8 comparator assembler block

Microcontrollers COMPARATOR MODULE Microcontrollers COMPARATOR MODULE • The comparator module contains two analog compara• tors • The inputs to the comparators are multiplexed with I/O port pins RA0 through RA3, while the outputs are multiplexed to pins RA4 and RA5 • The on-chip voltage reference can also be an input to the comparators Microcontrollers COMPARATOR I/O OPERATING MODES Microcontrollers COMPARATOR I/O OPERATING MODES Microcontrollers SINGLE COMPARATOR COMPARATOR VOLTAGE REFERENCE MODULE Microcontrollers COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM Microcontrollers COMPARATOR VOLTAGE REFERENCE MODULE Microcontrollers COMPARATOR VOLTAGE REFERENCE MODULE #include #fuses XT,WDT,NOPROTECT #use delay(clock=4000000) #use rs232(baud=9600, xmit=PIN_D0, rcv=PIN_D1) main() { delay_ms(1000); putc(254); putc(1); delay_ms(10); printf("Voltage test"); delay_ms(1000); setup_comparator(A0_VR_A1_VR); setup_vref(VREF_HIGH|15); while(TRUE) { putc(254); putc(1); delay_ms(10); if(C1OUT){ printf("Below 3.6 V."); delay_ms(1000); } else{ printf("Above 3.6 V."); delay_ms(1000); } } } Microcontrollers PIC16 C Assembler Routines ● Reasons for using assembly language ● Insertion of assembler sequence ● Overview of assembly language Reasons for using assembly language Microcontrollers • The default programming language of any microprocessor or microcontroller is its own assembly language • Assembly language is the first-level abstraction from machine code, where each instruction is represented by a corresponding text mnemonic • When compiled, a C program is converted into assembler, then to machine code 10 Microcontrollers C Code Fragment for Pulse Output Loop #include "16F877a.h" // MCU header file void main() // Main block start { while(1) { output_high(PIN_D0); output_low(PIN_D0); } } 11 Microcontrollers Disassembled Code for Pulse Output Loop 12 Assembler Block Microcontrollers • The start of the assembler block is identified by the #asm directive and terminated with #endasm • All the code between these points must conform to the PIC assembler syntax 13 Microcontrollers Assembler Block #include "16F877A.h" #use delay(clock=4000000) #int_ext void isrext() { output_low(PIN_D0); } void main() { enable_interrupts(int_ext); delay_ms(100); while(input(PIN_B0)); enable_interrupts(global); ext_int_edge(L_TO_H); #asm Start: BSF 8,0 BCF 8,0 GOTO Start #endasm } 14 Microcontrollers Assembler Block 15 C Code Microcontrollers #include "16F877A.h" #use delay(clock=4000000) #int_ext void isrext() { output_low(PIN_D0); } void main() { enable_interrupts(int_ext); delay_ms(100); while(input(PIN_B0)); enable_interrupts(global); ext_int_edge(L_TO_H); while(1) { output_high(PIN_D0); output_low(PIN_D0); } } 16 Microcontrollers C Code 17 ... also be an input to the comparators Microcontrollers COMPARATOR I/O OPERATING MODES Microcontrollers COMPARATOR I/O OPERATING MODES Microcontrollers SINGLE COMPARATOR COMPARATOR VOLTAGE REFERENCE... Microcontrollers COMPARATOR VOLTAGE REFERENCE BLOCK DIAGRAM Microcontrollers COMPARATOR VOLTAGE REFERENCE MODULE Microcontrollers COMPARATOR VOLTAGE REFERENCE MODULE #include #fuses... enable_interrupts(global); ext_int_edge(L_TO_H); #asm Start: BSF 8, 0 BCF 8, 0 GOTO Start #endasm } 14 Microcontrollers Assembler Block 15 C Code Microcontrollers #include "16F877A.h" #use delay(clock=4000000) #int_ext