Subversion Repositories copyblaze

             ;Interrupt example
             ;
                         waveform_port          .EQU    02      ;bit0 will be data
             counter_port               .EQU    04
             pattern_10101010   .EQU    0xAA
             interrupt_counter  .EQU    sA
             ; 
      start: LOAD       interrupt_counter       , 00                            ;reset interrupt counter
             LOAD       s2                                      , pattern_10101010      ;initial output condition
             EINT                                                                                       ; enable interrupts
             ;
 drive_wave: OUTPUT s2, waveform_port
             LOAD       s0, 0x07                            ;delay size
       loop: SUB        s0, 0x01                             ;delay loop
             JUMP       NZ, loop
             XOR        s2, 0xFF                             ;toggle waveform
             JUMP       drive_wave
             ;
                         
             .ORG       0x080
int_routine: 
                         ADD    interrupt_counter, 01              ;increment counter
             OUTPUT interrupt_counter, counter_port
             RETI       ENABLE
             ; 
             .ORG       0x3FF                            ;set interrupt vector
             JUMP int_routine