Holtek HT48R30A-1 - Page 3

Special Function Registers .......................................................................................... 31
Indirect Addressing Registers - IAR, IAR0, IAR1 .................................................. 31
Memory Pointers - MP, MP0, MP1 ........................................................................ 31
Bank Pointer - BP .................................................................................................. 32
Accumulator - ACC................................................................................................ 33
Program Counter Low Register - PCL ......................................................................... 33
Look-up Table Registers - TBLP, TBHP, TBLH ..................................................... 33
Watchdog Timer Register - WDTS ........................................................................ 33
Status Register - STATUS ..................................................................................... 34
Interrupt Control Registers - INTC, INTC0, INTC1 ................................................ 35
Timer/Event Counter Registers ............................................................................ 35
Input/Output Ports and Control Registers ............................................................. 35
UART Registers - USR, UCR1, UCR2, TXR/RXR, BRG ...................................... 36
Input/Output Ports ........................................................................................................ 36
Pull-high Resistors ................................................................................................ 36
Port A Wake-up ..................................................................................................... 36
I/O Port Control Registers .................................................................................... 37
Pin-shared Functions ............................................................................................ 37
Programming Considerations ................................................................................ 40
Timer/Event Counters .................................................................................................. 41
Configuring the Timer/Event Counter Input Clock Source .................................... 41
Timer Registers - TMR, TMR0, TMR0L/TMR0H, TMR1L/TMR1H, TMR2 ............ 43
Timer Control Registers - TMRC, TMR0C, TMR1C, TMR2C ............................... 44
Configuring the Timer Mode .................................................................................. 47
Configuring the Event Counter Mode .................................................................... 47
Configuring the Pulse Width Measurement Mode ................................................ 48
Programmable Frequency Divider (PFD) and Buzzer Application ........................ 49
Prescaler ................................................................................................................ 50
I/O Interfacing ........................................................................................................ 50
Programming Considerations ................................................................................ 50
Timer Program Example ....................................................................................... 50
Interrupts ......................................................................................................................52
Interrupt Registers ................................................................................................. 52
Interrupt Priority ..................................................................................................... 56
External Interrupt ................................................................................................... 56
Timer/Event Counter Interrupt ............................................................................... 57
UART Interrupt ....................................................................................................... 57
Programming Considerations ................................................................................ 58
Reset and Initialization ................................................................................................. 58
Reset ..................................................................................................................... 58
Universal Asynchronous Receiver/Transmitter - UART .............................................. 66
UART Features ..................................................................................................... 66
UART External Pin Interfacing .............................................................................. 66
UART Data Transfer Scheme ................................................................................ 67
UART Status and Control Registers ...................................................................... 67
Baud Rate Generator ............................................................................................ 73
Setting Up and Controlling the UART .................................................................... 75
UART Transmitter ................................................................................................. 76
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I/O Type MCU