uPD789871 Subseries 8-Bit Single-Chip Microcontrollers PUM

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3.4.1 Direct addressing ..................................................................................................................... 48
3.4.2 Short direct addressing ............................................................................................................ 49
3.4.3 Special function register (SFR) addressing ............................................................................ 50
3.4.4 Register addressing ................................................................................................................. 51
3.4.5 Register indirect addressing .................................................................................................... 52
3.4.6 Based addressing ..................................................................................................................... 53
3.4.7 Stack addressing ...................................................................................................................... 53
CHAPTER 4 PORT FUNCTIONS ..................................................................................................... 54
4.1 Functions of Ports ............................................................................................................. 54
4.2 Port Configuration ............................................................................................................. 56
4.2.1 Port 0 ........................................................................................................................................ 56
4.2.2 Port 1 ........................................................................................................................................ 57
4.2.3 Port 2 ........................................................................................................................................ 58
4.2.4 Port 8 ........................................................................................................................................ 61
4.2.5 Port 9 ........................................................................................................................................ 62
4.3 Port Function Control Registers...................................................................................... 63
4.4 Operation of Port Functions ............................................................................................. 65
4.4.1 Writing to I/O port ..................................................................................................................... 65
4.4.2 Reading from I/O port .............................................................................................................. 65
4.4.3 Arithmetic operation of I/O port................................................................................................ 65
CHAPTER 5 CLOCK GENERATOR ................................................................................................ 66
5.1 Clock Generator Functions .............................................................................................. 66
5.2 Clock Generator Configuration ........................................................................................ 66
5.3 Register Controlling Clock Generator ............................................................................ 68
5.4 System Clock Oscillators ................................................................................................. 70
5.4.1 Main system clock oscillator .................................................................................................... 70
5.4.2 Subsystem clock oscillator ........................................................................................................ 70
5.4.3 Frequency divider ..................................................................................................................... 72
5.4.4 When no subsystem clock is used .......................................................................................... 72
5.5 Clock Generator Operation ............................................................................................... 73
5.6 Changing Setting of System Clock and CPU Clock...................................................... 74
5.6.1 Time required for switching between system clock and CPU clock ...................................... 74
5.6.2 Switching between system clock and CPU clock ................................................................... 75
CHAPTER 6 8-BIT REMOTE CONTROL TIMER ............................................................................. 76
6.1 8-Bit Remote Control Timer Functions ........................................................................... 76
6.2 8-Bit Remote Control Timer Configuration .................................................................... 76
6.3 Registers Controlling 8-Bit Remote Control Timer ....................................................... 77
6.4 Operation of 8-Bit Remote Control Timer....................................................................... 78
CHAPTER 7 8-BIT TIMER ................................................................................................................ 80
7.1 8-Bit Timer Functions ........................................................................................................ 80
7.2 8-Bit Timer Configuration ................................................................................................. 81
7.3 Registers Controlling 8-Bit Timer .................................................................................... 83
7.4 8-Bit Timer Operation ........................................................................................................ 85
7.4.1 Operation as interval timer....................................................................................................... 85
Preliminary User’s Manual U14938EJ1V0UM