ST ST7 - Page 6

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Table of Contents
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5.3.1 ST72251 I/O Ports .....................................................94
5.3.2 ST72311 I/O Ports .....................................................96
5.4 WATCHDOG TIMER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
5.4.1 Aim of the watchdog ....................................................99
5.4.2 Watchdog Description ..................................................100
5.4.3 Using the Watchdog to protect an application ...............................103
5.5 16-BITTIMER ....................................................103
5.5.1 Timerclock ..........................................................104
5.5.2 Free running counter ..................................................105
5.5.2.1 Reading the free running counter . ...................................105
5.5.2.2 Resetting the free running counter ...................................106
5.5.2.3 TheTOFflag ....................................................107
5.5.3 Input capture operation .................................................108
5.5.4 Output compare operation . . ............................................110
5.5.5 One-pulsemode ......................................................113
5.5.6 Pulse-Width Modulation mode ...........................................115
5.6 ANALOGTODIGITALCONVERTER .................................117
5.6.1 Description ..........................................................117
5.6.2 UsingtheAnalogtoDigitalConverter......................................118
5.6.3 Theproblemoftheconverter'saccuracy ...................................119
5.6.4 Using the ADC to convert positive and negative voltages; increasing its resolution . .120
5.6.4.1 Measuring negative and positive voltages ..............................120
5.6.4.2 Increasingtheresolution ...........................................121
5.6.4.3 ApplicationExamples .............................................124
5.7 SERIALPERIPHERALINTERFACE ..................................125
5.8 SERIALCOMMUNICATIONINTERFACE ..............................128
5.8.1 Bit rate generator .....................................................128
5.8.2 Send and receive mechanism ...........................................129
5.8.3 Statusregister........................................................132
5.8.4 ControlRegister2.....................................................132
5.8.5 Using the Wake-Up feature in a multiprocessor system ........................133
5.8.6 Handling the interrupts .................................................133
6STMICROELECTRONICSPROGRAMMINGTOOLS ..........................135
6.1 ASSEMBLER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135
6.1.1 Anoverviewoftheassemblerfunction.....................................135
6.1.2 Instructioncoding .....................................................137
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