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GPTRl Modular Microcontroller Family GENERAL PURPOSE TIMER REFERENCE MANUAL @ MOTOROLA I" FUNCTIONAL OVERVIEW E SIGNAL DESCRIPTIONS E COMPARE/CAPTURE UNIT I PULSE ACCUMULATOR E PRESCALER E PULSE WIDTH MODULATION UNIT I INTERRUPTS GENERAL PURPOSE I/O SPECIAL MODES APPLICATIONS AND EXAMPLES ELECTRICAL CHARACTERISTICS MEMORY MAP AND REGISTERS PIN SUMMARY INDEX FUNCTIONAL OVERVIEW SIGNAL DESCRIPTIONS COMPARE/CAPTURE UNIT PULSE ACCUMULATOR PRESCALER PULSE WIDTH MODULATION UNIT INTERRUPTS GENERAL PURPOSE I/O SPECIAL MODES APPLICATIONS AND EXAMPLES ELECTRICAL CHARACTERISTICS MEMORY MAP AND REGISTERS PIN SUMMARY INDEX GPT GENERAL PURPOSE TIMER REFERENCE MANUAL Motorola reseNes the right to make changes without further notice to any products herein to improve reliability, function or design. Motorola does not assume any liability arising out of the application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that Motorola ® was negligent regarding the design or manufacture of the part. Motorola and are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer. © MOTOROLA INC., 1991 PREFACE The General-Purpose Timer (GPT) is an integral module of Motorola's family of modular microcontrollers. The GPT Reference Manual describes the capabilities, operation, and functions of the GPT. This reference manual is organized as follows: Section 1 Functional Overview Section 2 Signal Descriptions Section 3 Compare/Capture Unit Section 4 Pulse Accumulator Section 5 Prescaler Section 6 Pulse-Width Modulation Unit Section 7 Interrupts Section 8 General-Purpose I/O Section 9 Special Modes Section 10 Applications and Examples Section 11 Electrical Characteristics Appendix A Appendix B Index GPT REFERENCE MANUAL MOTOROLA iii MOTOROLA GPT REFERENCE MANUAL iv TABLE OF CONTENTS Paragraph Page Number Title Number Section 1 Functional Overview 1. 1 Features ................................................................................................. 1-3 1.2 Input Capture (IC) Concepts .................................................................. 1-4 1.3 Output Compare (OC) Concepts ........................................................... 1-5 1.4 Pulse Accumulator Input (PAl) Concepts ............................................... 1-6 1.5 Pulse-Width Modulation (PWM) Concepts ............................................. 1-6 Section 2 Signal Descriptions 2.1 Signal Groups ........................................................................................ 2-1 2.2 Input Capture Pins (IC1-IC3) ................................................................. 2-1 2.3 Input Capture/Output Compare Pin (IC4/0C5) ...................................... 2-2 2.4 Output Compare Pins (OC1-OC4) ........................................................ 2-2 2.5 Pulse Accumulator Input (PAl) Pin ........................................................ 2-2 2.6 Pulse-Width Modulation (PWMA, PWMB) ............................................. 2-2 2.7 Auxiliary Timer Clock Input (PCLK) ........................................................ 2-3 Section 3 Compare/Capture Unit 3.1 Timer Counter ........................................................................................ 3-1 3.2 Input Capture Functions ......................................................................... 3-3 3.2.1 Input Capture Registers (TIC1-3) .................................................. 3-4 3.2.2 Input Capture 4/0utput Compare Register (TI405) ....................... 3-5 3.2.3 Timer Control Register 2 (TCTL2) ................................................. 3-5 3.3 Output Compare Functions .................................................................... 3-6 3.3.1 Timer Control Register 1 (TCTL 1) ................................................. 3-7 3.3.2 Output Compare Registers (TOC1-4) (TI405) .............................. 3-8 3.3.3 Output Compare 1 (OC1) .............................................................. 3-9 3.3.4 Timer Compare Force Register (CFORC) ................................... 3-10 3.4 Input Capture4/0utput Compare Function 5 (IC4/0C5) ...................... 3-11 GPT REFERENCE MANUAL MOTOROLA v TABLE OF CONTENTS (Continued) Paragraph Page Number Title Number Section 4 Pulse Accumulator 4.1 Pulse Accumulator ................................................................................. 4-1 4.1.1 Pulse Accumulator Register/Pulse Accumulator Counter (PACTUPACNT) ............................................................................ 4-3 Section 5 Prescaler 5.1 Prescaler ................................................................................................ 5-1 Section 6 Pulse-Width Modulation Unit 6.1 Counter .................................................................................................. 7-1 6.2 PWM Function ....................................................................................... 7-4 6.3 PWM Registers ...................................................................................... 7-4 6.3.1 PWM Control Register (PWMC) .................................................... 7-4 6.3.2 PWM Registers NB (PWMA/PWMB) ............................................ 7-6 6.3.3 PWM Buffer Registers NB (PWMBUFNPWMBUFB) ................... 7-7 6.4 PWM Pins .............................................................................................. 7-7 Section 7 Interrupts 7.1 Interrupts ................................................................................................ 7-1 7.1.1 GPT Interrupt Configuration Register (ICR) ................................... 7-3 7.1.2 Interrupt Status Flags .................................................................... 7-4 7.1.2.1 Timer Interrupt Flag Registers 1-2 (TFLG1ITFLG2) ........... 7-5 7.1.3 Enabling Interrupts ......................................................................... 7-6 7.1.3.1 Timer Interrupt Mask Registers 1-2 (TMSK1 ITMSK2) ....... 7-6 Section 8 General-Purpose I/O 8.1 General Purpose I/O .............................................................................. 8-1 8.1.1 Uni-Directionall/O ................................................... , ...................... 8-2 MOTOROLA GPT REFERENCE MANUAL vi TABLE OF CONTENTS (Concluded) Paragraph Page Number Title Number Section 9 Special Modes 9.1 Test Mode .............................................................................................. 9-1 9.2 Stop Mode .............................................................................................. 9-1 9.3 Freeze Mode ......... '" .............................................................................. 9-2 9.4 Single Step Mode (STOPP) ................................................................... 9-3 9.5 Supervisor Mode .................................................................................... 9-3 Section 10 Applications and Examples 7.1 Electronic Motor Speed Control ........................................................... 10-1 7.2 Engine Spark and Fuel Timing ............................................................. 10-2 7.3 Software Examples .............................................................................. 10-5 Section 11 Electrical Characteristics 8.1 AC Characteristics ............................................................................... 11-1 8.2 Timing Specifications ........................................................................... 11-1 Appendix A A.1 GPT Register Map ................................................................................ A-1 A.2 GPT Registers ...................................................................................... A-2 Appendix B B.1 GPT Pin Summary ................................................................................ B-1 Index GPT REFERENCE MANUAL MOTOROLA vii