80C186EC/80C188EC Microprocessor User's Manual

CONTENTS
11.4 SERIAL COMMUNICATIONS UNIT INTERRUPTS .................................................. 11-21
11.5 SERIAL PORT EXAMPLES....................................................................................... 11-21
11.5.1 Asynchronous Mode Example ..............................................................................11-21
11.5.2 Mode 0 Example ...................................................................................................11-23
11.5.3 Master/Slave Example ..........................................................................................11-24
CHAPTER 12
WATCHDOG TIMER UNIT
12.1 FUNCTIONAL OVERVIEW.......................................................................................... 12-1
12.2 USING THE WATCHDOG TIMER AS A SYSTEM WATCHDOG ............................... 12-1
12.2.1 Reloading the Watchdog Timer Down Counter .......................................................12-3
12.2.2 Watchdog Timer Reload Value ...............................................................................12-4
12.2.3 Initialization .............................................................................................................12-5
12.3 USING THE WATCHDOG TIMER AS A GENERAL-PURPOSE TIMER .................... 12-6
12.4 DISABLING THE WATCHDOG TIMER....................................................................... 12-6
12.5 WATCHDOG TIMER REGISTERS.............................................................................. 12-8
12.6 INITIALIZATION EXAMPLE....................................................................................... 12-12
CHAPTER 13
INPUT/OUTPUT PORTS
13.1 FUNCTIONAL OVERVIEW.......................................................................................... 13-1
13.1.1 Bidirectional Port .....................................................................................................13-1
13.1.2 Output Port ..............................................................................................................13-3
13.1.3 Open-Drain Bidirectional Port .................................................................................13-3
13.1.4 Port Pin Organization ..............................................................................................13-3
13.1.4.1 Port 1 Organization .......................................................................................13-6
13.1.4.2 Port 2 Organization .......................................................................................13-6
13.1.4.3 Port 3 Organization .......................................................................................13-7
13.2 PROGRAMMING THE I/O PORT UNIT....................................................................... 13-7
13.2.1 Port Control Register ..............................................................................................13-7
13.2.2 Port Direction Register ............................................................................................13-8
13.2.3 Port Data Latch Register .........................................................................................13-9
13.2.4 Port Pin State Register .........................................................................................13-10
13.2.5 Initializing the I/O Ports .........................................................................................13-11
13.3 PROGRAMMING EXAMPLE..................................................................................... 13-12
CHAPTER 14
MATH COPROCESSING
14.1 OVERVIEW OF MATH COPROCESSING.................................................................. 14-1
14.2 AVAILABILITY OF MATH COPROCESSING.............................................................. 14-1
14.3 THE 80C187 MATH COPROCESSOR........................................................................ 14-2
14.3.1 80C187 Instruction Set ...........................................................................................14-2
14.3.1.1 Data Transfer Instructions .............................................................................14-3
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