Quadrature Decoder | Jameco Electronics 2000, 3000 guide

7.14 Quadrature Decoder

The two-channel Quadrature Decoder accepts inputs, via Port F, from two external optical incremental encoder modules. Each channel of the Quadrature Decoder accepts an in- phase (I) and a quadrature-phase (Q) signal and provides 8-bit counters to track shaft rota- tion and provide interrupts when the count goes from 0x00 to 0xFF or from 0xFF to 0x00. The Quadrature Decoder contains digital filters on the inputs to prevent false counts. The Quadrature Decoder is clocked by the output of Timer A10.

Register Name	Mnemonic	I/O Address	R/W	Reset

Quad Decode Ctrl/Status Register	QDCSR	0x90	R/W	xxxxxxxx

Quad Decode Control Register	QDCR	0x91	W	00xx0000

Quad Decode Count 1 Register	QDC1R	0x94	R	xxxxxxxx

Quad Decode Count 2 Register	QDC2R	0x96	R	xxxxxxxx

Each Quadrature Decoder channel accepts inputs from either the upper nibble or lower nibble of Port F. The I signal is input on an odd-numbered port bit, while the Q signal is input on an even-numbered port bit. There is also a disable selection, which is guaranteed not to generate a count increment or decrement on either entering or exiting the disable state. The operation of the counter as a function of the I and Q inputs is shown below.

I input
Q input
Counter 00 01	02	03	04	05	06	07	08	07	06	05	04	03	02	01	00	FF
														Interrupt

The Quadrature decoders are clocked by the output of Timer A10, giving a maximum clock rate of one-half of the peripheral clock rate. The time constant of Timer A10 must be fast enough to sample the inputs properly. Both the I and Q inputs go through a digital fil- ter that rejects pulses shorter than two clock period wide. In addition, the clock rate must be High enough that transitions on the I and Q inputs are sampled in different clock cycles. The Input Capture may be used to measure the pulse width on the I inputs because they come from the odd-numbered port bits. The operation of the digital filter is shown below.

110	Rabbit 3000 Microprocessor

Image 119

Jameco Electronics 2000, 3000 manual Quadrature Decoder, Register Name Mnemonic Address Reset

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 Serial Ports Overview of On-Chip Peripherals and Features1 5 V Tolerant Inputs 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 Programming Port Separate Core and I/O Power PinsDesign Standards Spread Spectrum Clock 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 Manipulation of Boolean Variables How to Do It in Assembly Language-Tips and TricksZero HL in 4 Clocks Exchanges Not Directly Implemented 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 Nominal Ball Tolerance Ball Pitch Nominal Land Ball and Land Size DimensionsDesign Considerations All dimensions in mm Key Feature Recommendation BGA Package Outline Lqfp Tfbga Rabbit Pin DescriptionsRabbit Pin Descriptions Pin Pin Group Pin Name Direction Function Numbers 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 Symbol Parameter Test Conditions Min Typ Max Units DC Characteristics3 Volt DC Characteristics Symbol Parameter Maximum Rating 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 Rabbit Internal I/O Registers Default Values for all the Peripheral Control RegistersRegister Name Mnemonic Address Reset Grev PEB7R PWM0R Tbcsr Sdar Processor Identification Global ROM Configuration RegisterGlobal RAM Configuration Register Miscellaneous Functions Gcpu Rabbit Oscillators and ClocksGlobal CPU Register Global Revision Register Rabbit Gcsr Global Control/Status RegisterClock Select Field of Gcsr Global Control/Status Register Gcdr Recommended Delays Set In Gcdr for Clock DoublerClock Doubler Global Clock Double Register 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 Reg Name Reg Address Bits 7,6 Bits 5,4 Bits 3,2 Bits 1,0 Interrupt Vectors INT0 EIR,0x00/INT1 EIR,0x0816. Control Registers for External Interrupts 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 Iccsr 19. Input Capture Control/Status RegisterInput Capture Control/Status Register ICT1R 20. Input Capture Control Register21. Input Capture Trigger x Register Iccr 24. Input Capture MSB x Register 22. Input Capture Source x Register23. Input Capture LSB x Register Quadrature Decoder Rejected Qdcsr 25. Quadrature Decoder Control/Status RegisterQuad Decode Control/Status Register QDC1R 26. Quadrature Decoder Control Register27. Quadrature Decoder Count Register Qdcr 114 Rabbit 3000 Microprocessor Interface for Static Memory Chips Memory Interface and Mapping RAM RabbitData Lines Static Address Lines Memory Flash Processor Memory Mapping Unit Interface Memory Chips Memory Mapping OverviewMemory-Mapping Unit Segment Register Function 64KSegment Registers Segment Size Register Memory Interface Unit Memory Bank Control Register x MBxCR = 0x014 + Memory Bank Control Registers Mmidr Optional A16, A19 Inversions by Segment /CS1 EnableMMU Instruction/Data Register Mmidr = MMU Instruction/Data Register Memory Timing Control Register Memory Timing Control Register MTCR, adr =MMU Expanded Code Register Mecr Bdcr Allocation of Extended Code and DataBreakpoint/Debug Control Register BDCR, adr = 0x01C Breakpoint/Debug Control Register 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 Data Register Bit Functions Parallel Port aParallel Port a Registers Parallel Port B Register Bit Functions Parallel Port BParallel Port B Registers Parallel Port C Register Bit Functions Parallel Port CParallel Port C Registers Parallel Port D Registers Parallel Port D PD7 Bits 7 Bits 5 Bits 3 Bits 1 Parallel Port D Register functionsParallel Port D Control Register adr = 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 14. Parallel Port F Register Functions Parallel Port F13. Parallel Port F Registers 15. Parallel Port F Control Register adr = 0x03C Using Parallel Port a and Parallel Port F Summary Parallel Port a Parallel Port F 17. Parallel Port G Data Register Functions Parallel Port G16. Parallel Port G Registers Parallel Port G Control Register adr= 0x04C External I/O Timing with 1 wait state 10. I/O Bank Control RegistersWrite data Write strobe T1 Tw T2 Read data Read strobe Chip select strobe 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 Tacsr Timer a CapabilitiesTimer a Control and Status Register User’s Manual 153 Tapr Timer a Control RegisterTimer a Prescale Register Tacr Practical Use of Timer a Register Name Mnemonic Reset Address Timer BTimer B Registers Tbcr Timer B Control and Status RegisterTimer B Control Register Tbcsr 12. Timer B Count LSB Register Timer B Count MSB x Registers10. Timer B Count LSB x Registers 11. Timer B Count MSB Register Using Timer B 160 Rabbit 3000 Microprocessor Rabbit Serial Ports Serial Port SignalsSerial Port Signal Name Function Clka User’s Manual 163 Serial Port Register Layout Signals Shown at Microprocessor Tx Pin User’s Manual 165 Serial Port C Registers Serial Port RegistersSerial Port a Registers Serial Port B Registers Serial Port F Registers Serial Port D RegistersSerial Port E 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 Sbcr 14. Serial Port Control Register Ports a and BSacr Sdcr 15. Serial Port Control Register Ports C and DSccr Address = 0xE4 Sfcr 16. Serial Port Control Register Ports E and FSecr Address = 0xCC 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 External Clock Clocked Serial TimingClocked Serial Timing With Internal 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 Stop bit Parity, Extra Stop Bits with 7-Data-Bit CharactersParity, Extra Stop Bits with 8-Data-Bit Characters Stop bit Start bit Data bits 9th bit low Data Framing/Modbus Supporting 9th Bit Communication ProtocolsRabbit-Only Master/Slave Protocol 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 Register Mnemonic Internal Address External Address Hardware Design of Slave Port InterconnectionSlave Port Registers Slave Port Registers Bit Bits 6,5 Bit 3,2 Bits 1,0 Write Only Read Only Slave Port Control Register Spcr adr = Slave Port Status Register Spsr adr = Applications and Communications Protocols for SlavesSlave Applications 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 GCM1R Spread Spectrum Enable/Disable RegisterSpread Spectrum Mode Select GCM0R 214 Rabbit 3000 Microprocessor Memory Requirements at 3.3 V, -40C to +85C, Adr Bus 60 pF AC Timing SpecificationsMemory Access Time Access Enable Access MHz Normal Strong 30 pF 60 pF 90 pF No dbl/dbl Data and Clock Delays VDD ±10%, Temp, -40C-+85C maximumVDD CSx Time Delay Output Capacitance 30 pF 60 pF 90 pF Memory Read Time DelaysMemory Write Time Delays 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 Period Frequency Maximum Clock SpeedsMaximum Clock Speeds at 3.3 V Preliminary Conditions Commercial Ratings Industrial Ratings 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 Services Rabbit Bios and Virtual DriverBios Periodic Interrupt Bios AssumptionsWatchdog Timer Support Virtual Driver User’s Manual 239 240 Rabbit 3000 Microprocessor Other Rabbit Software Power Management Support Reading and Writing I/O Registers Using Assembly LanguageUsing Library Functions Atomic Instruction Shadow RegistersUpdating Shadow Registers Interrupt While Updating Registers Non-atomic Instructions Timer and Clock UsageWrite-only Registers Without Shadow Registers Format of the structure used is the following 246 Rabbit 3000 Microprocessor Summary Rabbit Instructions Flag Description Spreadsheet Conventions Rabbit Z180 Meaning Symbols 19.4 16-bit Indexed Loads and Stores Load Immediate DataLoad & Store to Immediate Address 19.3 8-bit Indexed Load and Store Register to Register Moves 19.5 16-bit Load and Store 20-bit Address 19.9 16-bit Arithmetic and Logical Ops Exchange InstructionsStack Manipulation Instructions 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 IL1T/IZ1T IL2T/IZ2T Discussion of Fixes and ImprovementsTable B-1. Summary of Rabbit 3000 Improvements and Fixes Rabbit Description 3000 3000A 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 Gcpu Grev Revision-Level ID RegisterTable B-5. Rabbit 3000 Revision Identification Information Processor Revision Package System/User Mode Wpcr Memory ProtectionTable B-6. Write Protect Control Register Write Protect Control Register Wplr Table B-7. Write Protect Low RegisterWrite Protect Low Register Wpsar Table B-8. Write Protect High RegisterTable B-9. Write Protect Segment x Register Wphr Wpsblr Table B-10. Write Protect Segment x Low RegisterWrite Protect Segment x Low Register Wpsalr Wpsbhr Table B-11. Write Protect Segment x High RegisterWrite Protect Segment x High Register Wpsahr Figure B-2. Simple Stack Protection Layout Stack Protection Table B-14. Stack High Limit Register Table B-12. Stack Limit Control RegisterTable B-13. Stack Low Limit Register Ramsr RAM Segment RelocationTable B-15. RAM Segment Register RAM Segment Register Wdtcr Secondary Watchdog TimerTable B-16. Watchdog Timer Control Register-Updated Table B-17. Secondary Watchdog Timer Register New UMA/UMS Opcodes New OpcodesTable B-18. New Rabbit 3000 Opcodes Instruction Bytes Clks Operation IOI/IOE Table B-19. Rabbit 3000 Revision Block Copy Opcode EffectsNew Block Copy Opcodes Source Destination Table B-20. MMU Instruction/Data Register Expanded I/O Memory Addressing Table B-21 Bank x Control Register External I/O Improvements Address = 0x000D Table B-22. Global Power Save Control RegisterShort Chip Select Timing for Writes Table B-24. Clock Select Field of Gcsr Clock Select and Power Save ModesTable B-23. Global Control/Status Register 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 PWM LSB 1 Register Table B-25. PWM LSB 0 RegisterTable B-26. PWM LSB 1 Register PWM LSB 0 Register Address = 0x008E Table B-27. PWM LSB 2 and 3 RegistersAddress = 0x008C QDC1HR Quadrature Decoder ImprovementsTable B-28. Quadrature Decoder Control Register Table B-29. Quadrature Decoder Count High Register User’s Manual 315 Serial Ports E/F Pins with Alternate Functions Table C-1. Differences Between System and User Modes Appendix C. SYSTEM/USER ModeSystem Mode User Mode Instruction Bytes Clk Operation Priv System/User Mode OpcodesTable C-2. New System/User Mode Opcodes 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