NEC switch - Page 11

User’s Manual U12978EJ3V0UD
11
3.3.4 Register addressing ......................................................................................................................50
3.4 Operand Address Addressing...................................................................................................51
3.4.1 Direct addressing ..........................................................................................................................51
3.4.2 Short direct addressing .................................................................................................................52
3.4.3 Special function register (SFR) addressing...................................................................................53
3.4.4 Register addressing ......................................................................................................................54
3.4.5 Register indirect addressing..........................................................................................................55
3.4.6 Based addressing .........................................................................................................................56
3.4.7 Stack addressing...........................................................................................................................56
CHAPTER 4 PORT FUNCTIONS...........................................................................................................57
4.1 Port Functions ............................................................................................................................57
4.2 Port Configuration......................................................................................................................59
4.2.1 Port 0.............................................................................................................................................60
4.2.2 Port 1.............................................................................................................................................61
4.2.3 Port 2.............................................................................................................................................62
4.2.4 Port 4.............................................................................................................................................68
4.3 Registers Controlling Port Function ........................................................................................69
4.4 Port Function Operation ............................................................................................................72
4.4.1 Writing to I/O port ..........................................................................................................................72
4.4.2 Reading from I/O port....................................................................................................................72
4.4.3 Arithmetic operation of I/O port .....................................................................................................72
CHAPTER 5 CLOCK GENERATOR......................................................................................................73
5.1 Clock Generator Functions .......................................................................................................73
5.2 Clock Generator Configuration.................................................................................................73
5.3 Register Controlling Clock Generator......................................................................................74
5.4 System Clock Oscillators ..........................................................................................................75
5.4.1 System clock oscillator..................................................................................................................75
5.4.2 Examples of incorrect resonator connection .................................................................................76
5.4.3 Frequency divider..........................................................................................................................77
5.5 Clock Generator Operation........................................................................................................77
5.6 Changing Setting of CPU Clock................................................................................................78
5.6.1 Time required for switching CPU clock .........................................................................................78
5.6.2 Switching CPU clock .....................................................................................................................78
CHAPTER 6 8-BIT TIMER/EVENT COUNTERS 00 AND 01 ............................................................79
6.1 Functions of 8-Bit Timer/Event Counters 00 and 01...............................................................79
6.2 Configuration of 8-Bit Timer/Event Counters 00 and 01.........................................................80
6.3 Registers Controlling 8-Bit Timer/Event Counters 00 and 01................................................82
6.4 Operation of 8-Bit Timer/Event Counters 00 and 01 ...............................................................85
6.4.1 Operation as interval timer ............................................................................................................85
6.4.2 Operation as external event counter (timer 01 only) .....................................................................87
6.4.3 Operation as square-wave output (timer 01 only) .........................................................................88
6.5 Notes on Using 8-Bit Timer/Event Counters 00 and 01 ..........................................................90