picocode.psm

Quick start guide to using the xilinx Picoblaze 8 bit MCU on B5-X300 Board by Nial Stewart

             ;Interrupt example
             ;
             CONSTANT test_led_port, 02             
             CONSTANT leds_port, 04
             NAMEREG sA, count
             NAMEREG SB, old_count
             ; 
             ;           
      start: ENABLE INTERRUPT
             LOAD count, 01
             LOAD old_count, count
      loop:  SUB old_count, count
             JUMP Z, loop
             OUTPUT count, leds_port
             LOAD old_count, count
             JUMP loop
             ;
             ADDRESS B0
int_routine: ADD count, 01              ;increment count
             LOAD S5, 10
    delay3:  LOAD S4, 7F
    delay2:  LOAD S3, FF
    delay1:  SUB S3, 01
             JUMP NZ, delay1
             SUB S4, 01
             JUMP NZ, delay2
             SUB S5, 01                             
             JUMP NZ, delay3                       
             ;             
             RETURNI ENABLE
             ; 
             ADDRESS FF                 ;set interrupt vector
             JUMP int_routine