Description Hdlc mode only 13. Status Register Hdlc Mode Ports E and F only Sacr 14. Serial Port Control Register Ports a and BSbcr Sccr 15. Serial Port Control Register Ports C and DAddress = 0xE4 Sdcr Secr 16. Serial Port Control Register Ports E and FAddress = 0xCC Sfcr 17. Extended Register Asynchronous Mode All Ports 18. Extended Register Clocked Serial Mode Ports A-D only 19. Extended Register Hdlc Mode Ports E and F only Transmitter IRQ Serial Port Interrupt Transmit Serial Data Timing Serial Port Synchronization Receive Serial Data Timing Clocked Serial Ports Clock Polarities Supported in Clocked Serial Mode User’s Manual 183 184 Rabbit 3000 Microprocessor Clocked Serial Timing With Internal Clock Clocked Serial TimingClocked Serial Timing with External Clock Valid Synchronous Communications on Ports E and F Last Byte Bit Pattern Valid Data Hits User’s Manual 189 190 Rabbit 3000 Microprocessor User’s Manual 191 Push AF IOI LD A,SCSR Serial Port Software Suggestions Transmitting Dummy Characters Controlling an RS-485 Driver and Receiver Transmitting and Detecting a Break Using a Serial Port to Generate a Periodic Interrupt Parity, Extra Stop Bits with 8-Data-Bit Characters Parity, Extra Stop Bits with 7-Data-Bit CharactersStop bit Start bit Data bits 9th bit low Stop bit Rabbit-Only Master/Slave Protocol Supporting 9th Bit Communication ProtocolsData Framing/Modbus User’s Manual 197 198 Rabbit 3000 Microprocessor SRD SCS Rabbit Slave Port Slave Port Read Cycle Following table explains the parameters used in Figure Symbol Parameter Minimum Maximum Slaveattn PB7 Typical Connection Slave Rabbit to Master Rabbit Slave Port Registers Hardware Design of Slave Port InterconnectionSlave Port Registers Register Mnemonic Internal Address External Address Bit Bits 6,5 Bit 3,2 Bits 1,0 Write Only Read Only Slave Port Control Register Spcr adr = Slave Applications Applications and Communications Protocols for SlavesSlave Port Status Register Spsr adr = Master-Slave Messaging Protocol 208 Rabbit 3000 Microprocessor Rabbit 3000 Main Oscillator Circuit Rabbit 3000 Clocks Low-Power Design EMI Control Using the Clock Spectrum Spreader Power Supply Connections and Board Layout Spread Spectrum Mode Select Spread Spectrum Enable/Disable RegisterGCM0R GCM1R 214 Rabbit 3000 Microprocessor Memory Access Time AC Timing SpecificationsAccess Enable Access MHz Memory Requirements at 3.3 V, -40C to +85C, Adr Bus 60 pF VDD Data and Clock Delays VDD ±10%, Temp, -40C-+85C maximumNormal Strong 30 pF 60 pF 90 pF No dbl/dbl CSx Memory Write Time Delays Memory Read Time DelaysTime Delay Output Capacitance 30 pF 60 pF 90 pF CLK A190 CSx WEx D70 Example Clock Doubler Max-Min Clock Low Times 222 Rabbit 3000 Microprocessor Bufen 16.2 I/O Access Time I/O Write Time Delays I/O Read Time Delays Further Discussion of Bus and Clock Timing Clock Doubler and Memory Timing Maximum Clock Speeds at 3.3 V Preliminary Maximum Clock SpeedsConditions Commercial Ratings Industrial Ratings Period Frequency External Oscillator Buffer User’s Manual 229 Power and Current Consumption Rabbit 3000 System Current vs. Frequency at 3.3 11. Sleepy Mode Current Consumption Current Consumption Mechanisms Sleepy Mode Current Consumption Memory Current Consumption Current is negligible for V 1.14 Battery-Backed Clock Current Consumption Voltage Current incl built-in buffer Reduced-Power External Main Oscillator Bios Rabbit Bios and Virtual DriverBios Services Watchdog Timer Support Bios AssumptionsVirtual Driver Periodic Interrupt User’s Manual 239 240 Rabbit 3000 Microprocessor Other Rabbit Software Power Management Support Using Library Functions Using Assembly LanguageReading and Writing I/O Registers Updating Shadow Registers Shadow RegistersInterrupt While Updating Registers Atomic Instruction Write-only Registers Without Shadow Registers Timer and Clock UsageNon-atomic Instructions Format of the structure used is the following 246 Rabbit 3000 Microprocessor Summary Rabbit Instructions Flag Description Spreadsheet Conventions Rabbit Z180 Meaning Symbols Load & Store to Immediate Address Load Immediate Data19.3 8-bit Indexed Load and Store 19.4 16-bit Indexed Loads and Stores Register to Register Moves 19.5 16-bit Load and Store 20-bit Address Stack Manipulation Instructions Exchange Instructions19.9 16-bit Arithmetic and Logical Ops ADD A,HL 19.10 8-bit Arithmetic and Logical Ops 19.12 8-bit Increment and Decrement 19.11 8-bit Bit Set, Reset and Test 19.14 8-bit Shifts and Rotates 19.13 8-bit Fast a Register Operations Block Move Instructions Instruction Prefixes Miscellaneous Instructions Control Instructions Jumps and Calls Following instructions are privileged Privileged Instructions Differences Rabbit VS. Z80/Z180 Instructions Z80/Z180 Instructions Dropped Rabbit Instructions to Use Flag Register Key IOI and IOE I Column Symbol Key Rabbit Z180 Meaning Z V C EX AF,AF LD A,BC LDP HL,IX RRA 268 Rabbit 3000 Microprocessor Programming Port PIN Assignments Appendix A. the Rabbit Programming Port Alternate Programming Port Use of the Programming Port as a Diagnostic/Setup Port Suggested Rabbit Crystal Frequencies Non-Stock Crystals Appendix B. Rabbit 3000 Revisions 274 Rabbit 3000 Microprocessor User’s Manual 275 Table B-1. Summary of Rabbit 3000 Improvements and Fixes Discussion of Fixes and ImprovementsRabbit Description 3000 3000A IL1T/IZ1T IL2T/IZ2T Rabbit Internal I/O Registers Table B-2. Reset State of New Rabbit 3000A I/O Registers Iuer Rabbit Register Name Mnemonic 3000 3000A Address Reset On-Chip Peripheral Address Range ISR Starting Address Peripheral and ISR Address User’s Manual 281 Table B-5. Rabbit 3000 Revision Identification Information Revision-Level ID RegisterProcessor Revision Package Gcpu Grev System/User Mode Table B-6. Write Protect Control Register Memory ProtectionWrite Protect Control Register Wpcr Write Protect Low Register Table B-7. Write Protect Low RegisterWplr Table B-9. Write Protect Segment x Register Table B-8. Write Protect High RegisterWphr Wpsar Write Protect Segment x Low Register Table B-10. Write Protect Segment x Low RegisterWpsalr Wpsblr Write Protect Segment x High Register Table B-11. Write Protect Segment x High RegisterWpsahr Wpsbhr Figure B-2. Simple Stack Protection Layout Stack Protection Table B-13. Stack Low Limit Register Table B-12. Stack Limit Control RegisterTable B-14. Stack High Limit Register Table B-15. RAM Segment Register RAM Segment RelocationRAM Segment Register Ramsr Table B-16. Watchdog Timer Control Register-Updated Secondary Watchdog TimerTable B-17. Secondary Watchdog Timer Register Wdtcr Table B-18. New Rabbit 3000 Opcodes New OpcodesInstruction Bytes Clks Operation New UMA/UMS Opcodes New Block Copy Opcodes Table B-19. Rabbit 3000 Revision Block Copy Opcode EffectsSource Destination IOI/IOE Table B-20. MMU Instruction/Data Register Expanded I/O Memory Addressing Table B-21 Bank x Control Register External I/O Improvements Short Chip Select Timing for Writes Table B-22. Global Power Save Control RegisterAddress = 0x000D Table B-23. Global Control/Status Register Clock Select and Power Save ModesTable B-24. Clock Select Field of Gcsr Figure B-3. Short Chip Select Timing CLK/8, Read Operation Short Chip Select Timing Figure B-4. Short Chip Select Timing CLK/6, Read Operation Figure B-6. Short Chip Select Timing CLK/2, Read Operation Figure B-7. Short Chip Select Timing 2 kHz, Read Operation Figure B-9. Short Chip Select Timing 8 kHz, Read Operation Figure B-11. Short Chip Select Timing 32 kHz, Read Operation Figure B-12. Short Chip Select Timing CLK/8, Write Operation Figure B-13. Short Chip Select Timing CLK/6, Write Operation Figure B-15. Short Chip Select Timing CLK/2, Write Operation Figure B-16. Short Chip Select Timing 2 kHz, Write Operation Figure B-18. Short Chip Select Timing 8 kHz, Write Operation 310 Rabbit 3000 Microprocessor Figure B-21. PWM Interrupt and Output Timing Pulse Width Modulator Improvements Table B-26. PWM LSB 1 Register Table B-25. PWM LSB 0 RegisterPWM LSB 0 Register PWM LSB 1 Register Address = 0x008C Table B-27. PWM LSB 2 and 3 RegistersAddress = 0x008E Table B-28. Quadrature Decoder Control Register Quadrature Decoder ImprovementsTable B-29. Quadrature Decoder Count High Register QDC1HR User’s Manual 315 Serial Ports E/F Pins with Alternate Functions System Mode User Mode Appendix C. SYSTEM/USER ModeTable C-1. Differences Between System and User Modes Table C-2. New System/User Mode Opcodes System/User Mode OpcodesInstruction Bytes Clk Operation Priv Table C-3. System/User Mode I/O Registers System/User Mode Registers Register Name Mnemonic Address Table C-4. I/O Addresses Inaccessible in User Mode Interrupts Figure C-1. Interrupt Handing in System/User Mode Peripheral Interrupt Prioritization Table C-5. Interrupts-Priority and Action to Clear Requests Memory Protection Only Using the System/User Mode Figure C-3. System/User Mode Setup for Mixed Operation Mixed System/User Mode Operation Complete Operating System Figure C-4. System/User Mode Setup for Operating System Table D-1 Rabbit 3000A Internal I/O Registers Appendix D. Rabbit 3000A Internal I/O Registers Table D-1. Rabbit 3000A Internal I/O Registers 0x03C0 00000000 Serial Port E User Enable Register 0x006A Xxxxxxxx Port D Bit 3 Register 0x0082 00000000 Bank 3 Control Register 0x0098 Xx000000 Interrupt 1 Control Register 0x00D1 Xxxxxxxx Serial Port B Long Stop Register 334 Rabbit 3000 Microprocessor User’s Manual 335 Page Numerics Index Memory A16, A19 inversions /CS1 PWL2R, PWL3R 200